Línea de investigación:

Zona costera

Aunque representa solo el 10% de la superficie del océano, la zona costera alberga el 90% de todas las especies marinas y presenta dinámicas capaces de modular el clima regional y generar efectos globales. Las principales ciudades chilenas están ubicadas en esta área y se ven cada vez más expuestas a los impactos del cambio climático. Para el (CR)2, la investigación en la zona costera aborda la influencia de la variabilidad climática y el forzamiento antropogénico en el océano y el fondo marino costeros en zonas clave de surgencia en Chile, así como en los sistemas socioecológicos contenidos.

El fenómeno de surgencia costera (ascenso de aguas profundas ricas en nutrientes) favorece el desarrollo de la industria pesquera en nuestro país. Evaluar los riesgos e impactos asociados a esta actividad requerirá una mejor observación y modelado por parte de nuestros investigadores, así como el diseño y la implementación de acciones de adaptación y mitigación.

Las floraciones microalgales, la eutrofización, así como la mayor incidencia de tormentas y marejadas plantean nuevos desafíos para la gobernanza en las costas chilenas. La regulación en esta zona es diversa y compleja, lo que genera problemas institucionales que deben abordarse desde la línea de investigación.

Las proyecciones climáticas para Chile indican cambios que los regímenes de vientos regionales que favorecerán la surgencia costera. Además, se espera que la disponibilidad de agua dulce se vea afectada por los cambios en los sistemas de precipitación. Estas tendencias pueden afectar el flujo de calor, los aerosoles y la concentración de gases en la costa chilena, entre otros impactos. Por esta razón, los esfuerzos de la línea de investigación se centrarán en el forzamiento climático actual para comprender los procesos que pueden tener implicaciones climáticas, como las modificaciones en la advección o la circulación estuarina.

INVESTIGADOR PRINCIPAL

CO-INVESTIGADORA PRINCIPAL

INVESTIGADORES ASOCIADOS

INVESTIGADOR JORNADA COMPLETA

INVESTIGADORES ADJUNTOS

INVESTIGADORAS POSTDOCTORALES

INVESTIGADORA COLABORADORA

ESTUDIANTES

Nombre Apellido
Catalina Josefa Barra Robles
Cristóbal Garrido
Diego Campos
Diego Silva Diaz
DIEGO NICOLÁS SEGURA CÁCERES
Efraín Valencia
Felipe Matus
Felipe Toledo
Felipe Vargas
Flor Uribe Ruiz
Francisca Clemo
Franco Retamal
Giovanni Testa
Isadora Fernanda León Soto
Javier Tamayo Leiva
José Ignacio Arroyo González
Macarena Troncoso
María Belén de la Torre Barra
María del Pilar Aparicio Rizzo
María José Araya Lobos
Marianne Buscaglia
Maura Francisca Araneda Silva
Maximo Quezada
Mirko Del Hoyo
Pablo Garrido
Pablo Vergara
Patricio Morales Pacheco
Reynier Bada
Sandy Elizabeth Tenorio Sanchéz
Sergio Guajardo Leiva
Susana Rodríguez Marconi
Valeria Moreno Rudloff
Vanessa Alejandra Carril Pardo

Noticias relacionadas

Línea de InvestigaciónAñoAutoresTítuloRevistaFicha de PublicaciónDOIAbstractAccesoPáginasVolumenIndexKey Words
Zonas Costeras2017Galán, A., Thamdrup, B., Saldías, G. S., Farías, L.Vertical segregation among pathways mediating nitrogen loss (N2 and N2O production) across the oxygen gradient in a coastal upwelling ecosystemBiogeosciences10.5194/bg-14-4795-2017The upwelling system off central Chile (36.5 S) is seasonally subjected to oxygen (O2)-deficient waters, with a strong vertical gradient in O2 (from oxic to anoxic conditions) that spans a few metres (30-50€m interval) over the shelf. This condition inhibits and/or stimulates processes involved in nitrogen (N) removal (e.g. anammox, denitrification, and nitrification). During austral spring (September 2013) and summer (January 2014), the main pathways involved in N loss and its speciation, in the form of N2 and/or N2O, were studied using 15N-tracer incubations, inhibitor assays, and the natural abundance of nitrate isotopes along with hydrographic information. Incubations were developed using water retrieved from the oxycline (25€m depth) and bottom waters (85€m depth) over the continental shelf off Concepción, Chile. Results of 15N-labelled incubations revealed higher N removal activity during the austral summer, with denitrification as the dominant N2-producing pathway, which occurred together with anammox at all times. Interestingly, in both spring and summer maximum potential N removal rates were observed in the oxycline, where a greater availability of oxygen was observed (maximum O2 fluctuation between 270 and 40€μmol€L'1) relative to the hypoxic bottom waters ( < €20€μmol€O2€L'1). Different pathways were responsible for N2O produced in the oxycline and bottom waters, with ammonium oxidation and dissimilatory nitrite reduction, respectively, as the main source processes. Ammonium produced by dissimilatory nitrite reduction to ammonium (DNiRA) could sustain both anammox and nitrification rates, including the ammonium utilized for N2O production. The temporal and vertical variability of /15N-NO3' confirms that multiple N-cycling processes are modulating the isotopic nitrate composition over the shelf off central Chile during spring and summer. N removal processes in this coastal system appear to be related to the availability and distribution of oxygen and particles, which are a source of organic matter and the fuel for the production of other electron donors (i.e. ammonium) and acceptors (i.e. nitrate and nitrite) after its remineralization. These results highlight the links between several pathways involved in N loss. They also establish that different mechanisms supported by alternative N substrates are responsible for substantial accumulation of N2O, which are frequently observed as hotspots in the oxycline and bottom waters. Considering the extreme variation in oxygen observed in several coastal upwelling systems, these findings could help to understand the ecological and biogeochemical implications due to global warming where intensification and/or expansion of the oceanic OMZs is projected.https://www.biogeosciences.net/14/4795/2017/4795-4813vol.14Thomson Reuters ISIbioassay, biogeochemical cycle, bottom water, continental shelf, denitrification, ecosystem dynamics, environmental gradient, global warming, nitrogen, nitrogen cycle, organic matter, oxygen, oxygen minimum layer, tracer, upwelling, vertical profile, chile
Zonas Costeras2017Hamisi, Mi., Lugomela, C., Lyimo, Tj., Bergman, B., Díez, B.Plankton composition, biomass, phylogeny and toxin genes in Lake Big Momela, TanzaniaAfrican Journal of Aquatic Science10.2989/16085914.2017.1334621
Lake Big Momela, one of the East African soda lakes in Northern Tanzania characterised by highly saline-alkaline conditions, making them inhospitable to a range of organisms, although supporting massive growths of some adapted planktonic microorganisms that serve as food for birds, such as Lesser Flamingo. The temporal dynamics of plankton, with an emphasis on cyanobacteria, were examined in 2007 using morphological traits and ribosomal genetic markers (16S and 18S rRNA). Cyanobacterial genes encoding for hepatotoxins (mcyE and ndaF) were also screened. Rotifers and copepods dominated the zooplankton, whereas cyanobacteria, such as Anabaenopsis elenkinii and Arthrospira fusiformis dominated the phytoplankton community, and these being related to representatives in other East African soda lakes. The cyanobacteria community also showed distinct seasonal patterns influenced by environmental parameters, mainly salinity, pH and nitrate. Significant positive correlations were found between phytoplankton abundance and nitrate concentrations (r = 0.617, p = 0.033). No signals of the hepatotoxin synthetase genes mcyE and ndaF were retrieved from cyanobacteria during the whole year. In general, our data illustrate the presence of rich planktonic communities, including some unique and potentially endemic cyanobacteria.https://www.tandfonline.com/doi/full/10.2989/16085914.2017.1334621109-121vol.42Thomson Reuters ISI
Zonas Costeras2017Molina, A., Falvey, M., Rondanelli, R.A solar radiation database for ChileScientific Reports10.1038/s41598-017-13761-x
Chile hosts some of the sunniest places on earth, which has led to a growing solar energy industry in recent years. However, the lack of high resolution measurements of solar irradiance becomes a critical obstacle for both financing and design of solar installations. Besides the Atacama Desert, Chile displays a large array of "solar climates" due to large latitude and altitude variations, and so provides a useful testbed for the development of solar irradiance maps. Here a new public database for surface solar irradiance over Chile is presented. This database includes hourly irradiance from 2004 to 2016 at 90 m horizontal resolution over continental Chile. Our results are based on global reanalysis data to force a radiative transfer model for clear sky solar irradiance and an empirical model based on geostationary satellite data for cloudy conditions. The results have been validated using 140 surface solar irradiance stations throughout the country. Model mean percentage error in hourly time series of global horizontal irradiance is only 0.73%, considering both clear and cloudy days. The simplicity and accuracy of the model over a wide range of solar conditions provides confidence that the model can be easily generalized to other regions of the world.http://www.nature.com/articles/s41598-017-13761-xvol.7Thomson Reuters ISI
Zonas Costeras2017Shaffer, G., Fernández Villanueva, E., Rondanelli, R., Pedersen, J. O. P., Olsen, S. M., Huber, M.Implementation of methane cycling for deep time, global warming simulations with the DCESS Earth System Model (Version 1.2)
Geoscientific Model Development
10.5194/gmd-10-4081-2017Geological records reveal a number of ancient, large and rapid negative excursions of the carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth system over a short duration. These injections may have forced strong global warming events, sometimes accompanied by mass extinctions such as the Triassic-Jurassic and end-Permian extinctions 201 and 252 million years ago, respectively. In many cases, evidence points to methane as the dominant form of injected carbon, whether as thermogenic methane formed by magma intrusions through overlying carbon-rich sediment or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth system models for addressing such events should include a comprehensive treatment of methane cycling but such a treatment has often been lacking. Here we implement methane cycling in the Danish Center for Earth System Science (DCESS) model, a simplified but well-tested Earth system model of intermediate complexity. We use a generic methane input function that allows variation in input type, size, timescale and ocean–atmosphere partition. To be able to treat such massive inputs more correctly, we extend the model to deal with ocean suboxic/anoxic conditions and with radiative forcing and methane lifetimes appropriate for high atmospheric methane concentrations. With this new model version, we carried out an extensive set of simulations for methane inputs of various sizes, timescales and ocean–atmosphere partitions to probe model behavior. We find that larger methane inputs over shorter timescales with more methane dissolving in the ocean lead to ever-increasing ocean anoxia with consequences for ocean life and global carbon cycling. Greater methane input directly to the atmosphere leads to more warming and, for example, greater carbon dioxide release from land soils. Analysis of synthetic sediment cores from the simulations provides guidelines for the interpretation of real sediment cores spanning the warming events. With this improved DCESS model version and paleo-reconstructions, we are now better armed to gauge the amounts, types, timescales and locations of methane injections driving specific, observed deep-time, global warming events.https://www.geosci-model-dev.net/10/4081/2017/4081-4103vol.10 is.11Thomson Reuters ISIair-sea interaction, anoxic conditions, carbon cycle, carbon dioxide, carbon isotope, climate modeling, extinction, global warming, jurassic, marine sediment, methane, permian, radiative forcing, sediment core, simulation, suboxic conditions, terrestrial environment, triassic, denmark
Zonas Costeras2017Toledo, F., Rodriguez, R., Rondanelli, R., Aguirre, R., Diaz, M.SDR Cloud Radar development with reused radio telescope componentsIEEE Geoscience and Remote Sensing10.1109/GRSS-CHILE.2017.7996016The ongoing implementation of a fog observatory in a coastal fog forest in northern Chile is expected to provide valuable information to improve our comprehension of these ecosystems alongside retrieving valuable data to fog scientists. Observing this opportunity and the increase on radio astronomy instrumental it is proposed to develop a low-cost Cloud Radar reutilizing obsolete but operative radio telescope components and software defined radios for modulation. Only preliminary tests have been conducted so far to test the viability of this approach. These tests show that it is in fact possible to build an emitter and receiver operating at 35 GHz using radio telescope components as a Radio Frequency front-end, and that the detected echo coming from the signal is affected by the presence of liquid water droplets in the air. Further development is being carried on the prototype to enable the detection of fog droplets in the boundary layer up to 2 km of height.http://ieeexplore.ieee.org/document/7996016/01/05/18vol.published onlineNot indexed
Zonas Costeras2018Alcamán-Arias, M.E., Pedrós-Alió, C., Tamames, J., Fernández, C., Pérez-Pantoja, D., Vásquez, M., Díez, B.Frontiers in Microbiology10.3389/fmicb.2018.02353Composition, carbon and nitrogen uptake, and gene transcription of microbial mat communities in Porcelana neutral hot spring (Northern Chilean Patagonia) were analyzed using metagenomics, metatranscriptomics and isotopically labeled carbon ((HCO3)-C-13) and nitrogen ((NH4Cl)-N-15 and (KNO3)-N-15) assimilation rates. The microbial mat community included 31 phyla, of which only Cyanobacteria and Chloroflexi were dominant. At 58 degrees C both phyla co-occurred, with similar contributions in relative abundances in metagenomes and total transcriptional activity. At 66 degrees C, filamentous anoxygenic phototrophic Chloroflexi were >90% responsible for the total transcriptional activity recovered, while Cyanobacteria contributed most metagenomics and metatranscriptomics reads at 48 degrees C. According to such reads, phototrophy was carried out both through oxygenic photosynthesis by Cyanobacteria (mostly Mastigocladus) and anoxygenic phototrophy due mainly to Chloroflexi. Inorganic carbon assimilation through the Calvin-Benson cycle was almost exclusively due to Mastigocladus, which was the main primary producer at lower temperatures. Two other CO2 fixation pathways were active at certain times and temperatures as indicated by transcripts: 3-hydroxypropionate (3-HP) bi-cycle due to Chloroflexi and 3-hydroxypropionate-4-hydroxybutyrate (HH) cycle carried out by Thaumarchaeota. The active transcription of the genes involved in these C-fixation pathways correlated with high in situ determined carbon fixation rates. In situ measurements of ammonia assimilation and nitrogen fixation (exclusively attributed to Cyanobacteria and mostly to Mastigocladus sp.) showed these were the most important nitrogen acquisition pathways at 58 and 48 degrees C. At 66 degrees C ammonia oxidation genes were actively transcribed (mostly due to Thaumarchaeota). Reads indicated that denitrification was present as a nitrogen sink at all temperatures and that dissimilatory nitrate reduction to ammonia (DNRA) contributed very little. The combination of metagenomic and metatranscriptomic analysis with in situ assimilation rates, allowed the reconstruction of day and night carbon and nitrogen assimilation pathways together with the contribution of keystone microorganisms in this natural hot spring microbial mat.https://www.frontiersin.org/article/10.3389/fmicb.2018.02353/fullVol.9Thomson Reuters ISIcarbon and nitrogen assimilation, cyanobacteria, metagenomics, metatranscriptomics, microbial mat, neutral hot spring, photosynthesis
Zonas Costeras2018Aguirre, C, García-Loyola, S, Testa, G, Silva, D, Farías, L.Insight into anthropogenic forcing on coastal upwelling off south-central ChileElem Sci Anth10.1525/elementa.314Coastal upwelling systems off the coasts of Peru and Chile are among the most productive marine ecosystems in the world, sustaining a significant percentage of global primary production and fishery yields. Seasonal and interannual variability in these systems has been relatively well documented; however, an understanding of recent trends and the influence of climate change on marine processes such as surface cooling and primary productivity is limited. This study presents evidence that winds favorable to upwelling have increased within the southern boundary of the Humboldt Current System (35°–42°S) in recent decades. This trend is consistent with a poleward movement of the influence of the Southeast Pacific Anticyclone and resembles the spatial pattern projected by Global Circulation Models for warming scenarios. Chlorophyll a levels (from 2002 to present) determined by satellite and field-based time-series observations show a positive trend, mainly in austral spring–summer (December–January–February), potentially explained by observed increments in nutrient flux towards surface waters and photosynthetically active radiation. Both parameters appear to respond to alongshore wind stress and cloud cover in the latitudinal range of 35°S to 42°S. In addition, net annual deepening of the mixed layer depth is estimated using density and temperature profiles. Changes in this depth are associated with increasing winds and may explain cooler, more saline, and more productive surface waters, with the latter potentially causing fluctuations in dissolved oxygen and other gases, such as nitrous oxide, sensitive to changes in oxygenation. We argue that these recent changes represent, at least in part, a regional manifestation of the Anthropocene along the Chilean coast.https://www.elementascience.org/article/10.1525/elementa.314/593-605Vol.6 is.1Thomson Reuters ISIdecadal environmental observations and estimates, south-central chile, wind-driven coastal upwelling systems, annual variation, anthropocene, anthropogenic effect, anticyclone, climate change, cloud cover, coastal zone, cooling, dissolved oxygen, estimation method, marine ecosystem, mixed layer, oxygenation, primary production, satellite data, seasonal variation, upwelling, wind stress, chile, humboldt current, pacific ocean, pacific ocean (southeast), peru
Zonas Costeras2018Alcamán-Arias, M., Farías, L., Verdugo, J., Alarcón-Schumacher, T., Díez, B.
Microbial activity during a coastal phytoplankton bloom on the Western Antarctic Peninsula in late summerFEMS Microbiology Letters10.1093/femsle/fny090Phytoplankton biomass during the austral summer is influenced by freezing and melting cycles as well as oceanographic processes that enable nutrient redistribution in the West Antarctic Peninsula (WAP). Microbial functional capabilities, metagenomic and metatranscriptomic activities as well as inorganic 13C- and 15N-assimilation rates were studied in the surface waters of Chile Bay during two contrasting summer periods in 2014. Concentrations of Chlorophyll a (Chla) varied from 0.3 mg m−3 in February to a maximum of 2.5 mg m−3 in March, together with a decrease in nutrients; however, nutrients were never depleted. The microbial community composition remained similar throughout both sampling periods; however, microbial abundance and activity changed with Chla levels. An increased biomass of Bacillariophyta, Haptophyceae and Cryptophyceae was observed along with night-grazing activity of Dinophyceae and ciliates (Alveolates). During high Chla conditions, HCO3− uptake rates during daytime incubations increased 5-fold (>2516 nmol C L−1 d−1), and increased photosynthetic transcript numbers that were mainly associated with cryptophytes; meanwhile night time NO3− (>706 nmol N L−1 d−1) and NH4+ (41.7 nmol N L−1 d−1) uptake rates were 2- and 3-fold higher, respectively, due to activity from Alpha-/Gammaproteobacteria and Bacteroidetes (Flavobacteriia). Due to a projected acceleration in climate change in the WAP, this information is valuable for predicting the composition and functional changes in Antarctic microbial communities.https://academic.oup.com/femsle/article/doi/10.1093/femsle/fny090/49611371574-6968vol.365 is.10Thomson Reuters ISIantarctic microbial communities, bacterioplankton, c and n assimilation pathways, metatranscriptomics, phytoplankton bloom, ammonia, bicarbonate, carbon 13, chlorophyll a, nitrate, nitrogen 15, surface water, bacterial protein, sea water, algal bloom, alphaproteobacteria, antarctica, bacteroidetes, biomass, carbon fixation, coastal waters, concentration (parameters), cryptophyta, diatom, dinoflagellate, gammaproteobacteria, haptophyta, incubation time, metagenomics, microbial activity, microbial community, nitrogen fixation, nonhuman, omics, population abundance, priority journal, salinity, short survey, species composition, summer, water sampling, water temperature, bacterium, chemistry, classification, ecosystem, eukaryote, genetics, growth, development and aging, metabolism, microbiology, microflora, photosynthesis, phytoplankton, season, antarctic regions, bacteria, bacterial proteins, eukaryota, microbiota, seasons, seawater
Zonas Costeras2018Alcorta, J., Espinoza, S., Viver, T., Alcamán-Arias, M., Trefault, N., Rosselló-Móra, R., Díez, B.
Temperature modulates Fischerella thermalis ecotypes in Porcelana Hot Spring
Systematic and Applied Microbiology
10.1016/j.syapm.2018.05.006
In the Porcelana Hot Spring (Northern Patagonia), true-branching cyanobacteria are the dominant primary producers in microbial mats, and they are mainly responsible for carbon and nitrogen fixation. However, little is known about their metabolic and genomic adaptations at high temperatures. Therefore, in this study, a total of 81 Fischerella thermalis strains (also known as Mastigocladus laminosus) were isolated from mat samples in a thermal gradient between 61–46 °C. The complementary use of proteomic comparisons from these strains, and comparative genomics of F. thermalis pangenomes, suggested that at least two different ecotypes were present within these populations. MALDI-TOF MS analysis separated the strains into three clusters; two with strains obtained from mats within the upper temperature range (61 and 54 °C), and a third obtained from mats within the lower temperature range (51 and 46 °C). Both groups possessed different but synonymous nifH alleles. The main proteomic differences were associated with the abundance of photosynthesis-related proteins. Three F. thermalis metagenome assembled genomes (MAGs) were described from 66, 58 and 48 °C metagenomes. These pangenomes indicated a divergence of orthologous genes and a high abundance of exclusive genes at 66 °C. These results improved the current understanding of thermal adaptation of F. thermalis and the evolution of these thermophilic cyanobacterial species.https://linkinghub.elsevier.com/retrieve/pii/S0723202018302297Thomson Reuters ISI
Zonas Costeras2018Arriagada, L., Rojas, O., Arumí, J. L., Munizaga, J., Rojas, C., Farias, L., Vega, C.A new method to evaluate the vulnerability of watersheds facing several stressors: A case study in mediterranean ChileScience of The Total Environment10.1016/j.scitotenv.2018.09.237Freshwater systems are subjected to multiple anthropogenic stressors and natural disturbances that act as debilitating agents and modifiers of river systems, causing cumulative and synergistic effects that deteriorate their health and result in watershed vulnerability. This study proposes an easy-to-apply spatial method of watershed vulnerability evaluation using Geographic Information Systems (GIS) in the Andalién River watershed, located in the Chilean mediterranean. A watershed vulnerability index (WVI) based on three sub-indices – anthropogenic stressors, environmental fragility and natural disturbances – was developed. To determine the index grouping weights, expert surveys were carried out using the Delphi method. We subsequently normalized and integrated the factors of each sub-index with relative weights. The ranges of each thematic layer were re-classified to establish vulnerability scores. The watershed was divided into three sections: headwaters zone, transfer zone and depositional zone. The watershed vulnerability index showed that 41% of the watershed had very low vulnerability and 42% had medium vulnerability, while only 1% – in the depositional zone – had high vulnerability. A one-way ANOVA was carried out to analyze the vulnerability differences among the three sections of the watershed; it showed significant differences (F (2, 16) = 8.15: p < 0.05). The a posteriori test showed differences between the headwaters and depositional zones (Tukey test, p = 0.005) and between the transfer and depositional zones (Tukey test, p = 0.014). To validate the WVI, water quality was measured at 16 stations in the watershed; there was a significant correlation between vulnerability level and NO2 − levels (r = 0.8; p = 0.87; α = 0.05) and pH (r = 0.8; p = 0.80; α = 0.05). The WVI showed the cumulative effects of multiple stressors in the depositional zone of the watershed. This is the first study to evaluate and validate non-regulated watershed vulnerability with GIS using multiple anthropogenic and natural stressors.https://linkinghub.elsevier.com/retrieve/pii/S00489697183368171517-1533vol.651Thomson Reuters ISIanthropogenic stressors, environmental fragility, geographic information system, integrated management, natural disturbances, deposition, geographic information systems, information management, information systems, information use, water quality, freshwater systems, multiple stressors, natural disturbance, vulnerability evaluations, vulnerability index, watersheds, anthropogenic effect, disturbance, environmental assessment, gis, headwater, integrated approach, vulnerability, watershed, article, chile, controlled study, environmental erosion, environmental impact, landfill, priority journal, spatial analysis, thematic analysis, water analysis, water management, water pollution, water supply, andalien river, bio bio
Agua y Extremos; Zonas Costeras; Transversal
2018Bozkurt, D., Rondanelli, R., Marín, J. C., Garreaud, R.
Foehn Event Triggered by an Atmospheric River Underlies Record-Setting Temperature Along Continental AntarcticaJournal of Geophysical Research: Atmospheres10.1002/2017JD027796A record‐setting temperature of 17.5°C occurred on 24 March 2015 at the Esperanza station located near the northern tip of the Antarctic Peninsula (AP). We studied the event using surface station data, satellite imagery, reanalysis data, and numerical simulations. The Moderate Resolution Imaging Spectroradiometer Antarctic Ice Shelf Image Archive provides clear evidence for disintegration and advection of sea ice, as well as the formation of melt ponds on the ice sheet surface at the base of the AP mountain range. A deep low‐pressure center over the Amundsen‐Bellingshausen Sea and a blocking ridge over the southeast Pacific provided favorable conditions for the development of an atmospheric river with a northwest‐southeast orientation, directing warm and moist air toward the AP, and triggering a widespread foehn episode. A control simulation using a regional climate model shows the existence of local topographically induced warming along the northern tip of the AP (∼60% of the full temperature signal) and the central part of the eastern AP (>90% of the full temperature signal) with respect to a simulation without topography. These modeling results suggest that more than half of the warming experienced at Esperanza can be attributed to the foehn effect (a local process), rather than to the large‐scale advection of warm air from the midlatitudes. Nevertheless, the local foehn effect also has a large‐scale advection component, since the atmospheric river provides water vapor for orographic precipitation enhancement and latent heat release, which makes it difficult to completely disentangle the role of local versus large‐scale processes in explaining the extreme event.http://doi.wiley.com/10.1002/2017JD0277963871-3892vol.123 is.8Thomson Reuters ISIatmospheric river, climate variability, extreme high temperature, foehn wind, meteorology, regional climate modeling, advection, atmospheric moisture, climate change, climate modeling, extreme event, foehn, high temperature, ice shelf, modis, regional climate, temperature, amundsen sea, antarctic peninsula, antarctica, bellingshausen sea, pacific ocean, pacific ocean (southeast), southern ocean, west antarctica, esperanza
Zonas Costeras2018Dätwyler Ch., Neukom R., Abram N., Gallant A., Grosjean M., Jacques-Coper M., Karoly D., Villalba R.
Teleconnection stationarity, variability and trends of the Southern Annular Mode (SAM) during the last millenniumClimate Dynamics10.1007/s00382-017-4015-0The Southern Annular Mode (SAM) is the leading mode of atmospheric interannual variability in the Southern Hemisphere (SH) extra-tropics. Here, we assess the stationarity of SAM spatial correlations with instrumental and paleoclimate proxy data for the past millennium. The instrumental period shows that temporal non-stationarities in SAM teleconnections are
not consistent across the SH land areas. This suggests that the influence of the SAM index is modulated by regional effects.
However, within key-regions with good proxy data coverage (South America, Tasmania, New Zealand), teleconnections are mostly stationary over the instrumental period. Using different stationarity criteria for proxy record selection, we provide
new austral summer and annual mean SAM index reconstructions over the last millennium. Our summer SAM reconstructions are very robust to changes in proxy record selection and the selection of the calibration period, particularly on the multi-decadal timescale. In contrast, the weaker performance and lower agreement in the annual mean SAM reconstructions
point towards changing teleconnection patterns that may be particularly important outside the summer months. Our results clearly portend that the temporal stationarity of the proxy-climate relationships should be taken into account in the design of comprehensive regional and hemispherical climate reconstructions. The summer SAM reconstructions show no significant relationship to solar, greenhouse gas and volcanic forcing, with the exception of an extremely strong negative anomaly following the AD 1257 Samalas eruption. Furthermore, reconstructed pre-industrial summer SAM trends are very similar to
trends obtained by model control simulations. We find that recent trends in the summer SAM lie outside the 5–95% range of pre-industrial natural variability.
http://link.springer.com/10.1007/s00382-017-4015-01-19Thomson Reuters ISIclimate change, climate reconstruction, holocene, paleoclimate, southern hemisphere, annual variation, climate variation, reconstruction, teleconnection, trend analysis, australia, new zealand, south america, tasmania
Zonas Costeras2018Farías L., Bello E., Arancibia G., Fernandez J.Distribution of dissolved methane and nitrous oxide in Chilean coastal systems of the Magellanic Sub-Antarctic region (50°–55°S)Estuarine, Coastal and Shelf Science10.1016/j.ecss.2018.10.020Nitrous oxide (N2O) and methane (CH4) are greenhouse gases and active in the depletion of the ozone layer. These gases, originating from both anthropogenic and natural sources, are mainly released to the atmosphere from coastal areas, including continental shelves, estuaries and fjords. Surface distribution of dissolved N2O and CH4 during the austral spring were described within the Magellanic Sub-Antarctic region (50–55°S, Chile) with a coastal area that has a complex system of fjords, channels, gulf and, bays. A narrow range of N2O concentrations were observed from under-saturations (∼65%), as result of freshwater/glacial flow into fjord heads, to slight super-saturations (∼120–150%) in fjord mouths and adjacent marine zones. One exception was Otway Sound, where a penguin colony is situated, with N2O levels of up to 218%. In contrast, CH4 concentrations presented a wide range of saturations between 47.9% and 483%, with a spatial distribution that mainly corresponded to the type of hydrographic/geomorphologic basin; in the southern Patagonian Andes (mostly covered by the southern Ice Fields) CH4 levels varied between 65 and 80% in the marine area, and 180% saturation in the channels and fjords; whereas in the southern Patagonian tableland (Magellan Strait) higher CH4 concentrations, up to 483% saturation, were observed apparently associated with continental inputs (peatland and tundra vegetation). N2O concentrations were positively correlated with salinity and nutrients, indicating that the majority of N2O and nutrients (except silicate) originated from the Sub-Antarctic Water Mass (SAAW), which mixes with N2O-depleated freshwater. However, CH4 concentrations did not correlate with any oceanographic variables, suggesting that they originate from local marine/terrestrial interactions. The Magellanic Sub-Antarctic region acts as a modest source of N2O and CH4, to the atmosphere with effluxes of 6.20 ± 10.13 and 16.88 ± 27.04 μmol m−2 d−1 respectively. Due to climate change and a growth in anthropogenic activities such as salmon farming, future emissions of N2O and CH4 within this remote region remain uncertain.https://linkinghub.elsevier.com/retrieve/pii/S0272771418304785229-240Vol.215Thomson Reuters ISIchilean fjords, magellanic sub-antarctic region, methane, nitrous oxide, coastal zone, concentration (composition), dissolved gas, fjord, freshwater, greenhouse gas, ozone depletion, saturation, spring (season), subantarctic region, andes, antarctica, australia, chile, magellan strait, otway range, patagonia, victoria australia, spheniscidae
Zonas Costeras2018Farías, L., Faúndez, J., Sanhueza-Guevara, S.Temporal dynamics of dissolved inorganic nitrogen (DIN) in the aphotic layer of a coastal upwelling system with variable dissolved oxygenJournal of Marine Systems10.1016/j.jmarsys.2018.06.001Dissolved O2 (DO) concentration is critical to determining ecosystem functions such as organic matter respiration, which can favor fixed nitrogen loss and the accumulation of compounds such as NH4+. This dynamic is observed in central Chile's coastal upwelling system (36 °S), which presents seasonally O2 deficient waters and high biological productivity. Temporal dynamics for dissolved inorganic nitrogen (DIN: NO3−, NO2− and NH4+) are analyzed based on a ten year time series of monthly measurements of DO and DIN and a three year record of absolute DIN uptake rates (ρDIN), respective turnover rates (νDIN), and O2 utilization rates (OUR). Observed O2 deficit gradually increases from hypoxia to near anoxia as the system becomes more productive, favoring the accumulation of NO2− and NH4+. Three temporal phases within the aphotic layer were distinguished: (I) DO > 62 μmol L−1 (May to August), (II) 5 < DO < 62 μmol L−1 (September to December) and (III) DO < 5 μmol L−1 (January to April). From phase I to III, DO and NO3− inventories decreased by eight and two times, respectively, while NH4+ and NO2 inventories increased two- and five-fold, respectively. Uptake rates for NH4+ varied from 0.23 to 450 nmol N L−1 d−1 and from 1.42 to 184 nmol N L−1 d−1 for NO3−. Notably, integrated ρNH4+ increased during phase III, generating a NH4+ turnover time of 12–29 days; whereas integrated ρNO3− peaked during phase II, and removed the NO3− pool over an extended turnover time (>820 days). Integrated OUR gradually increased from phase I to III (from 225 to 422 mmol m−2 d−1), with DO pools replenished over 2.3 to 26 days. NH4+ regeneration rates ranged from 34 to 62 mmol m−2 d−1 and NH4+ pools were replenished within a few days. Variation in DO, which regulates N cycling, may explain the accumulation of N-species within the aphotic layer. Observed trends could be extrapolated to scenarios of upwelling-favorable winds, eutrophication and hypoxia.https://linkinghub.elsevier.com/retrieve/pii/S0924796317302075Thomson Reuters ISIaphotic layer, coastal upwelling, microbial din metabolism, oxygen utilization rate, coastal engineering, dissolution, eutrophication, lakes, nitrogen, nitrogen oxides, biological productivity, dissolved inorganic nitrogens, ecosystem functions, oxygen utilization, regeneration rate, temporal dynamics, dissolved oxygen, coastal zone, dissolved inorganic nitrogen, hypoxia, nitrogen cycle, temporal variation, time series analysis, upwelling, chile
Zonas Costeras2018Fernández-Gómez, B., Díez, B., Polz, M. F., Arroyo, J. I., Alfaro, F. D., Marchandon, G., Sanhueza, C., Farías, L., Trefault, N., Marquet, P. A., Molina-Montenegro, M. A., Sylvander, P., Snoeijs-Leijonmalm, P.Bacterial community structure in a sympagic habitat expanding with global warming: brackish ice brine at 85–90 °NThe ISME Journal10.1038/s41396-018-0268-9Larger volumes of sea ice have been thawing in the Central Arctic Ocean (CAO) during the last decades than during the past 800,000 years. Brackish brine (fed by meltwater inside the ice) is an expanding sympagic habitat in summer all over the CAO. We report for the first time the structure of bacterial communities in this brine. They are composed of psychrophilic extremophiles, many of them related to phylotypes known from Arctic and Antarctic regions. Community structure displayed strong habitat segregation between brackish ice brine (IB; salinity 2.4–9.6) and immediate sub-ice seawater (SW; salinity 33.3–34.9), expressed at all taxonomic levels (class to genus), by dominant phylotypes as well as by the rare biosphere, and with specialists dominating IB and generalists SW. The dominant phylotypes in IB were related to Candidatus Aquiluna and Flavobacterium, those in SW to Balneatrix and ZD0405, and those shared between the habitats to Halomonas, Polaribacter and Shewanella. A meta-analysis for the oligotrophic CAO showed a pattern with Flavobacteriia dominating in melt ponds, Flavobacteriia and Gammaproteobacteria in solid ice cores, Flavobacteriia, Gamma- and Betaproteobacteria, and Actinobacteria in brine, and Alphaproteobacteria in SW. Based on our results, we expect that the roles of Actinobacteria and Betaproteobacteria in the CAO will increase with global warming owing to the increased production of meltwater in summer. IB contained three times more phylotypes than SW and may act as an insurance reservoir for bacterial diversity that can act as a recruitment base when environmental conditions change.http://www.nature.com/articles/s41396-018-0268-9Thomson Reuters ISIbacterium, brackish water, brine, community structure, dominance, environmental conditions, extremophile, generalist, global warming, meltwater, oligotrophic environment, sea ice, seawater, specialist, arctic and antarctic, arctic ocean, actinobacteria, alphaproteobacteria, bacteria (microorganisms), balneatrix, betaproteobacteria, flavobacterium, gammaproteobacteria, halomonas, polaribacter, shewanella, sea water, antarctica, arctic, classification, ecosystem, flavobacteriaceae, greenhouse effect, ice cover, isolation and purification, microbiology, salinity, season, antarctic regions, arctic regions, bacteria, seasons
Zonas Costeras2018Fuentes, S., Arroyo, J.I., Rodríguez-Marconi, S., Masotti, I., Alarcón-Schumacher, T., Polz, M.F., Trefault, N., de la Iglesia, R., Díez, B.Summer phyto- and bacterioplankton communities during low and high productivity scenarios in the Western Antarctic PeninsulaPolar Biology10.1007/s00300-018-2411-5Phytoplankton blooms taking place during the warm season drive high productivity in Antarctic coastal seawaters. Important temporal and spatial variations exist in productivity patterns, indicating local constraints influencing the phototrophic community. Surface water in Chile Bay (Greenwich Island, South Shetlands) is influenced by freshwater from the melting of sea ice and surrounding glaciers; however, it is not a widely studied system. The phyto- and bacterioplankton communities in Chile Bay were studied over two consecutive summers; during a low productivity period (chlorophyll a < 0.05 mg m−3) and an ascendant phototrophic bloom (chlorophyll a up to 2.38 mg m−3). Microbial communities were analyzed by 16S rRNA—including plastidial—gene sequencing. Diatoms (mainly Thalassiosirales) were the most abundant phytoplankton, particularly during the ascendant bloom. Bacterioplankton in the low productivity period was less diverse and dominated by a few operational taxonomic units (OTUs), related to Colwellia and Pseudoalteromonas. Alpha diversity was higher during the bloom, where several Bacteroidetes taxa absent in the low productivity period were present. Network analysis indicated that phytoplankton relative abundance was correlated with bacterioplankton phylogenetic diversity and the abundance of several bacterial taxa. Hubs—the most connected OTUs in the network—were not the most abundant OTUs and included some poorly described taxa in Antarctica, such as Neptunomonas and Ekhidna. In summary, the results of this study indicate that in Antarctic Peninsula coastal waters, such as Chile Bay, higher bacterioplankton community diversity occurs during a phototrophic bloom. This is likely a result of primary production, providing a source of fresh organic matter to bacterioplankton. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.http://link.springer.com/10.1007/s00300-018-2411-5Thomson Reuters ISI16s rrna gene sequencing, antarctic peninsula, bacterioplankton, phytoplankton, algal bloom, community composition, genetic analysis, organic matter, phylogenetics, relative abundance, rna, sea ice, seasonality, seawater, summer, antarctica, chilean margin, pacific ocean, west antarctica, bacillariophyta, bacteria (microorganisms), bacteroidetes, colwellia, neptunomonas, otus, pseudoalteromonas, thalassiosirales
Zonas Costeras2018Guajardo-Leiva, S., Pedrós-Alió, C., Salgado, O., Pinto, F., Díez, B.Active Crossfire Between Cyanobacteria and Cyanophages in Phototrophic Mat Communities Within Hot SpringsFrontiers in Microbiology10.3389/fmicb.2018.02039Cyanophages are viruses with a wide distribution in aquatic ecosystems, that specifically infect Cyanobacteria. These viruses can be readily isolated from marine and fresh waters environments; however, their presence in cosmopolitan thermophilic phototrophic mats remains largely unknown. This study investigates the morphological diversity (TEM), taxonomic composition (metagenomics), and active infectivity (metatranscriptomics) of viral communities over a thermal gradient in hot spring phototrophic mats from Northern Patagonia (Chile). The mats were dominated (up to 53%) by cosmopolitan thermophilic filamentous true-branching cyanobacteria from the genus Mastigocladus, the associated viral community was predominantly composed of Caudovirales (70%), with most of the active infections driven by cyanophages (up to 90% of Caudovirales transcripts). Metagenomic assembly lead to the first full genome description of a T7-like Thermophilic Cyanophage recovered from a hot spring (Porcelana Hot Spring, Chile), with a temperature of 58°C (TC-CHP58). This could potentially represent a world-wide thermophilic lineage of podoviruses that infect cyanobacteria. In the hot spring, TC-CHP58 was active over a temperature gradient from 48 to 66°C, showing a high population variability represented by 1979 single nucleotide variants (SNVs). TC-CHP58 was associated to the Mastigocladus spp. by CRISPR spacers. Marked differences in metagenomic CRISPR loci number and spacers diversity, as well as SNVs, in the TC-CHP58 proto-spacers at different temperatures, reinforce the theory of co-evolution between natural virus populations and cyanobacterial hosts. Considering the importance of cyanobacteria in hot spring biogeochemical cycles, the description of this new cyanopodovirus lineage may have global implications for the functioning of these extreme ecosystems.https://www.frontiersin.org/article/10.3389/fmicb.2018.02039/fullvol.9Thomson Reuters ISIcrispr, cyanophages, hot-springs, phototrophic microbial mat, thermophilic cyanobacteria, crispr associated protein, aquatic environment, article, cyanobacterium, cyanophage, high throughput sequencing, mastigocladus, metagenomics, microbial diversity, nonhuman, phototrophy, phylogeny, rna extraction, rna sequence, single nucleotide polymorphism, thermal spring, transmission electron microscopy
Zonas Costeras2018Sepulveda-Jauregui, A., Martinez-Cruz, K., Lau, M., Casper, P.Assessment of methane and carbon dioxide emissions in two sub-basins of a small acidic bog lake artificially divided 30 years agoFreshwater Biology10.1111/fwb.13182Although lakes are important sources of methane (CH4) and carbon dioxide (CO2) to the atmosphere contributing to global warming, their CH4 and CO2 emissions are rarely assessed. In particular, increasing inputs of terrestrial dissolved organic carbon (DOC) may affect gas dynamics and alter seasonal changes in gas production. Here, we analysed variations in CH4 and CO2 dynamics in sub-basins of an acidic bog lake, which was artificially divided into four quarters three decades ago, leading to divergence in water chemistry and biology. In the divided lake, only the south-west basin (SW) received DOC inputs from an adjacent peat bog, while the north-east basin (NE) was hydrologically disconnected. A year-long determination of CH4 and CO2 production and emission patterns in the two contrasting basins exposed the indirect mechanisms by which DOC supply exercised control on greenhouse gas dynamics in this shallow lake. In both basins, dissolved CH4 was negatively correlated with dissolved oxygen (O2) through the water column, suggesting that aerobic methanotrophy is an important regulator of CH4 emissions in this lake. In contrast, the amount of CO2 stored in oxic and anoxic layers was not significantly different between the basins, suggesting that O2 is not the most important driver of dissolved CO2. Estimated total CH4 and CO2 emissions were 2.1 and 1.7 times lower in the NE basin than in the SW basin, with major CH4 and CO2 emissions occurring during the fall turnover. The differences in CH4 and CO2 emissions suggest that the hydro-physical properties, namely seasonal temperature, the duration of stratification and O2 availability, are the main drivers of CH4 and CO2 emissions to the atmosphere from small shallow lakes under the influence of DOC inputs under global warming pressure.http://doi.wiley.com/10.1111/fwb.13182Thomson Reuters ISIcarbon storage, dissolved greenhouse gases, humic substances, limnology, year-round experiment
Zonas Costeras2018Toledo, F., Garrido, C., Díaz, M., Rondanelli, R., Jorquera, S., Valdivieso, P.AOT Retrieval Procedure for Distributed Measurements With Low-Cost Sun Photometers: AOT RETRIEVAL METHOD FOR SUN PHOTOMETERSJournal of Geophysical Research: Atmospheres10.1002/2017JD027309We propose a new application of inexpensive light-emitting diode (LED)-based Sun photometers, consisting of measuring the aerosol optical thickness (AOT) with high resolution within metropolitan scales. Previously, these instruments have been used at continental scales by the GLOBE program, but this extension is already covered by more expensive and higher-precision instruments of the AERONET global network. For this we built an open source two-channeled LED-based Sun photometer based on previous developments, with improvements in the hardware, software, and modifications on the calibration procedure. Among these we highlight the use of MODTRAN to characterize the effect introduced by using LED sensors in the AOT retrieval, an open design available for the scientific community and a calibration procedure that takes advantage of a CIMEL Sun photometer located within the city, enables the intercomparison of several LED Sun photometers with a common reference. We estimated the root-mean-square error in the AOT retrieved by the prototypes as 0.006 at the 564 nm and 0.009 at the 408 nm. This error is way under the magnitude of the AOT daily cycle variability measured by us in our campaigns, even for distances closer than 15 km. In addition to inner city campaigns, we also show aerosol-tracing applications by measuring AOT variations from the city of Santiago to the Andes glaciers. Measuring AOT at high spatial resolution in urban areas can improve our understanding of urban scale aerosol circulation, providing information for solar energy planning, health policies, and climatological studies, among others.http://doi.wiley.com/10.1002/2017JD0273091113-1131vol.123 is.2Thomson Reuters ISIaot, distributed measurement, sun photometer, aeronet, aerosol, calibration, electrode, energy planning, glacier, metropolitan area, photometer, solar power, spatial resolution, urban area, andes, chile, metropolitana
Zonas Costeras2019Wilson,ST.,Bange ,H.W, Arévalo-Martínez,D.L. ,Barnes, J, Borges, A.V, Brown, I, Bullister,JohnL, Burgos,M, Capelle,D.W., Casso, M, De la Paz, M, Farías, L, Fenwick,L, Ferrón,S,Garcia, G, Glockzin, M, Karl, D.M, Kock,A, Laperriere,S, Law, C.S, Manning,C.C, Marriner,A, Myllykangas,J-P., Pohlman,J.W., Rees, A.P, Santoro,A.E, Torres, M, Tortell, PD, Upstill-Goddard,R.C,.Wisegarver, D.P, Zhang,G.L, Rehder, G.An intercomparison of oceanic methane and nitrous oxide measurementsBiogeosciences10.5194/bg-15-5891-2018Large-scale climatic forcing is impacting oceanic biogeochemical cycles and is expected to influence the water-column distribution of trace gases, including methane and nitrous oxide. Our ability as a scientific community to evaluate changes in the water-column inventories of methane and nitrous oxide depends largely on our capacity to obtain robust and accurate concentration measurements that can be validated across different laboratory groups. This study represents the first formal international intercomparison of oceanic methane and nitrous oxide measurements whereby participating laboratories received batches of seawater samples from the subtropical Pacific Ocean and the Baltic Sea. Additionally, compressed gas standards from the same calibration scale were distributed to the majority of participating laboratories to improve the analytical accuracy of the gas measurements. The computations used by each laboratory to derive the dissolved gas concentrations were also evaluated for inconsistencies (e.g., pressure and temperature corrections, solubility constants). The results from the intercomparison and intercalibration provided invaluable insights into methane and nitrous oxide measurements. It was observed that analyses of seawater samples with the lowest concentrations of methane and nitrous oxide had the lowest precisions. In comparison, while the analytical precision for samples with the highest concentrations of trace gases was better, the variability between the different laboratories was higher: 36% for methane and 27% for nitrous oxide. In addition, the comparison of different batches of seawater samples with methane and nitrous oxide concentrations that ranged over an order of magnitude revealed the ramifications of different calibration procedures for each trace gas. Finally, this study builds upon the intercomparison results to develop recommendations for improving oceanic methane and nitrous oxide measurements, with the aim of precluding future analytical discrepancies between laboratories.https://www.biogeosciences.net/15/5891/2018/5891-5907Vol.15 is.19Thomson Reuters ISI-
Zonas Costeras2018Yevenes, MA., Figueroa, R., Parra., O
Seasonal drought effects on the water quality of the Biobío River, Central Chile
Environmental Science and Pollution Research10.1007/s11356-018-1415-6Quantifying the effect of droughts on ecosystem functions is essential to the development of coastal zone and river management under a changing climate. It is widely acknowledged that climate change is increasing the frequency and intensity of droughts, which can affect important ecosystem services, such as the regional supply of clean water. Very little is understood about how droughts affect the water quality of Chilean high flow rivers. This paper intends to investigate the effect of an, recently identified, unprecedented drought in Chile (2010–2015), on the Biobío River water quality, (36°45′–38°49′ S and 71°00′–73°20′ W), Central Chile. This river is one of the largest Chilean rivers and it provides abundant freshwater. Water quality (water temperature, pH, dissolved oxygen, electrical conductivity, biological oxygen demand, total suspended solids, chloride, sodium, nutrients, and trace metals), during the drought (2010–2015), was compared with a pre-drought period (2000–2009) over two reaches (upstream and downstream) of the river. Multivariate analysis and seasonal Mann-Kendall trend analyses and a Theil-Sen estimator were employed to analyze trends and slopes of the reaches. Results indicated a significant decreased trend in total suspended solids and a slightly increasing trend in water temperature and EC, major ions, and trace metals (chrome, lead, iron, and cobalt), mainly in summer and autumn during the drought. The reduced variability upstream suggested that nutrient and metal concentrations were more constant than downstream. The results evidenced, due to the close relationship between river discharge and water quality, a slightly decline of the water quality downstream of the Biobío River during drought period, which could be attenuated in a post-drought period. These results displayed that water quality is vulnerable to reductions in flow, through historical and emerging solutes/contaminants and induced pH mobilization. Consequently, seasonal changes and a progressive reduction of river flow affect the ecosystem functionality in this key Chilean river. The outcomes from this research can be used to improve how low flow conditions and the effects of a reduction in the river volume and discharge are assessed, which is the case under the scenario of more frequent drought periods.http://link.springer.com/10.1007/s11356-018-1415-613844-13856Vol.25 is,14Thomson Reuters ISIbiobío river, ecosystem functions, mega-drought, river discharge, water quality, water supply, climate change, drought, ecosystem function, ecosystem service, river flow, river management, seasonal variation, water temperature, biobio river, chile, analysis, chemistry, environmental monitoring, river, season, water pollutant, droughts, rivers, seasons, water pollutants, chemical
Zonas Costeras2018Masotti, I., Aparicio-Rizzo, P., Yevenes, M. A., Garreaud, R., Farias, L.The influence of river discharge on nutrient export and phytoplankton biomass off the Central Chile coast (33º-37ºS). Seasonal cycle and interannual variabilityFrontiers in Marine Science10.3389/fmars.2018.00423Using in situ hydro-chemical data and MODIS-SeaWiFS ocean color images as a proxy of river plumes and phytoplankton biomass from 2000 to 2014, this study documents the temporal co-variability of river discharge, plume area, nitrate and phosphate export and phytoplankton biomass in the coastal waters off Central Chile (33º-37ºS). Five major rivers (Maipo, Mataquito, Maule, Itata and Biobío) drain into this region with annual mean discharge ranging from 120 to 1000 m3 s-1. River discharge and coastal plume area present a marked seasonal cycle, reaching maximum values during the winter rainy season (June-September). Export of riverine nutrients also peaks in winter, leading to an increase in phytoplankton biomass within the plumes that can be twice larger than the background values in coastal areas away from the river mouths. Wintertime river discharge, plume area and nutrient export are also correlated at interannual time scales. During a recent extended dry period (2010-2014), river discharges, plume areas and nutrient export clearly decreased by about 50% compared to historical values, reducing significantly the size of the chlorophyll pool within plumes off Central Chile during winter. The potential impacts of droughts are discussed in terms of coastal ecology and primary production, a highly relevant issue considering the projections of a dry climate over Central Chile in the future. Systematic evidence of mega-drought effects upon coastal productivity still does not exist, but it remains a priority to further investigate and quantify these impacts.impressScopuscentral chile, drought, nutrient export, phytoplankton biomass, river discharge, satellite remote sensing
Zonas Costeras2018Masotti, I., Aparicio-Rizzo, P., Yevenes, M. A., Garreaud, R., Farias, L.The influence of river discharge on nutrient export and phytoplankton biomass off the Central Chile coast (33º-37ºS). Seasonal cycle and interannual variabilityFrontiers in Marine Science10.3389/fmars.2018.00423Using in situ hydro-chemical data and MODIS-SeaWiFS ocean color images as a proxy of river plumes and phytoplankton biomass from 2000 to 2014, this study documents the temporal co-variability of river discharge, plume area, nitrate and phosphate export and phytoplankton biomass in the coastal waters off Central Chile (33º-37ºS). Five major rivers (Maipo, Mataquito, Maule, Itata and Biobío) drain into this region with annual mean discharge ranging from 120 to 1000 m3 s-1. River discharge and coastal plume area present a marked seasonal cycle, reaching maximum values during the winter rainy season (June-September). Export of riverine nutrients also peaks in winter, leading to an increase in phytoplankton biomass within the plumes that can be twice larger than the background values in coastal areas away from the river mouths. Wintertime river discharge, plume area and nutrient export are also correlated at interannual time scales. During a recent extended dry period (2010-2014), river discharges, plume areas and nutrient export clearly decreased by about 50% compared to historical values, reducing significantly the size of the chlorophyll pool within plumes off Central Chile during winter. The potential impacts of droughts are discussed in terms of coastal ecology and primary production, a highly relevant issue considering the projections of a dry climate over Central Chile in the future. Systematic evidence of mega-drought effects upon coastal productivity still does not exist, but it remains a priority to further investigate and quantify these impacts.impressScopuscentral chile, drought, nutrient export, phytoplankton biomass, river discharge, satellite remote sensing
Zonas Costeras2019Yevenes, Mariela A.; Lagos, Nelson A.; Farías, Laura; Vargas, Cristian A.Greenhouse gases, nutrients and the carbonate system in the Reloncaví Fjord (Northern Chilean Patagonia): Implications on aquaculture of the mussel, Mytilus chilensis, during an episodic volcanic eruptionScience of The Total Environment10.1016/j.scitotenv.2019.03.037This study investigates the immediate and mid-term effects of the biogeochemical variables input into the Reloncaví fjord (41°40′S; 72°23′O) as a result of the eruption of Calbuco volcano. Reloncaví is an estuarine system supporting one of the largest mussels farming production within Northern Chilean-Patagonia. Field-surveys were conducted immediately after the volcanic eruption (23–30 April 2015), one month (May 2015), and five months posterior to the event (September 2015). Water samples were collected from three stations along the fjord to determine greenhouse gases [GHG: methane (CH 4 ), nitrous oxide (N 2 O)], nutrients [NO 3 − , NO 2 − , PO 4 3− , Si(OH) 4 , sulphate (SO 4 2− )], and carbonate systems parameters [total pH (pHT), temperature, salinity, dissolved oxygen (O 2 ), and total alkalinity (AT)]. Additionally, the impact of physicochemical changes in the water column on juveniles of the produced Chilean blue mussel, Mytilus chilensis, was also studied. Following the eruption, a large phytoplankton bloom led to an increase in pH T , due to the uptake of dissolved-inorganic carbon in photic waters, potentially associated with the runoff of continental soil covered in volcanic ash. Indeed, high surface SO 4 2− and GHG were observed to be associated with river discharges. No direct evidence of the eruption was observed within the carbonate system. Notwithstanding, a vertical pattern was observed, with an undersaturation of aragonite (Ω Ar < 1) both in brackish surface (<3 m) and deep waters (>10 m), and saturated values in subsurface waters (3 to 7 m). Simultaneously, juvenile mussel shells showed maximized length and weight at 4 m depth. Results suggest a localized impact of the volcanic eruption on surface GHG, nutrients and short-term effects on the carbonate system. Optimal conditions for mussel calcification were identified within a subsurface refuge in the fjord. These specific attributes can be integrated into adaptation strategies by the mussel aquaculture industry to confront ocean acidification and changing runoff conditions. © 2019 Elsevier B.V.https://linkinghub.elsevier.com/retrieve/pii/S004896971931015049-61vol.669.0 is.Thomson Reuters ISIcarbonates system, chilean patagonian fjord, mussel farming, nutrients, volcanic event, alkalinity, aquaculture, biomineralization, carbonation, dissolved oxygen, greenhouse gases, molluscs, nitrogen oxides, runoff, sulfur compounds, surface discharges, adaptation strategies, aquaculture industry, dissolved inorganic carbon, ocean acidifications, physico-chemical changes, volcanoes, calcium carbonate, carbonic acid, methane, nitrous oxide, sulfate, surface water, sea water, adaptive management, biogeochemical cycle, carbonate system, chemical oceanography, greenhouse gas, mussel culture, nutrient, ocean acidification, volcanic eruption, article, chilean, estuary, mussel, mytilus chilensis, nonhuman, ph, physical chemistry, phytoplankton, priority journal, salinity, temperature, volcanic ash, volcano, water sampling, analysis, animal, body constitution, chemistry, chile, environmental monitoring, mytilus, physiology, season, calbuco volcano, los lagos, reloncavi fjord, mytilus edulis, animals, carbonates, seasons, seawater, volcanic eruptions
Ciudades Resilientes; Zonas Costeras2019Rowe, Penny M.; Cordero, Raul R.; Warren, Stephen G.; Stewart, Emily; Doherty, Sarah J.; Pankow, Alec; Schrempf, Michael; Casassa, Gino; Carrasco, Jorge; Pizarro, Jaime; MacDonell, Shelley; Damiani, Alessandro; Lambert, Fabrice; Rondanelli, Roberto; Huneeus, Nicolas; Fernandoy, Francisco; Neshyba, StevenBlack carbon and other light-absorbing impurities in snow in the Chilean AndesScientific Reports10.1038/s41598-019-39312-0Vertical profiles of black carbon (BC) and other light-absorbing impurities were measured in seasonal snow and permanent snowfields in the Chilean Andes during Austral winters 2015 and 2016, at 22 sites between latitudes 18°S and 41°S. The samples were analyzed for spectrally-resolved visible light absorption. For surface snow, the average mass mixing ratio of BC was 15 ng/g in northern Chile (18–33°S), 28 ng/g near Santiago (a major city near latitude 33°S, where urban pollution plays a significant role), and 13 ng/g in southern Chile (33–41°S). The regional average vertically-integrated loading of BC was 207 µg/m 2 in the north, 780 µg/m 2 near Santiago, and 2500 µg/m 2 in the south, where the snow season was longer and the snow was deeper. For samples collected at locations where there had been no new snowfall for a week or more, the BC concentration in surface snow was high (~10–100 ng/g) and the sub-surface snow was comparatively clean, indicating the dominance of dry deposition of BC. Mean albedo reductions due to light-absorbing impurities were 0.0150, 0.0160, and 0.0077 for snow grain radii of 100 µm for northern Chile, the region near Santiago, and southern Chile; respective mean radiative forcings for the winter months were 2.8, 1.4, and 0.6 W/m 2 . In northern Chile, our measurements indicate that light-absorption by impurities in snow was dominated by dust rather than BC. © 2019, The Author(s).http://www.nature.com/articles/s41598-019-39312-0vol.9.0 is.1.0Thomson Reuters ISI-
Agua y Extremos; Zonas Costeras; Transversal2019Rondanelli, R.; Hatchett, B.; Rutllant, J.; Bozkurt, D.; Garreaud, R.Strongest MJO on Record Triggers Extreme Atacama Rainfall and Warmth in AntarcticaGeophysical Research Letters10.1029/2018GL081475Tropical perturbations have been shown theoretically and observationally to excite long range atmospheric responses in the form of Rossby wave teleconnections that result from the equator to pole gradient of planetary vorticity. An extreme teleconnection event occurred during March 2015 in the Southeastern Pacific. As a result, extreme high temperatures were observed in Southwestern South America and the Antarctic Peninsula simultaneously with an extreme rainfall and flood event in the hyperarid Atacama desert.%%%%%%We show that the origin of these seemingly disconnected extreme events can be traced to a Rossby wave response to the strongest Madden‐Julian Oscillation (MJO) on record in the tropical central Pacific. A barotropic wavenumber 3 to 4 perturbation with group velocity between 15 to 30 m/s is consistent with the trajectory and timing followed by the upper level anomalies radiating away from the tropics after the MJO episode.https://onlinelibrary.wiley.com/doi/abs/10.1029/2018GL081475vol. is.Thomson Reuters ISIantarctica, atmospheric rivers, climate dynamics, extremes, flooding, rossby waves, flood control, floods, mechanical waves, oil well flooding, rain, tropics, antarctic peninsula, atmospheric response, madden-julian oscillation, rossby wave, rossby wave response, climatology, air-sea interaction, barotropic wave, climate change, extreme event, flood, high temperature, rainfall, teleconnection, wave velocity, atacama desert, chile, pacific ocean, pacific ocean (central), pacific ocean (southeast), south america, west antarctica
Zonas Costeras2019Bange, Hermann W.; Arévalo-Martínez, Damian L.; de la Paz, Mercedes; Farías, Laura; Kaiser, Jan; Kock, Annette; Law, Cliff S.; Rees, Andrew P.; Rehder, Gregor; Tortell, Philippe D.; Upstill-Goddard, Robert C.; Wilson, Samuel T.A Harmonized Nitrous Oxide (N2O) Ocean Observation Network for the 21st CenturyFrontiers in Marine Science10.3389/fmars.2019.00157Nitrous oxide (N2O) is an important atmospheric trace gas involved in tropospheric warming and stratospheric ozone depletion. Estimates of the global ocean contribution to N2O emissions average 21% (range: 10 to 53%). Ongoing environmental changes such as warming, deoxygenation and acidification are affecting oceanic N2O cycling and emissions to the atmosphere. International activities over the last decades aimed at improving estimates of global N2O emissions, including (i) the MarinE MethanE and NiTrous Oxide database (MEMENTO) for archiving of quality-controlled data, and (ii) a recent large-scale inter-laboratory comparison by Working Group 143 of the Scientific Committee on Ocean Research (SCOR). To reduce uncertainties in oceanic N2O emission estimates and to characterize the spatial and temporal variability in N2O distributions in a changing ocean, we propose the establishment of a harmonized N2O Observation Network (N2O-ON) combining discrete and continuous data from various platforms. The network will integrate observations obtained by calibrated techniques, using time series measurements at fixed stations and repeated hydrographic sections on voluntary observing ships and research vessels. In addition to exploiting existing oceanographic infrastructure, we propose the establishment of central calibration facilities in selected international laboratories to improve accuracy, and ensure standardization and comparability of N2O measurements. Final data products will include a harmonized global N2O concentration and emission fields for use in model validation and projections of future oceanic N2O emissions, to inform the global research community and policy makers.https://www.frontiersin.org/article/10.3389/fmars.2019.00157/full157vol.6.0 is.Thomson Reuters ISIcalibration, nitrous oxide, observation network, oceanic distribution, oceanic emissions
Zonas Costeras2019Imfeld, Noemi; Barreto Schuler, Christian; Correa Marrou, Kris Milagros; Jacques‐Coper, Martín; Sedlmeier, Katrin; Gubler, Stefanie; Huerta, Adrian; Brönnimann, StefanSummertime precipitation deficits in the southern Peruvian highlands since 1964International Journal of Climatology10.1002/joc.6087Precipitation deficits remain a concern to the rural population in the southern Peru-vian highlands and knowledge about their occurrence is lacking because of scarcedata availability. For mountainous regions with sparse station networks, reanalysescan provide valuable information; however, known limitations in reproducing pre-cipitation are aggravated due to unresolved topographical effects. In this study, weassess in a first step the representation of precipitation during the rainy season(January–February–March) in seven reanalysis data sets in comparison to a newlygenerated gridded precipitation data set for Peru. In a second step, we assess sum-mer precipitation deficits in Peru during the second half of the 20th century.In the reanalyses data sets, we find biases strongly influenced by the topography ofthe models and low correlations for the rainy season. Thus, reanalyses do not solvethe problem of data scarcity for this region either. Furthermore, we confirm that ElNiño is not a sufficient stratification criterion for precipitation deficits during therainy season (JFM) in the southern Peruvian highlands. Based on observationalrecords and reanalyses, a considerable fraction of inter-annual variability of precipi-tation can be explained through upper-tropospheric zonal wind anomalies. Westerlywind anomalies, often related to the warming of the troposphere during an El Niñoevent, lead to dry conditions, but not all El Niño events produce these westerly windanomalies. Atmospheric simulations indicate differences between precipitation defi-cits in central Pacific and eastern Pacific El Niño flavours, which cannot beaddressed in observations due to reduced record length: Droughts in the southernPeruvian Andes during eastern Pacific El Niño events seem to be related to a stron-ger warming in the troposphere above the central Pacific ocean, whereas this is notthe case for droughts during central Pacific El Niño events. These results, however,need to be further corroborated by model studies and palaeoclimatological research.https://onlinelibrary.wiley.com/doi/abs/10.1002/joc.6087joc.6087vol. is.Thomson Reuters ISIdrought, enso, era-20cm, mountain, peru, rainfall, reanalysis, spi, rain, topography, troposphere, atmospheric simulations, interannual variability, precipitation deficits, topographical effects, population statistics, annual variation, atmospheric modeling, data assimilation, el nino-southern oscillation, mountain region, precipitation (climatology), summer
Zonas Costeras2019Alarcón-Schumacher, Tomás; Guajardo-Leiva, Sergio; Antón, Josefa; Díez, BeatrizElucidating Viral Communities During a Phytoplankton Bloom on the West Antarctic PeninsulaFrontiers in Microbiology10.3389/fmicb.2019.01014In Antarctic coastal waters where nutrient limitations are low, viruses are expected to play a major role in the regulation of bloom events. Despite this, research in viral identification and dynamics is scarce, with limited information available for the Southern Ocean (SO). This study presents an integrative-omics approach, comparing variation in the viral and microbial active communities on two contrasting sample conditions from a diatom-dominated phytoplankton bloom occurring in Chile Bay in the West Antarctic Peninsula (WAP) in the summer of 2014. The known viral community, initially dominated by Myoviridae family (∼82% of the total assigned reads), changed to become dominated by Phycodnaviridae (∼90%), while viral activity was predominantly driven by dsDNA members of the Phycodnaviridae (∼50%) and diatom infecting ssRNA viruses (∼38%), becoming more significant as chlorophyll a increased. A genomic and phylogenetic characterization allowed the identification of a new viral lineage within the Myoviridae family. This new lineage of viruses infects Pseudoalteromonas and was dominant in the phage community. In addition, a new Phycodnavirus (PaV) was described, which is predicted to infect Phaeocystis antarctica, the main blooming haptophyte in the SO. This work was able to identify the changes in the main viral players during a bloom development and suggests that the changes observed in the virioplankton could be used as a model to understand the development and decay of blooms that occur throughout the WAP. © 2019 Alarcón-Schumacher, Guajardo-Leiva, Antón and Díez. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.https://www.frontiersin.org/article/10.3389/fmicb.2019.01014/full1014vol.10.0 is.Thomson Reuters ISIenvironmental genomics, phytoplankton blooms, southern ocean, viral ecology, viruses, capsid protein, chlorophyll a, dna polymerase, ribulosebisphosphate carboxylase, rna 16s, transcriptome, algal bloom, alteromonadales, antarctica, article, asfarviridae, bayes theorem, bootstrapping, chlorophyll content, cryptophyta, diatom, dna base composition, environmental factor, flavobacteriales, gammaproteobacteria, gene sequence, genetic correlation, genetic similarity, genome analysis, haptophyta, maximum likelihood method, metagenome, metagenomics, microbial community, monte carlo method, myoviridae, nonhuman, oxygen concentration, phycodnaviridae, phylogeny, population abundance, pseudoalteromonas phage pm2, quality control, rna sequence, rna virus, seasonal variation, single-stranded rna virus, siphoviridae, taxonomy, virus cell interaction, virus identification
Zonas Costeras2019Aparicio-Rizzo, Pilar; Masotti, ItaloInter-annual variability of oceanographic conditions and phytoplankton in Valparaíso Bay (~33°S), central ChileRevista de Biología Marina y Oceanografía10.22370/rbmo.2019.54.1.1495The inter-annual variability of oceanographic conditions and phytoplankton abundance and biomass was studied using 10 years (1986-1996) of in situ observations at a fixed station in Valparaíso Bay (~33ºS). The time series analysis revealed that strong S-SW winds drive a quasi-permanent upwelling activity that maintain the nutrients availability in the water column to fuel the phytoplankton in the bay. The most important changes in bio-oceanographic conditions were observed during 1987 El Niño event, which was characterized by higher temperatures but lower values for salinity, nitrate, and phosphate concentrations, together with a decrease of phytoplankton biomass compared to 1988 La Niña event when colder, saltier, and nutrient-rich upwelled water were observed. High Aconcagua River discharges were observed during the El Niño conditions (1987-1988 and 1993), which led to a decrease in surface salinity and a high abundance of dinoflagellates. Two periods with differences in bio-oceanographic conditions were observed; 1988-1992 showed lower temperatures but higher nutrients (nitrate), phytoplankton biomass and abundance of diatoms than 1993-1996 period. Throughout the study period, positive trends in upwelling activity was registered accompanied by a fall in phytoplankton biomass and dinoflagellate abundance. This paper provides new evidences concerning the influence of El Niño Southern Oscillation (ENSO) in phytoplankton and oceanographic conditions in the coastal upwelling off central Chile.https://revistas.uv.cl/index.php/rbmo/article/view/149570vol.54.0 is.1Thomson Reuters ISIaconcagua river, enso, phytoplankton, upwelling, valparaíso bay, abundance, annual variation, biomass, dinoflagellate, el nino-southern oscillation, environmental factor, surface temperature, time series analysis, chile, valparaiso bay, valparaiso chile, bacillariophyta, dinophyceae
Agua y Extremos; Zonas Costeras2019Garreaud, René D.; Boisier, Juan P.; Rondanelli, Roberto; Montecinos, Aldo; Sepúlveda, Hector H.; Veloso‐Aguila, DanielThe Central Chile Mega Drought (2010–2018): A climate dynamics perspectiveInternational Journal of Climatology10.1002/joc.6219Central Chile, home to more than 10 million inhabitants, has experienced an uninterrupted sequence of dry years since 2010 with mean rainfall deficits of 20–40%. The so‐called Mega Drought (MD) is the longest event on record and with few analogues in the last millennia. It encompasses a broad area, with detrimental effects on water availability, vegetation and forest fires that have scaled into social and economical impacts. Observations and reanalysis data reveal that the exceptional length of the MD results from the prevalence of a circulation dipole‐hindering the passage of extratropical storms over central Chile—characterized by deep tropospheric anticyclonic anomalies over the subtropical Pacific and cyclonic anomalies over the Amundsen–Bellingshausen Sea. El Niño Southern Oscillation (ENSO) is a major modulator of such dipole, but the MD has occurred mostly under ENSO‐neutral conditions, except for the winters of 2010 (La Niña) and 2015 (strong El Niño). Climate model simulations driven both with historical forcing (natural and anthropogenic) and observed global SST replicate the south Pacific dipole and capture part of the rainfall anomalies. Idealized numerical experiments suggest that most of the atmospheric anomalies emanate from the subtropical southwest Pacific, a region that has experienced a marked surface warming over the last decade. Such warming may excite atmospheric Rossby waves whose propagation intensifies the circulation pattern leading to dry conditions in central Chile. On the other hand, anthropogenic forcing (greenhouse gases concentration increase and stratospheric ozone depletion) and the associated positive trend of the Southern Annular Mode also contribute to the strength of the south Pacific dipole and hence to the intensity and longevity of the MD. Given the concomitance of the seemingly natural (ocean sourced) and anthropogenic forcing, we anticipate only a partial recovery of central Chile precipitation in the decades to come.https://onlinelibrary.wiley.com/doi/abs/10.1002/joc.6219joc.6219vol. is.Thomson Reuters ISIchile, climate change, drought, enso, pdo, sam, south america, atmospheric pressure, deforestation, greenhouse gases, mechanical waves, oceanography, ozone layer, rain, tropics, anthropogenic forcing, anticyclonic anomalies, climate model simulations, numerical experiments, stratospheric ozone depletion, climate models, antarctic oscillation, anthropogenic effect, atmospheric dynamics, climate forcing, el nino-southern oscillation, pacific decadal oscillation, precipitation (climatology), rossby wave, amundsen sea, bellingshausen sea, pacific ocean, pacific ocean (south), pacific ocean (subtropical), southern ocean
Agua y Extremos; Ciudades Resilientes; Gobernanza e Interfaz Ciencia y Política; Transversal; Zonas Costeras2019Bozkurt, Deniz; Rojas, Maisa; Boisier, Juan Pablo; Rondanelli, Roberto; Garreaud, René; Gallardo, LauraDynamical downscaling over the complex terrain of southwest South America: present climate conditions and added value analysisClimate Dynamics10.1007/s00382-019-04959-yThis study evaluates hindcast simulations performed with a regional climate model (RCM, RegCM4) driven by reanalysis data (ERA-Interim) over the Pacific coast and Andes Cordillera of extratropical South America. A nested domain configuration at \(0.44^{\circ }\) ( \(\sim\) 50 km) and \(0.09^{\circ }\) ( \(\sim\) 10 km) spatial resolutions is used for the simulations. RegCM4 is also driven by a global climate model (GCM, MPI-ESM-MR) on the same domain configuration to asses the added values for temperature and precipitation (historical simulations). Overall, both 10 km hindcast and historical simulation results are promising and exhibit a better representation of near-surface air temperature and precipitation variability compared to the 50 km simulations. High-resolution simulations suppress an overestimation of precipitation over the Andes Cordillera of northern Chile found with the 50 km simulations. The simulated daily temperature and precipitation extreme indices from 10 km hindcast simulation show a closer estimation of the observed fields. A persistent warm bias ( \(\sim +\,{4\,}^{\circ }\hbox {C}\) ) over the Atacama Desert in 10 km hindcast simulation reveals the complexity in representing land surface and radiative processes over the desert. Difficulties in capturing the temperature trend in northern Chile are notable for both hindcast simulations. Both resolutions exhibit added values for temperature and precipitation over large parts of Chile, in particular, the 10 km resolves the coastal-valley Andes transitions over central Chile. Our results highlight that resolutions coarser than 50 km (e.g., GCMs and reanalysis) miss important climate gradients imposed by complex topography. Given that the highest spatial resolution of the current regional simulations over the South America is about 50 km, higher resolutions are important to improve our understanding of the dynamical processes that determine climate over complex terrain and extreme environments.http://link.springer.com/10.1007/s00382-019-04959-yvol. is.Thomson Reuters ISIatacama desert, chile, climate variability, model evaluation, patagonia, temporal-spatial scale analysis, climate conditions, climate modeling, climate variation, complex terrain, downscaling, regional climate, spatial analysis, temporal analysis, andes, equus asinus
Gobernanza e Interfaz entre Ciencia y Política, Zonas Costeras2018Moraga, P., Delgado, V.
Sentencia Corte Suprema de 27 de agosto de 2018: Protección de Humedales Artificiales
Actualidad Jurídica Ambiental
La Junta de Vecinos Jardín Oriente 3, Agrupación Cultural por los Humedales y Entornos Naturales y la Sociedad Educacional Winkler Contreras (dueña del colegio Da Vinci), todos vecinos del sector denominado Jardín Oriente de la comuna de Puerto Montt dedujeron recurso de protección en contra de la Inmobiliaria GPR Puerto Varas Limitada (en adelante, “Inmobiliaria GPR”), Inmobiliaria Socovesa Sur S.A. (a continuación Socovesa) y el Servicio de Vivienda y Urbanismo de la Región de Los Lagos (en adelante SERVIU). El principal cuestionamiento es el proceder arbitrario e ilegal de la Inmobiliaria GPR que intervino el Humedal Llantén sin contar con los permisos sectoriales para realizar las obras. Lo anterior significó la modificación del cauce denominado “estero sin nombre”, como consecuencia del drenaje de las aguas del humedal, lo cual unido a las fuertes precipitaciones que afectan normalmente a la Región y el desborde de la piscina que administran las segundas recurridas causó diversas inundaciones que dañaron severamente los inmuebles cercanos y el colegio Da Vinci, que debió ser cerrado durante dichos episodios, además de la afectación del ecosistema del humedal. A su vez se señala que la Inmobiliaria Socovesa mantiene en terrenos de su propiedad, una piscina de retención de aguas lluvias para los conjuntos habitacionales que construyó en el sector y que es administrada por el Servicio de Vivienda y Urbanismo (SERVIU), la cual en periodos de fuertes lluvias sobrepasa su capacidad provocando el desborde de sus aguas y, posterior anegamientos de los terrenos colindantes. La Corte Suprema acoge la acción de protección y sostiene que el actuar de los recurridos se aparta de la normativa jurídica ambiental y urbanística y, por ende, lesiona las garantías constitucionales del derecho a la integridad física y psíquica de toda persona (art. 19 Nº 1) y la de vivir en un medio ambiente libre de contaminación (art. 19 Nº 8), en este caso, “respecto de los habitantes del sector Oriente de la comuna de Puerto Montt”, disponiéndose las siguientes medidas: a) La Municipalidad deberá revisar los permisos de construcción y recepciones de obras que autorizó a los recurridos, sobre la base que el sector cuenta con un humedal y por él pasa una vía fluvial que es parte de la red primaria del Sistemas de Evacuación y Drenaje de Aguas Lluvias. b) SERVIU deberá planificar, estudiar y fiscalizar el correcto funcionamiento de la piscina de retención de aguas lluvias, cuyo funcionamiento deberá mantener la Inmobiliaria Socovesa. d) Inmobiliaria GPR desplegará todas las medidas que sean necesarias para la protección del Humedal, mientras la Seremi del Medio Ambiente de la Región de Los Lagos estudia y revisa la situación en que se encuentra el mismo, con el fin de adoptar las providencias del caso. e) En el plazo de tres años el colegio deberá ser reubicado para despejar el área de escurrimiento natural de las aguas lluvias del sector.
http://www.actualidadjuridicaambiental.com/jurisprudencia-al-dia-iberoamerica-chile-humedales-artificiales/
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Zonas Costeras; Agua y Extremos2019Rivera, Diego; Gutierrez, Karen; Valdivia-Cea, Walter; Zambrano-Bigiarini, Mauricio; Godoy-Faúndez, Alex; Álvez, Amaya; Farías, LauraValidation of Cryogenic Vacuum Extraction of Pore Water from Volcanic Soils for Isotopic AnalysisWater10.3390/w11112214Andean headwater catchments are key components of the hydrological cycle, given that they capture moisture, store water and release it for Chilean cities, industry, agriculture, and cities in Chile. However, knowledge about within-Andean catchment processes is far from clear. Most soils in the Andes derive from volcanic ash Andosols and Arenosols presenting high organic matter, high-water retention capacity and fine pores; and are very dry during summer. Despite their importance, there is little research on the hillslope hydrology of Andosols. Environmental isotopes such as Deuterium and 18-O are direct tracers for water and useful on analyzing water-soil interactions. This work explores, for the first time, the efficiency of cryogenic vacuum extraction to remove water from two contrasting soil types (Arenosols, Andosols) at five soil water retention energies (from −1500 to −33 kPa). Two experiments were carried out to analyse the impact of extraction time, and initial water content on the amount of extracted water, while a third experiment tested whether the cryogenic vacuum extraction changed the isotopic ratios after extraction. Minimum extraction times to recover over 90% of water initially in the soil samples were 40–50 min and varied with soil texture. Minimum volume for very dry soils were 0.2 mL (loamy sand) and 1 mL (loam). After extraction, the difference between the isotope standard and the isotopic values after extraction was acceptable. Thus, we recommend this procedure for soils derived from volcanic ashes.https://www.mdpi.com/2073-4441/11/11/22142214vol.11.0 is.11Thomson Reuters ISIcryogenic vacuum extraction, isotopic analysis, volcanic soils, catchments, cryogenics, isotopes, runoff, soil moisture, textures, volcanoes, cryogenic vacuum, environmental isotopes, hillslope hydrology, initial water contents, soil water retention, water-soil interaction, extraction, catchment, deuterium, equipment component, extraction method, hillslope, soil water potential, tracer, volcanic ash, volcanic soil, water content, water retention, water-rock interaction, andes, chile
Zonas Costeras; Agua y Extremos; Gobernanza e Interfaz Ciencia y Política2019Aguirre, Catalina; Rojas, Maisa; Garreaud, René D.; Rahn, David A.Role of synoptic activity on projected changes in upwelling-favourable winds at the ocean’s eastern boundariesnpj Climate and Atmospheric Science10.1038/s41612-019-0101-9The climate of the ocean’s eastern boundaries is strongly influenced by subtropical anticyclones, which drive a surface wind stress that promotes coastal upwelling of nutrient-rich subsurface water that supports high primary productivity and an abundance of food resources. Understanding the projected response of upwelling-favourable winds to climate change has broad implications for coastal biogeochemistry, ecology, and fisheries. Here we use a reanalysis, an ensemble of global climate simulations, and an objective algorithm to track anticyclones to investigate the projected changes in upwelling-favourable wind events at the California, Canary, Humboldt, and Benguela coastal upwelling systems. Except for the north Pacific, we find consistent poleward shifts of mean and upper percentile daily winds over the ocean basins. We propose that extratropical, synoptic-scale migratory anticyclones that force intense coastal upwelling events—which become more frequent at higher latitudes and less frequent at lower latitudes in the future—play an important role in the projected changes in upwelling-favourable wind events in these coastal upwelling systems. These changes complement large-scale processes such as the poleward shift of the subtropical ridge (STR) and stationary subtropical highs. Hence, both extratropical and tropical processes need to be considered to fully explain projected changes at the coastal upwelling systems under anthropogenic climate change.http://www.nature.com/articles/s41612-019-0101-944vol.2.0 is.1Thomson Reuters ISI-
Zonas Costeras2019Alcorta, Jaime; Vergara-Barros, Pablo; Antonaru, Laura A.; Alcamán-Arias, María E.; Nürnberg, Dennis J.; Díez, BeatrizFischerella thermalis: a model organism to study thermophilic diazotrophy, photosynthesis and multicellularity in cyanobacteriaExtremophiles10.1007/s00792-019-01125-4The true-branching cyanobacterium Fischerella thermalis (also known as Mastigocladus laminosus) is widely distributed in hot springs around the world. Morphologically, it has been described as early as 1837. However, its taxonomic placement remains controversial. F. thermalis belongs to the same genus as mesophilic Fischerella species but forms a monophyletic clade of thermophilic Fischerella strains and sequences from hot springs. Their recent divergence from freshwater or soil true-branching species and the ongoing process of specialization inside the thermal gradient make them an interesting evolutionary model to study. F. thermalis is one of the most complex prokaryotes. It forms a cellular network in which the main trichome and branches exchange metabolites and regulators via septal junctions. This species can adapt to a variety of environmental conditions, with its photosynthetic apparatus remaining active in a temperature range from 15 to 58 °C. Together with its nitrogen-fxing ability, this allows it to dominate in hot spring microbial mats and contribute signifcantly to the de novo carbon and nitrogen input. Here, we review the current knowledge on the taxonomy and distribution of F.thermalis, its morphological complexity, and its physiological adaptations to an extreme environment.http://link.springer.com/10.1007/s00792-019-01125-4635-647vol.23.0 is.6Thomson Reuters ISIdistribution, fischerella, hot springs, mastigocladus, multicellularity, nitrogen fixation, photosynthesis, thermophile, acclimatization, biological model, cyanobacterium, evolution, heat, microbiology, physiology, thermal spring, trichome, biological evolution, cyanobacteria, hot temperature, models, biological, trichomes
Zonas Costeras2019Del Hoyo, Mirko; Rondanelli, Roberto; Escobar, RodrigoSignificant decrease of photovoltaic power production by aerosols. The case of Santiago de ChileRenewable Energy10.1016/j.renene.2019.10.005Santiago de Chile frequently suffers from atmospheric pollution that contributes to the decrease of solarirradiance on the surface, leading to losses in the energy output of photovoltaic systems. In this study, asimple model is used to estimate the effect of aerosols on the solar irradiance over the city throughoutthe year, using as input AERONET sunphotometer data and other in-situ measurements. The results showreductions of 3.5% and 14.1% for global horizontal and direct normal irradiance respectively and an in-crease of 35.4% for diffuse horizontal irradiance between the actual condition in Santiago and a hypo-thetical atmosphere free of aerosols. These effects translate approximately to an annual difference in theenergy output of 7.2% and 8.7% for monocrystalline and amorphous silicon PV technologies respec-tively, and an annual difference of 16.4% for a CPV technology, showing that aerosols can have a sig-nificant effect on the photovoltaic energy production.https://linkinghub.elsevier.com/retrieve/pii/S096014811931496XS096014811931496Xvol. is.Thomson Reuters ISIaeronet, aerosols, air pollution, chile, photovoltaics, santiago, solar irradiance, amorphous silicon, photovoltaic cells, photovoltaic effects, solar power generation, solar radiation, solar irradiances, aerosol, atmospheric pollution, data set, irradiance, photovoltaic system, silicon, metropolitana, santiago metropolitana
Zonas Costeras2020Ramírez, Paulina B.; Fuentes-Alburquenque, Sebastián; Díez, Beatriz; Vargas, Ignacio; Bonilla, Carlos A.Soil microbial community responses to labile organic carbon fractions in relation to soil type and land use along a climate gradientSoil Biology and Biochemistry10.1016/j.soilbio.2019.107692There has been a growing interest in studying the labile C pool in order to promote the sequestration and stabilization of soil organic carbon (SOC). Although labile SOC fractions have emerged as standardized indicators because of their potential to detect early SOC trends over time, the relationships between microbial attributes and labile SOC remains poorly understood. In this study, we explored the influence of labile SOC fractions on the topsoil bacteria-archaea community across 28 sites with different land use, climate aridity, and soil types across a wide range of SOC content (0.6–12%) in central Chile. We applied Illumina sequencing to the 16S rRNA to examine shifts in the diversity and composition of these soil microbial communities. Additionally, labile SOC fractions such as the permanganate oxidizable carbon (POXC) and light fraction organic matter (LFOM), along with the soil physicochemical properties were analyzed. The results demonstrated that among all of the environmental factors tested, the pH, POXC/SOC ratio and LFOM were key drivers of microbial community structure (β-diversity). The α-diversity metrics exhibited a decreasing trend when aridity increased, and community structure was found to vary, with high POXC/SOC in sites associated with drier conditions. In addition, POXC/SOC ratios and LFOM were clearly related to shifts in the relative abundances of specific taxonomic groups at genera level. When there was high POXC/SOC and low LFOM content, members of Bacteroidetes (Adhaeribacter, Flavisolibacter, and Niastella), Proteobacteria (Skermanella, Ramlibacter, and Sphingomonas), and Archaea (Thaumarchaeota) were found to be the most dominant groups; however, the microbial taxa responded differently to both labile C fraction types. These results have implications for understanding how labile C content can potentially be used to predict shifts in the microbial community, thus facilitating the development of predictive ecosystem models, as well as early warning indicators for soil degradation.https://linkinghub.elsevier.com/retrieve/pii/S0038071719303566107692vol.141.0 is.Thomson Reuters ISI16s rrna gene, archaea, bacterial diversity, light fraction, permanganate oxidizable carbon, soil ph, land use, microorganisms, organic carbon, physicochemical properties, rna, soils, stabilization, bacterium, climate change, community response, community structure, environmental factor, geodiversity, microbial activity, microbial community, odor, ph, relative abundance, soil carbon, soil microorganism, soil organic matter, soil type, species diversity, topsoil, chile, adhaeribacter, bacteria (microorganisms), bacteroidetes, niastella, proteobacteria, ramlibacter, skermanella, sphingomonas
Zonas Costeras2018Testa, Giovanni; Masotti, Italo; Farías, LauraTemporal Variability in Net Primary Production in an Upwelling Area off Central Chile (36°S)Frontiers in Marine Science10.3389/fmars.2018.00179The temporal variability of Net Primary Production (NPP) off central Chile (36°S, 73°W), an area subjected to seasonal coastal upwelling, was analyzed using monthly in situ 13C incubations within the photic zone, along with bio-oceanographic variables from a fixed time series station; and satellite NPP estimations (NPPE) from the Vertically Generalized Production Model between 2006 and 2015. NPP and NPPE rates varied from 0.03 to 18.29 and from 0.45 to 9.07 g C m−2 d−1, respectively. Both rates were fairly well correlated with each other (r2 = 0.61), but when these data were separated into two periods, higher r2 value was found during winter (r2 = 0.70) with respect to the rest of the year (r2 = 0.24); the latter correlation was partially due to increased weekly NPPE variability during active and relaxed upwelling events. NPP rates along with other biophysical variables allowed for a division of the annual cycle into three distinct periods: September to January (high productivity, mean integrated NPP rates of 4.0 g C m−2 d−1), February to March (intermediate productivity, mean integrated NPP rates of 1.4 g C m−2 d−1), and May to August (basal level, mean integrated NPP rates of 0.5 g C m−2 d−1). NPP appeared to be partially controlled by nutrient inputs, either from upwelling (September-April) and river discharge (May-August), maintaining high NPP rates throughout the entire year, with an annual mean NPP rate of 1.1 kg C m−2 yr−1. In this region, El Niño Southern Oscillation events did not appear to impact the NPP interannual variability.https://www.frontiersin.org/article/10.3389/fmars.2018.00179/fullvol.5.0 is.Thomson Reuters ISIcentral chile, coastal upwelling, el niño southern oscillation, primary production rates, river discharge
Zonas Costeras2018Troncoso, Macarena; Garcia, Gerardo; Verdugo, Josefa; Farías, LauraToward High-Resolution Vertical Measurements of Dissolved Greenhouse Gases (Nitrous Oxide and Methane) and Nutrients in the Eastern South PacificFrontiers in Marine Science10.3389/fmars.2018.00148In this study, in situ, real-time and high-resolution vertical measurements of dissolved greenhouse gases (GHGs) such as nitrous oxide (N2O) and methane (CH4) and nutrients are reported for the eastern South Pacific (ESP); a region with marked zonal gradients, ranging from highly productive and suboxic conditions in coastal upwelling systems to oligotrophic and oxygenated conditions in the subtropical gyre. Four high-resolution vertical profiles for gases (N2O and CH4) and nutrients (NO−3 and PO3−4) were measured using a Pumped Profiling System (PPS), connected with a liquid degassing membrane coupled with Cavity Ring-Down Spectroscopy (CRDS) and a nutrient auto-analyzer, respectively. The membrane-CRDS system maintains a linear response over a wide range of gas concentrations, detecting N2O and CH4 levels as low as 0.0774 ± 0.0004 and 0.1011 ± 0.001 ppm, respectively. Continuous profiles for gases and nutrients were similar to those reported throughout the ESP, with pronounced N2O and CH4 peaks at the upper oxycline and at the base of the euphotic zone and pycnocline, respectively, in the coastal zone; but almost constant depth profiles in the subtropical gyre. Additionally, other vertical gas and nutrient structures were observed using continuous sampling, which would not have been detected by discrete sampling. Our results demonstrate that continuous measurements can be a potentially useful methodology for future GHGs cycle studies.http://journal.frontiersin.org/article/10.3389/fmars.2018.00148/fullvol.5.0 is.Thomson Reuters ISIcontinuous profiles, eastern south pacific, methane, nitrous oxide, nutrients
Zonas Costeras2019Barrett, Bradford S.; Marin, Julio C.; Jacques-Coper, MartinA multiscale analysis of the tornadoes of 30–31 May 2019 in south-central ChileAtmospheric Research10.1016/j.atmosres.2019.104811On 30 and 31 May 2019, tornadoes occurred in the cities of Los Angeles and Talcahuano/Concepción in south-central Chile, in a region where tornado activity is not common. The main goal of this study was to analyze these tornadoes across multiple scales: synoptic, mesoscale, and subseasonal. On the synoptic scale, the tornadoes were associated with an anomalous 500-hPa trough and associated surface cyclone to the west of Chile. A strong (20+ m s−1) low-level jet accompanied this trough, potentially enhanced by flow blocking by the Andes. A relatively warm and saturated surface layer combined with cold upper-level temperatures in the trough to yield 200–500 J kg−1 of CAPE on both days. This CAPE was accompanied by high levels of both deep-layer and low-level shear. Storm motions inferred by lightning swaths and GOES-IR imagery, along with estimates of storm motion and updraft helicity from a high-resolution WRF simulation, suggested this CAPE-shear combination was sufficient for the tornadic thunderstorms to be supercells. Finally, anomalies of sea level pressure, 500-hPa height, and surface dew point temperature from 27 to 31 May 2019 resembled long-term composite anomalies for MJO phases 1 and 2, suggesting a subseasonal link between the extreme event in Chile and convection in the tropics.https://linkinghub.elsevier.com/retrieve/pii/S0169809519310683104811vol. is.Thomson Reuters ISIchile, mesoscale modeling, synoptic meteorology, tornadoes, sea level, storms, dewpoint temperature, meso-scale modeling, multi scale analysis, sea level pressure, tornadic thunderstorms, upper level temperatures, air temperature, atmospheric convection, cyclone, jet stream, mesoscale meteorology, thunderstorm, tornado, updraft, andes, bio bio, concepcion bio bio, los angeles bio bio, talcahuano
Zonas Costeras, Gobernanza e Interfaz entre Ciencia y Política, Ciudades Resilientes, Transversal2018Moraga, P., Farías, L., Delgado, V., Urquiza, A., Morales, B.Informe final Océano y NDCCR2 publicationEl Acuerdo de París sobre Cambio Climático establece como obligación para los países firmantes presentar una Contribución Nacionalmente Determinada (Nationally Determined Contributions, o NDCs) y revisarla cada cinco años. Es por esta razón que la NDC de Chile está siendo sometida a un proceso de revisión con el propósito de identificar oportunidades de actualización y refinamiento de su primera versión. El Ministerio de Relaciones Exteriores, responsable de llevar a cabo esta actualización, se ha propuesto incorporar la protección y conservación del océano en dicho proceso, en conformidad con los objetivos planteados en la declaración “Because the Ocean”, así como en el “Ocean Pathway Platform” lanzado por la Presidencia de la COP23. Para ello se estableció un marco de colaboración técnica entre el Ministerio de Relaciones Exteriores, el Centro de Ciencia del Clima y la Resiliencia (CR)2 y el Centro de Derecho Ambiental (CDA) de la Facultad de Derecho de la Universidad de Chile, entre los meses de diciembre de 2017 y abril de 2018, con el objeto de generar un informe sobre la incorporación del océano en la NDC de Chile, a la luz de la agenda oceánica y en concordancia con los Objetivos de Desarrollo Sustentable (ODS).https://www.cr2.cl/wp-content/uploads/2018/07/informe_oceano_NDC.pdfpublished onlineNot indexed
Ciudades Resilientes, Cambio de Uso de Suelo, Zonas Costeras, Agua y Extremos, Gobernanza e Interfaz entre Ciencia y Política, Transversal2019Gallardo, L., Rudnick, A., Barraza, J., Fleming, Z., Rojas, M., Gayó, E. M., Aguirre, C., Farías, L., Boisier, J. P., Garreaud, R., Barría, P., Miranda, A., Lara, A., Gómez-González, S., Arriagada, R. A.El Antropoceno en Chile: evidencias y formas de avanzarCR2 publicationEn el siglo XXI, el desarrollo de Chile está en juego debido a las amenazas planteadas por el Antropoceno. Esta época se caracteriza por la influencia humana sobre el sistema terrestre. Sin embargo, si se enfrenta con audacia, ofrece una oportunidad para un desarrollo sostenible. Independientemente de si hemos entrado en una nueva era geológica, el Antropoceno cuestiona nuestra forma de vivir en el planeta azul del sistema solar. O, dicho de otra manera, la forma de entender el progreso y el desarrollo. En un país con grandes desigualdades sociales, altamente vulnerable al cambio global, enfrentar este desafío es de crucial importancia y puede ofrecer nuevas oportunidades.https://www.cr2.cl/wp-content/uploads/2019/06/Informe-Antropoceno-castellano.pdfpublished onlineNot indexed
Zonas Costeras;Agua y Extremos;Gobernanza e Interfaz Ciencia y Política2019Rojas, M., Aldunce, P., Farias, L., González, H., Marquet, P., Muñoz, J. C., Palma-Behnke, R., Stehr, A., Vicuña, S.Evidencia científica y cambio climático en Chile. Resumen para tomadores de decisiones.CR2 publicationLos resúmenes están basados en los informes y los talleres del Comité Científico COP25, a los que contribuyeron investigadores de una red de más de 600 científicos de todas las disciplinas y regiones de Chile, primordialmente de universidades y centros de investigación académicos, pero también de institutos públicos y privados.https://www.cr2.cl/wp-content/uploads/2019/12/Evidencia-científica-y-cambio-climático-en-Chile.pdfpublished onlineNot indexed
Ciudades Resilientes;Zonas Costeras2019Farias, L., Ubilla, K., Aguirre, C., Bedriñana, L., Cienfugos, R., Delgado, V., Fernández, C., Fernández, M., Gaxiola, A., González, H., Hucke-Gaete, R., Marquet, P., Montencino, V., Morales, C., Narváez, D., Osses, M., Peceño, B., Quiroga, E., Ramajo, L., Sepúlveda, H. H., Soto, D., Vargas, E., Viddi, F., Valencia, J.Nueve medidas basadas en el océano para las Contribuciones Determinadas a nivel Nacional de ChileCR2 publicationLas Contribuciones Determinadas a nivel Nacional (NDC, por sus siglas en inglés) se han convertido en un instrumento clave para comprometer principalmente metas de mitigación y adaptación al cambio climático. Gestadas en el Acuerdo de París (2015) aspiran a cumplir dos de sus objetivos más ambiciosos: mantener el incremento de la temperatura global muy por debajo de los 2°C, respecto a la era preindustrial, y fortalecer y aumentar la capacidad de adaptación y resiliencia a los efectos adversos del cambio climático. La actualización de las NDC el año 2020 las llevará a convertirse en un instrumento ambicioso y con trazabilidad, luego de la declaración de limitar a 1.5 °C el incremento de temperatura al 2030 (IPCC, 2018) y la cumbre del clima de Katowice (COP24). Chile, ejerciendo la presidencia de la COP25, se debe comprometer a metas más ambiciosas, transparentes y progresivas, entre ellas, la carbono- neutralidad, la COP azul y la economía circular. La mesa Océanos del Comité Científico COP25, a partir de una metodología participativa y colaborativa, propone nueve medidas basadas en el océano, para contribuir a la meta de reducción de sus emisiones, y realiza un análisis de los alcances que tiene la primera propuesta de actualización de las NDC (2020) en el tema océano. Las medidas propuestas en este informe colindan con acciones que: 1) favorecen el secuestro de carbono, como soluciones basada en naturaleza (carbono azul); 2) reducen las emisiones de gases con efecto invernadero (GEI) en la economía del océano; y 3) abordan la vulnerabilidad, riesgos e impactos del cambio climático en el sector pesca y acuicultura, enfocándose en la inequidad social y de género, y la construcción de capacidades relativa a implementar un sistema observación del océano y reducir brechas en su conocimiento, gestión y administración. Se refuerza en el concepto de entierro de carbono como el resultado del funcionamiento a largo plazo de una compleja red de procesos del ciclo del carbono, donde los sedimentos marinos y suelos costeros se constituyen como el mayor reservorio de largo aliento de carbono en el planeta. Al respecto, se reúnen antecedentes de la ventaja competitiva que tiene Chile respecto a la protección de fondos marinos, marismas y bosques de algas pardas; ecosistemas de fundamental importancia para la mitigación del cambio climático, pero, específicamente, vulnerables a su impacto y a la acción humana. Respecto a la economía del océano, la reducción de la emisión de GEI por parte de actividades como el transporte marítimo, acuicultura y el uso de energías marinas son medidas muy factibles e internacionalmente comprobadas, cuyos costos-beneficios van en directa relación con los compromisos y mercados internacionales. Este es especialmente relevante para la acuicultura y la economía circular. Finalmente, para adaptarse deben existir capacidades en un Sistema Integrado de Observación del Océano Chileno (SIOOC) que incluya alertas ambientales tempranas y proyecciones, de modo de reducir riesgos y conflictividades ambientales y sociales, y disminuir las brechas de conocimiento, de gobernanza y económicas respecto al océano. Lo que importa es transformar los compromisos en acciones/medidas trazables, y al respecto, dada su vocación oceánica y su dependencia a este medio, Chile debe tener unas NDC ambiciosas que incluyan los hábitats y ecosistemas marinos (carbono azul) en los presupuestos de carbono nacional (además de las contribuciones en materia de cambio de uso de la tierra y silvicultura, UTCUTS), declarar co-beneficios, dar valoración económica de los servicios ecosistémicos ambientales, y formular políticas públicas dirigidas a la conservación. El presente informe releva la necesidad de generar voluntad política para fortalecer el marco normativo y/o legislativo que permita proteger a los sistemas costeros que cumplen importantes funciones para el cambio climático; fortalecer la capacidad adaptativa de las comunidades pesqueras y acuicultoras, y comprometer Áreas Marinas Protegidas con planes de manejo al corto plazo de modo de aumentar el nivel de ambición y alcanzar la carbono neutralidad.https://www.cr2.cl/wp-content/uploads/2019/12/Nueve-soluciones-para-NDC.pdfpublished onlineNot indexed
Zonas Costeras;Agua y Extremos2019Farias, L., Fernández, C., Garreaud, R., Guzmán, L., Hormazábal, S., Morales, C., Narváez, D., Pantoja, S., Pérez, I., Soto, D., Winckler, P.Propuesta de un Sistema Integrado de Observación del Océano ChilenoCR2 publicationChile ocupa el décimo puesto a nivel mundial con mayor territorio marítimo y el primer lugar en Latinoamérica con mayor superficie de mar. El país es dependiente del océano en términos económicos, sociales y culturales, que incluyen actividades en la zona costera y oceánica. Al mismo tiempo, los procesos climáticos y oceanográficos constituyen constantes fuentes de riesgo e incertidumbre, aumentando la vulnerabilidad en los socio-ecosistemas marinos. Chile está declarado un país altamente vulnerable al cambio climático, basado en estudios derivados de la Agenda 2030 para el Desarrollo Sostenible de las Naciones Unidas. Esto obliga a buscar propuestas y soluciones para abordar esta vulnerabilidad. A nivel internacional, varios países han desarrollado e implementado sistemas integrados de observación del océano basados en información continua sobre su estado y sus recursos, con el objetivo de abordar de forma operacional la vulnerabilidad. Estos sistemas de observación tienen propósitos, tales como, mejorar la seguridad en operaciones marinas, fortalecer la seguridad alimentaria, apoyar las actividades económicas de pequeña y gran escala, reducir el riesgo frente a desastres naturales y disminuir la incertidumbre económica junto con la conflictividad social y ambiental derivada de esta. El océano chileno está afecto a una serie de procesos globales asociados al cambio climático, regionales y locales que necesitan, ser estudiados y monitoreados. Por lo tanto, se requiere de la existencia de un sistema de registro continuo de variables atmosféricas y oceanográficas, que provea la información necesaria para la toma de decisiones, tanto públicas como privadas, y permita realizar análisis retrospectivos y predictivos del estado del océano. Actualmente, existen en Chile algunas iniciativas de observación y monitoreo del océano, incluyendo aportes de servicios públicos, instituciones académicas y organizaciones privadas. Sin embargo, estas no son sistémicas y carecen de continuidad, principalmente por falta de instrumentos financieros de largo aliento y de la valoración política de la información. En el compromiso nacional e internacional, el Comité Científico COP25 releva la importancia de contar con información basada en la evidencia para planificar estratégicamente el desarrollo sostenible y la equidad intergeneracional respecto del uso y la conservación del océano, de los ecosistemas marinos y sus servicios a la humanidad. En este escenario, académicos, servidores públicos y agentes del sector privado con competencia en la materia proponen gestar un Sistema Integrado de Observación del Océano Chileno (SIOOC), que permita disponer de datos de calidad, estandarizados y de acceso público para el estudio, monitoreo, manejo y vigilancia del océano y sus recursos. Se contemplan para la implementación del SIOOC, basado en la experiencia existente y las necesidades o brechas del Chile, tres fases en un horizonte de 6 a 8 años: › Primero, consolidar la integración de los sistemas existentes en una red asociativa y bajo una gobernanza apropiada, con recursos humanos y financiamiento de fuentes múltiples, e incluyendo la participación del sector privado, productivo y de la sociedad civil. › Segundo, incorporar al sistema de nuevos equipamientos e infraestructura (primario y secundario), con un análisis de las capacidades habilitantes y la transferencia tecnológica necesaria para aumentar el tipo, número y cobertura de las observaciones, además de fortalecer las capacidades de predicción. › Tercero, incorporar en pleno del SIOOC a otras redes internacionales, especialmente en zonas de alto interés, como la zona antártica, aguas internacionales e islas oceánicas. Las universidades y los servicios del Estado participantes en esta propuesta comprometen la infraestructura y los conocimientos existentes para dar lanzamiento al SIOOC. A su vez, esperan que el Estado tome esta iniciativa y un compromiso nacional e internacional como una acción para proteger nuestros mares.https://www.cr2.cl/wp-content/uploads/2019/12/Propuesta-de-sistema-integrado-de-observación-del-océano.pdfpublished onlineNot indexed
Zonas Costeras2019Farias, L., Acuña, E., Aguirre, C., Álvarez, S., Barbieri, M. A., Delgado, V., Dewitte, B., Espinoza, Ó., Fernández, C., Garrido, P., Jacob, B., Lagos, N., Masotti, I., Narváez, D., Navarrete, S., Pérez-Santos, I., Pinilla, E., Ramajo, L., Saavedra, L., Silva, C., Soto, D., Troncoso, L., Vargas, C. A., Veas, C., Winckler, P., Yañez, E., Yévenes, A.Propuesta para la actualización de Plan de Adaptación en Pesca y AcuiculturaCR2 publicationEl Plan de Adaptación al Cambio Climático en Pesca y Acuicultura (PACCPA) es un instrumento articulador que delinea acciones y medidas relativas a políticas públicas y gestión pesquera y acuícola, con el objetivo de fortalecer la capacidad de adaptación del sector al cambio climático. La Mesa Océanos del Comité Científico COP25 presenta esta propuesta para la actualización y mejoramiento del PACCPA a la luz de los cambios físicos, químicos y biológicos que afectan al océano, sean estos observados o proyectados; para la evaluación de diferentes tipos de riesgos en la zona costera y otros antecedentes socioeconómicos, jurídicos, normativos y de gobernanza que impactan positiva o negativamente sobre la actividad pesquera y acuícola. El presente documento entrega observaciones y argumentos relativos a los 5 objetivos específicos y 29 acciones delineadas en el primer PACCPA (2015-2020); además, introduce 16 nuevas acciones asociadas a tres de los objetivos ya planteados y agrega dos nuevos objetivos específicos relativos a fomentar e incentivar la economía circular y fortalecer el rol de la mujer, para una mejor adaptación de las comunidades costeras. Se introducen los nuevos antecedentes de: gobernanza climática internacional, en los cuales Chile tiene compromisos, institucionalidad nacional y del marco normativo y jurídico con el cual administra y gestiona los recursos marinos y la zona costera. Se releva la necesidad de reformar el concepto de enfoque ecosistémico y principio precautorio de la Ley de Pesca y Acuicultura en un contexto de cambio climático y, explícitamente, de incorporar la actividad acuícola bajo estos conceptos. Existe consenso de que la armonización de las estructuras de gobernanza local y/o macrozonas proporcionarán una política general de acción y asignación de recursos necesarios para la adaptación. Se analizan, además, los procesos y las variables oceanográficas y climáticas que afectan a las pesquerías y a la acuicultura (no todas consideradas en el primer PACCPA), como acidificación, desoxigenación, estratificación, aumento de la intensidad de la surgencia y de la frecuencia de eventos El Niño, entre otros, además de riesgos e impactos del aumento del nivel del mar y marejadas para el sector. Se resalta la necesidad de profundizar en el conocimiento de parámetros biológicos relacionados con la reproducción, la alimentación y la sobrevivencia de los recursos pesqueros y de cultivo a diferentes edades. Con el análisis de planes existentes y nuevas evidencias, se levantaron brechas de conocimiento, gobernanza, ambientales y socioeconómicas; estas últimas importantes de ponderar, pues los trabajadores de este sector son los que reciben los más bajos ingresos, poseen un menor nivel de educación y de salud y, por ello, son más vulnerables. En este contexto, el cambio climático profundiza las desigualdades y es un multiplicador de amenazas. Se indica que muchas variables/procesos que afectan a los recursos biológicos (amenazas) no deben ser analizados individualmente, sino como multi-amenazas, debido a la correlación que existe entre ellos; asimismo, se debe realizar un fortalecimiento institucional, sistematizar y profundizar el conocimiento científico. Relativo a esto último, se repite una y otra vez la necesidad de un Sistema Integrado de Observación del Océano Chileno (SIOOC) y el uso y mejoramiento de modelos regionales propios; donde se acoplen modelos oceanográficos con los pesqueros con fines de predicción y comprensión de los mecanismos que entran en juego, entre los recursos pesqueros y el efecto antrópico (como la sobrepesca), separando así la variabilidad ambiental del cambio climático y la capacidad de adaptación. Respecto a la acuicultura, también se requiere por una parte una evaluación profunda y analítica del impacto a nivel macro y microbiológico que ejercen los centros de cultivo sobre su entorno y cómo estos pueden exacerbar la crisis climática en curso; además de cuantificar cómo los efectos del cambio climático (aumento de temperatura, cambios en corrientes, acidificación, salinidad, oxigenación, etc.) impactan la sostenibilidad y productividad del sector. Finalmente, se concluye y recomienda que es vital incluir los aspectos socioeconómicos, de gobernanza y financiamiento al nuevo PACCPA, considerando la diversidad de amenazas, pero también las oportunidades que se presentan para el sectorhttps://www.cr2.cl/wp-content/uploads/2019/12/Propuesta-de-actualización-para-Plan-de-Adaptación.pdfpublished onlineNot indexed
Zonas Costeras2018Masotti, Italo; Aparicio-Rizzo, Pilar; Yevenes, Mariela A; Garreaud, Rene; Farias, LauraThe influence of river discharge on nutrient export and phytoplankton biomass off the Central Chile coast (33º-37ºS). Seasonal cycle and interannual variabilityFrontier in Marine Science10.3389/fmars.2018.00423Using in situ hydro-chemical data and MODIS-SeaWiFS ocean color images as a proxy of river plumes and phytoplankton biomass from 2000 to 2014, this study documents the temporal co-variability of river discharge, plume area, nitrate and phosphate export and phytoplankton biomass in the coastal waters off Central Chile (33º-37ºS). Five major rivers (Maipo, Mataquito, Maule, Itata and Biobío) drain into this region with annual mean discharge ranging from 120 to 1000 m3 s-1. River discharge and coastal plume area present a marked seasonal cycle, reaching maximum values during the winter rainy season (June-September). Export of riverine nutrients also peaks in winter, leading to an increase in phytoplankton biomass within the plumes that can be twice larger than the background values in coastal areas away from the river mouths. Wintertime river discharge, plume area and nutrient export are also correlated at interannual time scales. During a recent extended dry period (2010-2014), river discharges, plume areas and nutrient export clearly decreased by about 50% compared to historical values, reducing significantly the size of the chlorophyll pool within plumes off Central Chile during winter. The potential impacts of droughts are discussed in terms of coastal ecology and primary production, a highly relevant issue considering the projections of a dry climate over Central Chile in the future. Systematic evidence of mega-drought effects upon coastal productivity still does not exist, but it remains a priority to further investigate and quantify these impacts.27vol. is.Thomson Reuters ISIcentral chile, drought, nutrient export, phytoplankton biomass, river discharge, satellite remote sensing
Zonas Costeras2018Masotti, Italo; Aparicio-Rizzo, Pilar; Yevenes, Mariela A; Garreaud, Rene; Farias, LauraThe influence of river discharge on nutrient export and phytoplankton biomass off the Central Chile coast (33º-37ºS). Seasonal cycle and interannual variabilityFrontier in Marine Science10.3389/fmars.2018.00423Using in situ hydro-chemical data and MODIS-SeaWiFS ocean color images as a proxy of river plumes and phytoplankton biomass from 2000 to 2014, this study documents the temporal co-variability of river discharge, plume area, nitrate and phosphate export and phytoplankton biomass in the coastal waters off Central Chile (33º-37ºS). Five major rivers (Maipo, Mataquito, Maule, Itata and Biobío) drain into this region with annual mean discharge ranging from 120 to 1000 m3 s-1. River discharge and coastal plume area present a marked seasonal cycle, reaching maximum values during the winter rainy season (June-September). Export of riverine nutrients also peaks in winter, leading to an increase in phytoplankton biomass within the plumes that can be twice larger than the background values in coastal areas away from the river mouths. Wintertime river discharge, plume area and nutrient export are also correlated at interannual time scales. During a recent extended dry period (2010-2014), river discharges, plume areas and nutrient export clearly decreased by about 50% compared to historical values, reducing significantly the size of the chlorophyll pool within plumes off Central Chile during winter. The potential impacts of droughts are discussed in terms of coastal ecology and primary production, a highly relevant issue considering the projections of a dry climate over Central Chile in the future. Systematic evidence of mega-drought effects upon coastal productivity still does not exist, but it remains a priority to further investigate and quantify these impacts.27vol. is.Thomson Reuters ISIcentral chile, drought, nutrient export, phytoplankton biomass, river discharge, satellite remote sensing
Zonas Costeras;Gobernanza e Interfaz entre Ciencia y Política2019Farias, L.; Aguilera, V.; Aguirre, C.; Barbieri, M. A.; Castillo-Silva, M.; Contreras-López, M.; Dewitte, B.; Echeveste, P.; Fernández, C.; Gómez-Canchong, P.; Lagos, N. A.; Lara, L. E.; Marquet, P.; Miquel, J. C.; Molina, M.; Montecino, V.; Morales, M. C.; Narváez, D.; Navarrete, S.; Oliveros-Clavijo, V.; Quiroga, E.; Ramajo, L.; Rojas, M.; Saavedra, L.; Salinas, X.; Silva, C.; Urbina, M.; Vargas, C.; Vidal, G.; von Dassow, P.; Winckler, P.; Yañez, E.Océano y Cambio Climático. 50 preguntas y respuestasCR2 publicationTodos los que habitamos el planeta dependemos directa o indirectamente del océano. Este provee alimento, transporte, cultura y, a través del intercambio de agua, energía y carbono; asimismo, es sustento de hábitats únicos que han sido dañados progresivamente por los efectos del cambio climático. A nivel global 680 millones de personas habitan zonas costeras. En Chile, nuestra relación es todavía más estrecha. Debido a nuestra extensa geografía, un cuarto de la población se distribuye en 100 comunas costeras donde más de 500 caletas dan sustento a 90 mil trabajadores vinculados a la pesca artesanal. La creciente y cada vez más contundente evidencia científica sobre el impacto del cambio climático en los ecosistemas marinos revela la vulnerabilidad a la que se exponen los habitantes y otros seres vivos de estos territorios, y, por lo mismo, es un llamado urgente que nos moviliza a la acción. Como Ministerio de Ciencia, Tecnología, Conocimiento e Innovación trabajamos activamente con la comunidad científica para utilizar la evidencia en el diseño de políticas que nos permitan sobreponernos y anticiparnos a los efectos del cambio climático. En esta búsqueda, y con motivo de la cumbre de acción climática COP25, hemos impulsado la organización del Comité Científico que reúne a más de 550 investigadores nacionales del cambio climático. Este trabajo busca contribuir directamente al tránsito que necesitamos desde la evidencia a la acción climática ambiciosa y factible. Las siguientes páginas son el resultado del esfuerzo colectivo de los investigadores e investigadoras de la mesa Océanos de este comité. Este documento es un aporte al debate ciudadano y a la necesaria sensibilización sobre la importancia de nuestro océano. Solo si logramos comprender en profundidad procesos como el aumento del nivel del mar, sus cambios de temperatura, acidificación, oxigenación, eventos extremos asociados al océano y la pérdida de biodiversidad que enfrenta, podremos impulsar medidas de adaptación y mitigación que apunten a un desarrollo sostenible e integral en beneficio de las personas y el medioambiente que lo permite.https://www.cr2.cl/wp-content/uploads/2019/10/El-ABC-del-Océano-y-el-cambio-Cimático.pdfpublished onlineNot indexed
Zonas Costeras2020Aguirre, R., Toledo, F., Rodríguez, R., Rondanelli, R., Reyes, N., Díaz, M.Low-Cost Ka-Band Cloud Radar System for Distributed Measurements within the Atmospheric Boundary LayerRemote Sensing of Environment10.3390/rs12233965Radars are used to retrieve physical parameters related to clouds and fog. With these measurements, models can be developed for several application fields such as climate, agriculture, aviation, energy, and astronomy. In Chile, coastal fog and low marine stratus intersect the coastal topography, forming a thick fog essential to sustain coastal ecosystems. This phenomenon motivates the development of cloud radars to boost scientific research. In this article, we present the design of a Ka-band cloud radar and the experiments that prove its operation. The radar uses a frequency-modulated continuous-wave with a carrier frequency of 38 GHz. By using a drone and a commercial Lidar, we were able to verify that the radar can measure reflectivities in the order of −60 dBZ at 500 m of distance, with a range resolution of 20 m. The lower needed range coverage imposed by our case of study enabled a significant reduction of the instrument cost compared to existent alternatives. The portability and low-cost of the designed instrument enable its implementation in a distributed manner along the coastal mountain range, as well as its use in medium-size aerial vehicles or balloons to study higher layers. The main features, limitations, and possible improvements to the current instrument are discussed. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097032032&doi=10.3390%2frs12233965&partnerID=40&md5=3dd8fd830d746112562ece834e0aa51b396512Thomson Reuters ISIBoundary layer; Cloud radar; Frequency modulated continuous wave radar; Ka-band radar
Zonas Costeras2020Alcorta, J., Alarcón-Schumacher, T., Salgado, O., Díez, B.Taxonomic Novelty and Distinctive Genomic Features of Hot Spring CyanobacteriaClimate Dynamics10.3389/fgene.2020.568223Several cyanobacterial species are dominant primary producers in hot spring microbial mats. To date, hot spring cyanobacterial taxonomy, as well as the evolution of their genomic adaptations to high temperatures, are poorly understood, with genomic information currently available for only a few dominant genera, including Fischerella and Synechococcus. To address this knowledge gap, the present study expands the genomic landscape of hot spring cyanobacteria and traces the phylum-wide genomic consequences of evolution in high temperature environments. From 21 globally distributed hot spring metagenomes, with temperatures between 32 and 75°C, 57 medium- and high-quality cyanobacterial metagenome-assembled genomes were recovered, representing taxonomic novelty for 1 order, 3 families, 15 genera and 36 species. Comparative genomics of 93 hot spring genomes (including the 57 metagenome-assembled genomes) and 66 non-thermal genomes, showed that the former have smaller genomes and a higher GC content, as well as shorter proteins that are more hydrophilic and basic, when compared to the non-thermal genomes. Additionally, the core accessory orthogroups from the hot spring genomes of some genera had a greater abundance of functional categories, such as inorganic ion metabolism, translation and post-translational modifications. Moreover, hot spring genomes showed increased abundances of inorganic ion transport and amino acid metabolism, as well as less replication and transcription functions in the protein coding sequences. Furthermore, they showed a higher dependence on the CRISPR-Cas defense system against exogenous nucleic acids, and a reduction in secondary metabolism biosynthetic gene clusters. This suggests differences in the cyanobacterial response to environment-specific microbial communities. This phylum-wide study provides new insights into cyanobacterial genomic adaptations to a specific niche where they are dominant, which could be essential to trace bacterial evolution pathways in a warmer world, such as the current global warming scenario. © Copyright © 2020 Alcorta, Alarcón-Schumacher, Salgado and Díez.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85096368421&doi=10.3389%2ffgene.2020.568223&partnerID=40&md5=49af664f6707655b03e747ab4c48921956822311Thomson Reuters ISIcyanobacteria; hot springs; MAGs; metagenomes; taxonomy; thermophiles
Zonas Costeras2020Aparicio-Rizzo, P., Masotti, I., Landaeta, Mauricio F.Influence of coastal upwelling on micro-phytoplankton variability at Valparaíso Bay (~33ºS), Central ChileApplied Vegetation Science10.22370/rbmo.2020.55.1.2353In this work 10 years of data (1986-1996) from a fixed station located in the northern part of Valparaíso Bay (33°00’S; 71°35’W) were analysed to study the influence of coastal upwelling activity on the temporal variation of micro-phytoplankton (20-200 μm) and their relationship with oceanographic conditions. The upwelling activity at the bay was associated to semi-annual wind regime with an intensification of upwelling-favourable S-SW winds from September to March followed by a decrease and the occurrence of downwelling events from April to August. Oceanographic conditions showed the ascent of cold, nutrient-rich salty water in spring (September-November). However, during summertime under highest upwelling index, thermal stratification conditions were registered. This stratification might be associated to either the solar radiation or the presence of an upwelling shadow area in the bay. The upwelling period had the highest micro-phytoplankton abundance mainly dominated by diatoms. This period was associated with an increase in biomass and richness in the bay. Meanwhile during non-upwelling period —under homogenous conditions of temperature, salinity and nutrients— an increase in diversity (but low abundance and richness) associated to dinoflagellates and silicoflagellates was noted. Therefore, the results suggest the presence of a bi-modal regime of micro-phytoplankton in the bay in response to changes in oceanographic conditions related to local wind forcing and mixing/stratification. © 2020, Universidad De Valparaíso, Chile. All rights reserved.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089592593&doi=10.22370%2frbmo.2020.55.1.2353&partnerID=40&md5=8fe66bb1d3624289c1e55801a559d2cf1155Thomson Reuters ISIMicro-phytoplankton; Stratification; Upwelling; Valparaíso Bay; Wind
Zonas Costeras2018Arroyo, José I., Nery, Mariana F.Gene fusion of heterophyletic gamma-globin genes in platyrrhine primatesWater10.1007/s12041-018-1039-0We performed phylogenetic analyses of HBG genes to assess its origin and interspecific variation among primates. Our analyses showed variation in HBG genes copy number ranging from one to three, some of them pseudogenes. For platyrrhines HBG genes, phylogenetic reconstructions of flanking regions recovered orthologous clades with distinct topologies for 5′ and 3′ flanking regions. The 5′ region originated in the common ancestor of platyrrhines but the 3′ region had an anthropoid origin. We hypothesize that the platyrrhine HBG genes of 5′ and 3′ heterophyletic origins arose from subsequent fusions of the (earlier) platyrrhine 5′ portion and the (later) anthropoid 3′ portion. © 2018, Indian Academy of Sciences.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85057108851&doi=10.1007%2fs12041-018-1039-0&partnerID=40&md5=4c533ee9e1587550fd32533652f2ecef1473-147897Thomson Reuters ISIgene conversion; gene duplication; gene fusion; globins; primates; recombination
Zonas Costeras2020Bayer, S., Beierlein, L., Morán, Gisela A., Doldán, María S., Morsan, Enrique M., Brey, T., Mackensen, A., Farias, L., García, G., Gordillo, SLate Quaternary climatic variability in northern Patagonia, Argentina, based on δ18O of modern and fossil shells of Amiantis purpurata (Bivalvia, Veneridae)Inverse Problems10.1016/j.palaeo.2020.110012Amiantis purpurata is a common warm-temperate water bivalve species distributed from southern Brazil to northern Patagonia, Argentina, which has a rich and well preserved fossil record in the San Matías Gulf (SMG) dating back to the late Quaternary. This study aims to establish A. purpurata shells as a new palaeoarchive of past marine conditions in South America. We compared the stable oxygen and carbon profiles (δ18Oshell; δ13Cshell) of eleven specimens of A. purpurata from different geological times (modern, Late Holocene and interglacial Late Pleistocene), and additionally present in situ oxygen isotope values of seawater within SMG (δ18Owater). Using both sets of information, we calculated and reconstructed palaeowater temperatures for the Late Holocene and compared them to modern water temperatures. Our findings indicate that A. purpurata records past environmental parameters such as water temperatures on a seasonal scale and can therefore be considered a suitable candidate for future palaeoenvironmental reconstructions in Northern Patagonia. This study is the first step towards further stable isotope analyses on fossil A. purpurata shells, which will show whether and if so, to what extent, important global climate events such as the Neoglacial (Early Holocene), the Hypsithermal (Middle Holocene) and the Little Ice Age (Late Holocene) occurred in South America. © 2020 Elsevier B.V.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85095420602&doi=10.1016%2fj.palaeo.2020.110012&partnerID=40&md5=c1c01756dae4fad660b8ad0d57bb2176110012560Thomson Reuters ISIHolocene; Oxygen isotopes; Palaeoarchives; Palaeotemperatures; Pleistocene; Seasonality
Zonas Costeras;Agua y Extremos2020Bozkurt, D., Bromwich, David H., Carrasco, J., Hines, Keith M., Maureira, Juan C., Rondanelli, RRecent Near-surface Temperature Trends in the Antarctic Peninsula from Observed, Reanalysis and Regional Climate Model DataAtmospheric Chemistry and Physics10.1007/s00376-020-9183-xThis study investigates the recent near-surface temperature trends over the Antarctic Peninsula. We make use of available surface observations, ECMWF’s ERA5 and its predecessor ERA-Interim, as well as numerical simulations, allowing us to contrast different data sources. We use hindcast simulations performed with Polar-WRF over the Antarctic Peninsula on a nested domain configuration at 45 km (PWRF-45) and 15 km (PWRF-15) spatial resolutions for the period 1991-2015. In addition, we include hindcast simulations of KNMI-RACMO21P obtained from the CORDEX-Antarctica domain (~50 km) for further comparisons. Results show that there is a marked windward warming trend except during summer. This windward warming trend is particularly notable in the autumn season and likely to be associated with the recent deepening of the Amundsen/Bellingshausen Sea low and warm advection towards the Antarctic Peninsula. On the other hand, an overall summer cooling is characterized by the strengthening of the Weddell Sea low as well as an anticyclonic trend over the Amundsen Sea accompanied by northward winds. The persistent cooling trend observed at the Larsen Ice Shelf station is not captured by ERA-Interim, whereas hindcast simulations indicate that there is a clear pattern of windward warming and leeward cooling. Furthermore, larger temporal correlations and lower differences exhibited by PWRF-15 illustrate the existence of the added value in the higher spatial resolution simulation. © 2020, The Author(s).https://www.scopus.com/inward/record.uri?eid=2-s2.0-85083200583&doi=10.1007%2fs00376-020-9183-x&partnerID=40&md5=ee082b08745c0a2baf13646b4a166bd5477-49337Thomson Reuters ISIadded value; Amundsen/Bellingshausen Sea; cloud computing; dynamical downscaling; reanalysis; temperature trend; Weddell Sea; 宋米荣
Agua y Extremos;Zonas Costeras2020Damiani, A., Cordero, Raul R., Llanillo, Pedro J., Feron, S., Boisier, Juan P., Garreaud, R., Rondanelli, R., Irie, H., Watanabe, SConnection between Antarctic Ozone and Climate: Interannual Precipitation Changes in the Southern HemisphereAir Quality, Atmosphere & Health10.3390/atmos11060579In this study, we explored the connection between anomalies in springtime Antarctic ozone and all-year precipitation in the Southern Hemisphere by using observations from 1960-2018 and coupled simulations for 1960-2050. The observations showed that this correlation was enhanced during the last several decades, when a simultaneously increased coupling between ozone and Southern Annular Mode (SAM) anomalies became broader, covering most of the following summer and part of the previous winter. For eastern Australia, the ozone-precipitation connection shows a greater persistence toward the following summer than for other regions. On the other hand, for South America, the ozone-precipitation correlation seems more robust, especially in the early summer. There, the correlation also covers part of the previous winter, suggesting that winter planetary waves could affect both parameters. Further, we estimated the sensitivity of precipitation to changes in Antarctic ozone. In both observations and simulations, we found comparable sensitivity values during the spring-summer period. Overall, our results indicate that ozone anomalies can be understood as a tracer of stratospheric circulation. However, simulations indicate that stratospheric ozone chemistry still contributes to strengthening the interannual relationship between ozone and surface climate. Because simulations reproduced most of the observed connections, we suggest that including ozone variability in seasonal forecasting systems can potentially improve predictions. © 2020 by the authors.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087109591&doi=10.3390%2fatmos11060579&partnerID=40&md5=8a07b54f54f78182c3b0fb5b44c5bf8e57911Thomson Reuters ISIClimate; Ozone hole; Precipitation
Zonas Costeras;Gobernanza e Interfaz Ciencia y Política2020Flores-Aqueveque, V., Rojas, M., Aguirre, C., Arias, Paola A., González, CSouth Pacific Subtropical High from the late Holocene to the end of the 21st century: insights from climate proxies and general circulation modelsEnvironmental Research Letters10.5194/cp-16-79-2020The South Pacific Subtropical High (SPSH) is a predominant feature of the South American climate. The variability of this high-pressure center induces changes in the intensity of coastal alongshore winds and precipitation, among others, over southwestern South America. In recent decades, strengthening and expansion of the SPSH have been observed and attributed to the current global warming. These changes have led to an intensification of the southerly winds along the coast of northern to central Chile and a decrease in precipitation from central to southern Chile. Motivated by improving our understanding about the regional impacts of climate change in this part of the Southern Hemisphere, we analyzed SPSH changes during the two most extreme climate events of the last millennium, the Little Ice Age (LIA) and the Current Warm Period (CWP: 1970-2000), based on paleoclimate records and CMIP5/PMIP3 model simulations. In order to assess the level of agreement of general circulation models, we also compare them with ERA-Interim reanalysis data for the 1979-2009 period as a complementary analysis. Finally, with the aim of evaluating future SPSH behavior, we include 21st century projections under a Representative Concentration Pathway (RCP8.5) scenario in our analyses. Our results indicate that during the relative warm (cold) period, the SPSH expands (contracts). Together with this change, alongshore winds intensify (weaken) south (north) of ∼ 35° S; also, southern westerly winds become stronger (weaker) and shift southward (northward). Model results generally underestimate reanalysis data. These changes are in good agreement with paleoclimate records, which suggest that these variations could be related to tropical climate dynamics but also to extratropical phenomena. However, although models adequately represent most of the South American climate changes, they fail to represent the Intertropical Convergence Zone-Hadley cell system dynamics, emphasizing the importance of improving tropical system dynamics in simulations for a better understanding of its effects on South America. Climate model projections indicate that changes recently observed will continue during the next decades, highlighting the need to establish effective mitigation and adaptation strategies against their environmental and socioeconomic impacts. © Author(s) 2020.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078052563&doi=10.5194%2fcp-16-79-2020&partnerID=40&md5=fe080b38a9df7f9636d7e835353e57e879-9916Thomson Reuters ISI
Agua y Extremos;Zonas Costeras2020González-Reyes, Á., Jacques-Coper, M., Muñoz, Ariel ASeasonal precipitation in South Central Chile: trends in extreme events since 1900Viruses10.20937/ATM.52871Thomson Reuters ISI
Zonas Costeras2020Winckler-Grez, P., Aguirre, C., Farías, L., Contreras-López, M., Masotti, ÍEvidence of climate-driven changes on atmospheric, hydrological, and oceanographic variables along the Chilean coastal zoneSustainability10.1007/s10584-020-02805-3The Chilean coastal zone (CCZ) is subjected to a complex spectrum of anthropogenic, geophysical, biogeochemical, and climate-driven perturbations. Potentially affected variables including atmospheric sea level pressure (Pa), alongshore wind, sea surface temperature (SST), chlorophyll-a, rainfall, river discharge, relative mean sea level (RMSL), and wave climate are studied using in situ and satellite records, hindcasts, and reanalysis datasets. Linear temporal trends and correlations of anomalies are estimated between 18°S and 55°S along the CCZ. The comparison of some of the variables is achieved by means of a strict homogenization procedure on a monthly basis for 35 years. Our findings show that the poleward drift and strengthening of the Southeast Pacific Subtropical Anticyclone (SPSA) partially explains the increase in Pa and reduction in rainfall and river discharge. The enhancement of alongshore winds, also attributable to changes in the SPSA, increases coastal upwelling, which in turn could reduce SST and increase chlorophyll-a. Despite differential latitudinal responses, increasing wave heights and a southward rotation are evidenced. RMSL does not show significant variation as it is presumably affected by seafloor changes during the seismic cycle. Though some correlations are evidenced, the influence of climate variability at decadal scale (PDO, SAM) may be affecting the detected trends due to the short length of available data. Impacts on coastal communities, infrastructure, and ecosystems are discussed, aiming to highlight that coastal vulnerabilities and risk management should be based on the cumulative impacts of these variables. © 2020, The Author(s).https://www.scopus.com/inward/record.uri?eid=2-s2.0-85095683504&doi=10.1007%2fs10584-020-02805-3&partnerID=40&md5=7324a28fcc4a1871dc217258c816af67Thomson Reuters ISIClimate change; Coastal processes; Decadal trends
Zonas Costeras2020Guajardo-Leiva, S., Chnaiderman, J., Gaggero, A., Díez, B.Metagenomic Insights into the Sewage RNA Virosphere of a Large CityInternational Journal of Climatology10.3390/v12091050Sewage-associated viruses can cause several human and animal diseases, such as gastroenteritis, hepatitis, and respiratory infections. Therefore, their detection in wastewater can reflect current infections within the source population. To date, no viral study has been performed using the sewage of any large South American city. In this study, we used viral metagenomics to obtain a single sample snapshot of the RNA virosphere in the wastewater from Santiago de Chile, the seventh largest city in the Americas. Despite the overrepresentation of dsRNA viruses, our results show that Santiago's sewage RNA virosphere was composed mostly of unknown sequences (88%), while known viral sequences were dominated by viruses that infect bacteria (60%), invertebrates (37%) and humans (2.4%). Interestingly, we discovered three novel genogroups within the Picobirnaviridae family that can fill major gaps in this taxa's evolutionary history. We also demonstrated the dominance of emerging Rotavirus genotypes, such as G8 and G6, that have displaced other classical genotypes, which is consistent with recent clinical reports. This study supports the usefulness of sewage viral metagenomics for public health surveillance. Moreover, it demonstrates the need to monitor the viral component during the wastewater treatment and recycling process, where this virome can constitute a reservoir of human pathogens. © 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091552321&doi=10.3390%2fv12091050&partnerID=40&md5=baf80b278cf6a1efac94b334effb0564105012Thomson Reuters ISIPicobirnavirus; Rotavirus; Sewage RNA virosphere; Viral metagenomics; Wastewater
Zonas Costeras2020Gubler, S., Sedlmeier, K., Bhend, J., Avalos, G., Coelho, C. A. S., Escajadillo, Y., Jacques-Coper, M., Martinez, R., Schwierz, C., de Skansi, M., Spirig, Ch.Assessment of ECMWF SEAS5 seasonal forecast performance over South AmericaTheoretical and Applied Climatology10.1175/WAF-D-19-0106.1Seasonal predictions have a great socioeconomic potential if they are reliable and skillful. In this study, we assess the prediction performance of SEAS5, version 5 of the seasonal prediction system of the European Centre for Medium-Range Weather Forecasts (ECMWF), over South America against homogenized station data. For temperature, we find the highest prediction performances in the tropics during austral summer, where the probability that the predictions correctly discriminate different observed outcomes is 70%. In regions lying to the east of the Andes, the predictions of maximum and minimum temperature still exhibit considerable performance, while farther to the south in Chile and Argentina the temperature prediction performance is low. Generally, the prediction performance of minimum temperature is slightly lower than for maximum temperature. The prediction performance of precipitation is generally lower and spatially and temporally more variable than for temperature. The highest prediction performance is observed at the coast and over the highlands of Colombia and Ecuador, over the northeastern part of Brazil, and over an isolated region to the north of Uruguay during DJF. In general, Niño-3.4 has a strong influence on both air temperature and precipitation in the regions where ECMWF SEAS5 shows high performance, in some regions through teleconnections (e.g., to the north of Uruguay). However, we show that SEAS5 outperforms a simple empirical prediction based on Niño-3.4 in most regions where the prediction performance of the dynamical model is high, thereby supporting the potential benefit of using a dynamical model instead of statistical relationships for predictions at the seasonal scale. © 2020 American Meteorological Society.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85082037666&doi=10.1175%2fWAF-D-19-0106.1&partnerID=40&md5=3ba49409bcc615f23ab670108f9760a7561-58435Thomson Reuters ISI
Zonas Costeras2020Srain, Benjamín M., Sobarzo, M., Daneri, G., González, Humberto E., Testa, G., Farías, L., Schwarz, A., Pérez, N., Pantoja-Gutiérrez, SFermentation and Anaerobic Oxidation of Organic Carbon in the Oxygen Minimum Zone of the Upwelling Ecosystem Off Concepción, in Central ChileRevista de Biología Marina y Oceanografía10.3389/fmars.2020.00533We studied the dynamics of fermentation and anaerobic degradation of organic matter at a fixed station in the Oxygen Minimum Zone (OMZ) within the Humboldt Current System off Concepción, central Chile. Products of the main anaerobic microbial reactions [fermentation, denitrification, and reduction of Fe(OH)3 and SO42–] were analyzed during laboratory incubations of OMZ waters. Fermentation of glucose and amino acids resulted in the production of volatile fatty acids, mainly acetate; these compounds were detected year-round in in situ water samples and were associated with high primary production rates and presence of O2-deficient waters at the sampling site. In contrast, whilst ethanol was produced from glucose fermentation by OMZ water microorganisms under laboratory conditions, it was not detected in the water column during the annual cycle. Evidence of acetate oxidation (which is thermodynamically feasible), with Fe(OH)3 as an electron acceptor, suggests that microbial activity could reduce solid-phase Fe carried by rivers using fermented metabolites in oxygen-depleted water, thus releasing dissolved bioavailable Fe. Here we present evidence for productivity-driven seasonality of biogeochemical cycles in the Humboldt system, supported by fermentation and anaerobic consumption of fermentation products oxidized by a variety of electron acceptors including NO3–, Fe(OH)3, and SO42–. Our results suggest that products of fermentation in the OMZ may provide a source of labile organics for advection to oxygenated waters of subantarctic origin during austral winter. Fermentation, anaerobic oxidation and associated advection of fermentation products are likely to be enhanced during the twenty-first century due both to temperature increase and decrease in dissolved O2 in the water column. © Copyright © 2020 Srain, Sobarzo, Daneri, González, Testa, Farías, Schwarz, Pérez and Pantoja-Gutiérrez.https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089088957&doi=10.3389%2ffmars.2020.00533&partnerID=40&md5=aeb24cef8ed05d62fcb35b8ab7981a885337Thomson Reuters ISIacetate; anaerobic respiration; Chile; fermentation; oxygen minimum zone; South East Pacific; volatile fatty acids
Agua y Extremos;Zonas Costeras2020Vicencio, José., Rondanelli, Roberto., Campos, Diego., Valenzuela, Raúl., Garreaud, René., Reyes, Alejandra., Padilla, Rodrigo., Abarca, Ricardo., Barahona, Camilo., Delgado, Rodrigo., Nicora, GabrielaThe Chilean Tornado Outbreak of May 2019: Synoptic, mesoscale, and historical contextsAnnals of Agricultural and Environmental Medicine10.1175/BAMS-D-19-0218.11-52Thomson Reuters ISI
Zonas Costeras2020Wilson, Samuel T., Al-Haj, Alia N., Bourbonnais, A., Frey, C., Fulweiler, Robinson W., Kessler, John D., Marchant, Hannah K., Milucka, J., Ray, Nicholas E., Suntharalingham, P., Thornton, Brett F., Upstill-Goddard, Robert C., Weber, Thomas S., Arévalo-Martínez, Damian L., Bange, Hermann W., Benway, Heather M., Bianchi, D., Borges, Alberto V., Chang, Bonnie X., Crill, Patrick M., del Valle, Daniela A., Farías, L., Joye, Samantha B., Kock, A., Labidi, Jabrane., Manning, Cara C., Pohlman, John W., Rehder, G., Sparrow, Katy J., Tortell, Philippe D., Treude, T., Valentine, David L., Ward, Bess B., Yang, S., Yurganov, Leonid N.Ideas and perspectives: A strategic assessment of methane and nitrous oxide measurements in the marine environmentFrontiers in Plant Science10.5194/bg-17-5809-2020In the current era of rapid climate change, accurate characterization of climate-relevant gas dynamics-namely production, consumption, and net emissions-is required for all biomes, especially those ecosystems most susceptible to the impact of change. Marine environments include regions that act as net sources or sinks for numerous climateactive trace gases including methane (CH4) and nitrous oxide (N2O). The temporal and spatial distributions of CH4 and N2O are controlled by the interaction of complex biogeochemical and physical processes. To evaluate and quantify how these mechanisms affect marine CH4 and N2O cycling requires a combination of traditional scientific disciplines including oceanography, microbiology, and numerical modeling. Fundamental to these efforts is ensuring that the datasets produced by independent scientists are comparable and interoperable. Equally critical is transparent communication within the research community about the technical improvements required to increase our collective understanding of marine CH4 and N2O. A workshop sponsored by Ocean Carbon and Biogeochemistry (OCB) was organized to enhance dialogue and collaborations pertaining to marine CH4 and N2O. Here, we summarize the outcomes from the workshop to describe the challenges and opportunities for near-future CH4 and N2O research in the marine environment. © 2020 Author(s).https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097131291&doi=10.5194%2fbg-17-5809-2020&partnerID=40&md5=27b2afc49efc3a8d54c15d9c417c062c5809-582817Thomson Reuters ISI
Zonas Costeras;Agua y Extremos2019Bozkurt, D; Rondanelli, R; Carrasco, J; Boisier; Morales, B; Muñoz, F; Valdebenito, N; Del Hoyo, M.; Troncoso, M.; Bustos, S.Informe de Síntesis Simulaciones climáticas regionales para el continente AntárticoCentro de Ciencia del Clima y la Resiliencia (CR)2 (ANID/FONDAP/15110009) Universidad de Chile--published onlineNot indexed
Zonas Costeras;Agua y Extremos2019Bozkurt, D; Rondanelli, R; Carrasco, J.; Boisier, J; Morales, B; Muñoz, F; Valdebenito, N; Del Hoyo, M.; Troncoso, M.; Bustos, S.Informe de Síntesis Simulaciones climáticas regionales para el territorio insular ChilenoCentro de Ciencia del Clima y la Resiliencia (CR)2 (ANID/FONDAP/15110009) Universidad de Chile-https://cambioclimatico.mma.gob.cl/wp-content/uploads/2020/05/Informe-sintesis-simulaciones-territorio-insular.pdf-published onlineNot indexed
Zonas Costeras2019Farías, Laura; Carrasco, Cristina; Faúndez, Juan; Departamento De Oceanografia, Universidad De ConcepciónNitrous oxide and biogeochemical variables related to Intermediate Waters into Eastern South Pacific Ocean, supplement to: Carrasco, Cristina; Karstensen, Johannes; Farías, Laura (2017): On the Nitrous Oxide Accumulation in Intermediate Waters of the Eastern South Pacific Ocean. Frontiers in Marine Science, 4PANGAEA. Data Publisher for Earth & Environmental Science10.1594/PANGAEA.906231-published onlineNot indexed
Zonas Costeras2020Farías, Laura; Faúndez, JuanNitrous oxide distribution in the continental shelf off Central Chile (2005-2009)PANGAEA. Data Publisher for Earth & Environmental Science10.1594/PANGAEA.916020Nitrous oxide (N2O) is a powerful greenhouse gas principally produced by nitrification and denitrification in the marine environment. Observations were made in the eastern South Pacific (ESP), between 10º and 60°S, and ~75° to 88°W, from intermediate waters targeting Antarctic Intermediate Water (AAIW) at potential density of 27.0-27.1 kg m-3. Between 60° to 20°S, a gradual equatorward increase of N2O from 8 to 26 nmol L-1 was observed at density 27.0-27.1 kg m-3 where AAIW penetrates. Positive correlations were found between apparent N2O production (∆N2O) and O2 utilization (AOU), and between ∆N2O and NO3-, which suggested that local N2O production is predominantly produced by nitrification. Closer to the equator, between 20° and 10°S at AAIW core, a strong N2O increase up to 75 nmol L-1 was observed. Because negative correlations were found between ∆N2O vs. NO3- and ∆N2O vs. N* (a Nitrogen deficit index) and because ∆N2O and AOU do not follow a linear trend, we suspect that, in addition to nitrification, denitrification also takes place in N2O cycling. By making use of water mass mixing analyses, we show that an increase in N2O occurs in the region where high oxygen from AAIW merges with low oxygen from Equatorial Subsurface Water (ESSW), creating favorable conditions for local N2O production. We conclude that the non-linearity in the relationship between N2O and O2 is a result of mixing between two water masses with very different source characteristics, paired with the different time frames of nitrification and denitrification processes that impact water masses en route before they finally meet and mix in the ESP region.https://doi.pangaea.de/10.1594/PANGAEA.906231-published onlineNot indexed
Zonas Costeras2020Farías, Laura; Faúndez, Juan; Departamento De Oceanografia, Universidad De ConceptiónVertical profiles of nitrous oxide, methane and nutrients in coastal water of eastern South PacificPANGAEA. Data Publisher for Earth & Environmental Science10.1594/PANGAEA.922967Continental shelves tend to have high standing stocks of organic carbon and high rates of primary production relative to the open ocean and serve as important link between land and the ocean interior and between the sediment and the water column, playing a key role in the N and C balance, and accounting for up to 50% of the total N loss. One of the widest continental shelves in the eastern South Pacific (ESP) is present off central Chile (36°S). This is an important geographic feature in terms of physical and biological interactions owing to the large area available for coupling between the benthic and pelagic systems. In addition, this area is subjected to a strong coastal upwelling during austral spring and summer; when winds shift to a predominantly northward direction, stressing the sea surface layer and producing an intense cross-shelf transport and uplift of Equatorial Subsurface waters (ESSW) over the shelf. The ESSW, characterized by high NO3- and low O2 content, promotes surface fertilization and, subsequently, intense organic matter respiration and remineralization at depth, along with an efflux of subsurface-accumulated N2O (Farías et al. 2009, Cornejo & Farías, 2012). Thus, periods of maximum productivity and intense suboxia, or even anoxia, when diverse electron donors (e.g., organic matter, NH4+, NO2-, H2S) are present, represent a potential hotspot for fixed N removal processes.We present a data set that has been obtained during different FIP cruises (Fondo de Investigaciones Pesqueras) (2005-2009) which consisted of several transects perpendicular to the coast between 35° and 40°S and from the coast to 77.8° W (central Chile). Data collected include classical oceanographic variables including N2O and important greenhouse gas.https://doi.pangaea.de/10.1594/PANGAEA.916020-published onlineNot indexed
Agua y Extremos;Cambio de Uso de Suelo;Ciudades Resilientes;Gobernanza e Interfaz entre Ciencia y Política;Zonas Costeras2020Gonzalez, M. E.; Sapiains A., R.; Gómez-González, S.; Garreaud, R. D.; Miranda, A.; Galleguillos, M.; Jacques-Coper, M.; Pauchard, A.; Hoyos-Santillan, J.; Cordero, L.; Vasquez-Lavin, F.; Lara, A.; Aldunce, P.; Delgado, V.; Arriagada, R.; Ugarte, A. M.; Sepulveda-Jauregui, A.; Farias, L.; Garcia, R.; Rondanelli, R.; Ponce, R.; Vargas, F.; Rojas, M.; Boisier, J. P.; Carrasco, C.; Little, C.; Osses, M.; Zamorano, C.; Días-Hormazábal, I.; Ceballos, A.; Guerra, E.; Moncada, M.; Castillo, I.Informe a las naciones: Incendios en Chile: causas, impactos y resiliencia.CR2 publication-Chile es uno de los países más vulnerables al cambio climático, principalmente, debido a su configuración biogeográfica. Sus efectos ya se están manifestando, principalmente por una prologada y extensa sequía. En este contexto, es urgente la adopción de medidas de mitigación y adaptación para enfrentar los impactos actuales y los adversos escenarios futuros que predicen los modelos climáticos. La criósfera antártica y andina incluye los hielos continentales y marinos permanentes o estacionales, localizados en la península Antártica (PA) y en la región Subantártica (SANT), junto con el macizo Andino en su conjunto. La criósfera alberga una especial biodiversidad que sustenta una serie de subsistemas ecológicos (p. ej., vegas, bofedales, turberas, glaciares, permafrost, lagos subglaciales, tundras marinas, etc.) y servicios ecosistémicos vitales (agua, recreación, regulación climática, biodiversidad, alimento, turismo, etc.), los que están seriamente amenazados por el cambio climático, con negativas consecuencias para el medio ambiente, el clima y la sociedad (reducción del bienestar humano). La criósfera antártica y andina está siendo muy afectada por el alza global de la temperatura (IPCC, 2019). La pérdida de hielo continental en la Antártica se aceleró más de seis veces en las últimas cuatro décadas, mientras que el 87 % de los glaciares andinos monitoreados en territorio nacional exhiben algún grado de retroceso. Hoy, el hielo perdido por la Antártica es promotor de aproximadamente el 10 % del alza global en el nivel de mar; entretanto, el derretimiento de los glaciares andinos, especialmente aquellos en los Campos de Hielo patagónicos, es el responsable de cerca del 3 % del alza global en el nivel de marhttps://www.minciencia.gob.cl/comitecientifico/documentos/mesa-adaptacion/1.Adaptacion-Brechas-Aldunce.pdf1-84published onlineNot indexed
Agua y Extremos;Cambio de Uso de Suelo;Ciudades Resilientes;Gobernanza e Interfaz Ciencia y Política;Zonas Costeras2020Huneeus, N., Urquiza A., Gayó, E., Osses, M., Arriagada, R., Valdés, M., Álamos, N., Amigo, C., Arrieta, D., Basoa, K., Billi, M., Blanco, G., Boisier, J.P., Calvo, R., Casielles, I., Castro, M., Chahuán, J., Christie, D., Cordero, L., Correa, V., Cortés, J., Fleming, Z., Gajardo, N., Gallardo, L., Gómez, L., Insunza, X., Iriarte, P., Labraña, J., Lambert, F., Muñoz, A., Opazo, M., O’Ryan, R., Osses, A., Plass, M., Rivas, M., Salinas, S., Santander, S., Seguel, R., Smith, P., Tolvett, SInforme a las naciones: El aire que respiramos: pasado, presente y futuro – Contaminación atmosférica por MP2,5 en el centro y sur de ChileCR2 publication-Los resultados presentados en este informe son parte del trabajo interdisciplinario que realiza el Centro de Ciencia del Clima y la Resiliencia (CR)2. El (CR)2 es un centro de excelencia financiado por el programa FONDAP de CONICYT (Proyecto 15110009) en el cual participan cerca de 60 científicos asociados a la Universidad de Chile, la Universidad de Concepción y la Universidad Austral de Chile. La versión electrónica de este documento está disponible en el sitio web www.cr2.cl/incendioshttps://www.cr2.cl/wp-content/uploads/2020/01/Informe-CR2-IncendiosforestalesenChile.pdf1-102published onlineNot indexed
Ciudades Resilientes;Zonas Costeras;Gobernanza e Interfaz Ciencia y Política2019Palma, R.; Barría, C.; Basoa, K.; Benavente, D.; Benavides, C.; Campos, B.; de la Maza, N.; Farías, L.; Gallardo, L.; García, M. J.; Gonzales, L. E.; Guarda, F.; Guzmán, R.; Jofré, A.; Mager, J.; Martínez, R.; Montedonico, M.; Morán, L.; Muñoz, L.; Osses, M.; Pica, A.; Rojas, M.; Rudnick, A.; SanMartín, J. P.; Santander, A.; Silva, C.; Tolvett, S.; Torres, R.; Urquiza, A.; Valdivia, P.; Vicuña, S.Comité Científico COP25: Chilean NDC mitigation proposal: Methodological approach and supporting ambition. Mitigation and energy working group reportComité Científico COP25; Ministerio de Ciencia, Tecnología, Conocimiento e Innovación-This paper analyses the Chilean Nationally Determined Contributions (NDC) proposal for the mitigation component. The methodological approach and the supporting ambition of a process carried out by the Chilean Government are assessed based on the scientific evidence available and local context. The analysis is developed by representatives of four ministries and a group of 21 researchers from six universities and research centers throughout the country. This exchange experience between the Government and the scientific community enables the identification of future challenges and opportunities for the Chilean transition in terms of mitigation. This process emerges from a bridging approach led by the recently assumed Minister of Science, Technology, Knowledge and Innovation under the presidency of the Government of Chile in the Conference of the Parties (COP25) for the United Nations Framework Convention on Climate Change (UNFCCC). After a description of the methodological approach, key topics that have an impact on the NDC definition are identified and analyzed. These topics include technical, economical, and socio-environmental issues along with a description of the current socio-political context in the country. Additionally, the major uncertainties that would have the highest potential to modify the results and conclusions of this work are identified. Finally, a summary with the main conclusions and recommendations is presented. The analysis framework and key aspects identified in this exercise may be of value for other countries with similar institutional contexts.https://www.minciencia.gob.cl/comitecientifico/documentos/mesa-mitigacion-y-energia/14.Mitigation-NDC-White-Paper.pdf-published onlineNot indexed
Zonas Costeras;Cambio de Uso de Suelo;Agua y Extremos2019Stehr, A.; Álvarez, C.; Álvarez, P.; Arumí, J. L.; Baeza, C.; Barra, R.; Berroeta, C. A.; Castillo, Y.; Chiang, G.; Cotoras, D.; Crespo, S. A.; Delgado, V.; Donoso, G.; Dussaillant, A.; Ferrando, F.; Figueroa, R.; Frêne, C.; Fuster, R.; Godoy, A.; Gómez, T.; Holzapfel, E.; Huneeus, C.; Jara, M.; Little, C.; Lizama, K.; Musalem, M.; Olivares, M.; Parra, O.; Ponce, R. D.; Rivera, D.; Rodríguez, I.; Sepúlveda, A.; Somos, M.; Ugalde, F.; Urrutia, R.; Valenzuela, M.; Vargas, C.; Vargas, X.; Vásquez, S.; Vera, I. L.; Vicuña, S.; Vidal, G.; Yévenes, M.Comité Científico COP25: Recursos hídricos en Chile: Impactos y adaptación al cambio climático. Informe de la mesa de Agua.Comité Científico COP25; Ministerio de Ciencia, Tecnología, Conocimiento e Innovación-La comparación entre el período 1985-2015 y el período 2030-2060 indica una disminución generalizada de las precipitaciones en comparación con la media histórica, pues se proyectan disminuciones promedio de entre 5% y 15% para la zona comprendida entre las cuencas de los ríos Elqui (región de Coquimbo) y el Baker (región de Aysén). Estas proyecciones se acentuarían hacia la zona sur del país, sobre todo entre la cuenca del río Biobío y el límite sur de la región de Los Lagos (Rojas, 2012). De acuerdo con trabajos como Boisier et al. (2016), se han detectado tendencias climáticas recientes en precipitación que siguen la misma dirección proyectada hacia el futuro y que han sido además atribuidas a una manifestación temprana del cambio climáticohttps://www.minciencia.gob.cl/comitecientifico/documentos/mesa-agua/19.Agua-Recursos-Hidricos-Stehr.pdf-published onlineNot indexed
Ciudades Resilientes;Gobernanza e Interfaz Ciencia y Política;Zonas Costeras2020Tolvett, S.; Rondanelli, R.; Brevis, W.; Valdes, M.; Rojas, M.La importancia de la ventilación para evitar contagios de covid-19Policy Brief, Comité Científico Asesor Cambio Climático.-Nueva evidencia indica que la principal vía de transmisión de covid-19 sería por medio de aerosoles. Por lo tanto, las medidas de distanciamiento físico y lavado de manos no serían suficientes para prevenir el contagio en lugares cerrados. Se recomienda reforzar medidas como el correcto uso de mascarillas sin válvulas, trasladar en lo posible actividades al aire libre, reducir al mínimo el tiempo de exposición en lugares cerrados y el uso de filtros de ventilación. Además, sugerimos ventilar ampliamente lugares cerrados y propiciar zonas de alta ventilación, para evitar el uso de «zonas muertas» donde el cambio de aire es muy bajo; mantener la concentración de CO 2 bajo las 500 ppm y utilizar ventilación forzada y natural dentro del transporte público.9published onlineNot indexed
Zonas Costeras;Agua y Extremos2019Vicuña, S.; Aldunce, P.; Stehr, A.; Cid, F.; Rivera, A.; Alencar, K.; Álvarez, C.; Barton, J.J.; Berger, J.; Berroeta, C.; Boisier, J.P.; Bustos, E.; Bustos, S.; Correa, T.; Cortés, S.; Cubillos, L.; De la Barrera, F.; Donoso, F.; Farías, L.; Farías, D.; Fuster, R.; Gese, P.; Godoy, A.; Guerra, L.; Guida, C.; Ibarra, C.; Jadrijevic, M.; Jiliberto, R.; Lillo, G.; Medel, E.; Meruane, C.; Meza, F.; Montedónico, M.; Muñoz, J.C.; Muñoz, L.; Musalem, M.; Navarro, A.; Ovalle, C.; Palma, R.; Pelano, C.; Pica, A.; Piquer, J.; Poblete, D.; Ponce, R.; Repetto, P.; Rojas, M.; Rudnick, A.; Santis, G.; Selles, J.I.; Silva, C.; Silva, M.; Soto, D.; Ureta, S.; Vargas, C.; Vida, G.; Winckler, P.Comité Científico COP25: Lineamientos para el desarrollo de planes de adaptación: Aplicación de recursos hídricos. Informe de las mesas Adaptación y AguaComité Científico COP25; Ministerio de Ciencia, Tecnología, Conocimiento e Innovación-La planificación y sus instrumentos de aplicación, como los planes de adaptación, son herramientas fundamentales para abordar los desafíos de la adaptación a distintas escalas espaciales y sectoriales. El uso real de estas herramientas aún es limitado. Su aplicación es dispar, especialmente en el contexto de la región de América Latina. Pocos países han iniciado sus procesos de desarrollo de este tipo de herramientas, y donde se ha hecho, como en Chile, existen vacíos y brechas importantes para desarrollar su potencial. A través de un proceso participativo a lo largo del año basado en talleres con la comunidad científica, se generó una propuesta de lineamientos para el diseño, implementación y seguimiento de planes de adaptación, la que además fue implementada de manera práctica en un ejercicio hipotético de desarrollo de un Plan de Adaptación al Cambio Climático (PACC) para los Recursos Hídricos. Un lineamiento relevante tiene relación con los antecedentes y el proceso de diseño del plan. El explicitar el proceso de diseño utilizado es fundamental para otorgar transparencia y, por lo tanto, validez al plan. En el trabajo de diseño resulta crítico contar con procesos participativos que permitan identificar las principales vulnerabilidades, desafíos y objetivos hacia el futuro. En el contexto de los recursos hídricos esta necesidad es más patente, por lo que se requiere un proceso de participación lo más amplio posible, pero teniendo en cuenta que no es factible —ni deseable— que se incluyan en el desarrollo del plan medidas de adaptación muy específicas en virtud de las necesidades en cada territorio. Estas medidas se deben desarrollar, por ejemplo, en el contexto de planes de acción a una escala regional. Se propone que este proceso se desarrolle al alero de las discusiones que se van a generar respecto de los lineamientos generales de la gestión de recursos hídricos en el país, y en paralelo de las gestiones que actualmente se tienen que desarrollar para resolver los desafíos de la actual megasequíahttps://www.minciencia.gob.cl/comitecientifico/documentos/mesa-adaptacion/2.Adaptacion-LineamientosRRHH-Vicuna.pdf-published onlineNot indexed
Zonas Costeras2021Alcamán-Arias, María Estrella; Fuentes-Alburquenque, Sebastián; Vergara-Barros, Pablo; Cifuentes-Anticevic, Jerónimo; Verdugo, Josefa; Polz, Martin; Farías, Laura; Pedrós-Alió, Carlos; Díez, BeatrizCoastal Bacterial Community Response to Glacier Melting in the Western Antarctic PeninsulaMicroorganisms10.3390/microorganisms9010088Current warming in the Western Antarctic Peninsula (WAP) has multiple effects on the marine ecosystem, modifying the trophic web and the nutrient regime. In this study, the effect of decreased surface salinity on the marine microbial community as a consequence of freshening from nearby glaciers was investigated in Chile Bay, Greenwich Island, WAP. In the summer of 2016, samples were collected from glacier ice and transects along the bay for 16S rRNA gene sequencing, while in situ dilution experiments were conducted and analyzed using 16S rRNA gene sequencing and metatranscriptomic analysis. The results reveal that certain common seawater genera, such as Polaribacter, Pseudoalteromonas and HTCC2207, responded positively to decreased salinity in both the bay transect and experiments. The relative abundance of these bacteria slightly decreased, but their functional activity was maintained and increased the over time in the dilution experiments. However, while ice bacteria, such as Flavobacterium and Polaromonas, tolerated the increased salinity after mixing with seawater, their gene expression decreased considerably. We suggest that these bacterial taxa could be defined as sentinels of freshening events in the Antarctic coastal system. Furthermore, these results suggest that a significant portion of the microbial community is resilient and can adapt to disturbances, such as freshening due to the warming effect of climate change in Antarctica.https://www.mdpi.com/2076-2607/9/1/8888vol.9 is.1.0Thomson Reuters ISIaustrocedrus chilensis, climate change, climatic projections, dendroecology, nothofagus macrocarpa, south american mediterranean forest, tree rings, vaganov–shashkin-lite model, climate models, ecosystems, forestry, landforms, climate change projections, deleterious effects, endangered tree species, global climate model, mediterranean forest, mediterranean mountains, process-based modeling, tree growth modeling, biome, chronology, climate modeling, deciduous tree, dieback, extreme event, forest ecosystem, global change, global climate, growth, mediterranean environment, montane forest, tree, tree ring, twenty first century, chile
Agua y Extremos; Zonas Costeras2021Bozkurt, Deniz; Bromwich, David H.; Carrasco, Jorge; Rondanelli, RobertoTemperature and precipitation projections for the Antarctic Peninsula over the next two decades: contrasting global and regional climate model simulationsClimate Dynamics10.1007/s00382-021-05667-2This study presents near future (2020–2044) temperature and precipitation changes over the Antarctic Peninsula under the high-emission scenario (RCP8.5). We make use of historical and projected simulations from 19 global climate models (GCMs) participating in Coupled Model Intercomparison Project phase 5 (CMIP5). We compare and contrast GCMs projections with two groups of regional climate model simulations (RCMs): (1) high resolution (15-km) simulations performed with Polar-WRF model forced with bias-corrected NCAR-CESM1 (NC-CORR) over the Antarctic Peninsula, (2) medium resolution (50-km) simulations of KNMI-RACMO21P forced with EC-EARTH (EC) obtained from the CORDEX-Antarctica. A further comparison of historical simulations (1981–2005) with respect to ERA5 reanalysis is also included for circulation patterns and near-surface temperature climatology. In general, both RCM boundary conditions represent well the main circulation patterns of the historical period. Nonetheless, there are important differences in projections such as a notable deepening and weakening of the Amundsen Sea Low in EC and NC-CORR, respectively. Mean annual near-surface temperatures are projected to increase by about 0.5–1.5 ∘C across the entire peninsula. Temperature increase is more substantial in autumn and winter (∼ 2 ∘C). Following opposite circulation pattern changes, both EC and NC-CORR exhibit different warming rates, indicating a possible continuation of natural decadal variability. Although generally showing similar temperature changes, RCM projections show less warming and a smaller increase in melt days in the Larsen Ice Shelf compared to their respective driving fields. Regarding precipitation, there is a broad agreement among the simulations, indicating an increase in mean annual precipitation (∼ 5 to 10%). However, RCMs show some notable differences over the Larsen Ice Shelf where total precipitation decreases (for RACMO) and shows a small increase in rain frequency. We conclude that it seems still difficult to get consistent projections from GCMs for the Antarctic Peninsula as depicted in both RCM boundary conditions. In addition, dominant and common changes from the boundary conditions are largely evident in the RCM simulations. We argue that added value of RCM projections is driven by processes shaped by finer local details and different physics schemes that are introduced by RCMs, particularly over the Larsen Ice Shelf.http://link.springer.com/10.1007/s00382-021-05667-2vol. is.Thomson Reuters ISIadded value, antarctica, climate change, dynamical downscaling, larsen ice shelf, model evaluation, temperature extremes
Zonas Costeras; Agua y Extremos2021Carrasco, Jorge F.; Bozkurt, Deniz; Cordero, Raul R.A review of the observed air temperature in the Antarctic Peninsula. Did the warming trend come back after the early 21st hiatus?Polar Science10.1016/j.polar.2021.100653Recent changes in the near-surface air temperature (nSAT) in the Antarctic Peninsula (AP) suggests that the absence of 21st century warming on Antarctic Peninsula may be coming to end. To examine this, the long-term annual and seasonal variability of the nSAT at eight Antarctic stations located in the AP are analyzed using available data from the SCAR Reader database, complemented with data from the Chilean Weather Service (Frei and O’Higgins). An exponential lter was applied to the original annual and seasonal mean series to obtain a decadal-like variation of the nSAT. A stacked and the standardized anomaly of the nSAT record was constructed to examine the average regional behavior in the AP. Cumulative sum (CUSUM) and changepoint analysis were applied through the stacked nSAT series to highlight signi cant changes caused by variation in weather and climate. The CUSUM and bootstrapping analysis revealed two statistically signi cant breaking points during the 1978–2020 period. The rst one occurred in the late nineties ending a warming period and making the beginning of a cooling period; the second one may have taken place in the mid-2010s and could mark the end of the warming pause. These trends appear to be consistent with the changes observed in the large-scale climate modes (i.e., the Antarctic Annular Mode – AAO).https://linkinghub.elsevier.com/retrieve/pii/S1873965221000189100653vol. is.Thomson Reuters ISIair temperature, antarctic peninsula, change point, reader database, warming and cooling trends
Zonas Costeras2021Vargas, Cristian A.; Cantarero, Sebastian I.; Sepúlveda, Julio; Galán, Alexander; De Pol-Holz, Ricardo; Walker, Brett; Schneider, Wolfgang; Farías, Laura; D’Ottone, Marcela Cornejo; Walker, Jennifer; Xu, Xiaomei; Salisbury, JoeA source of isotopically light organic carbon in a low-pH anoxic marine zoneNature Communications10.1038/s41467-021-21871-4Abstract Geochemical and stable isotope measurements in the anoxic marine zone (AMZ) off northern Chile during periods of contrasting oceanographic conditions indicate that microbial processes mediating sulfur and nitrogen cycling exert a significant control on the carbonate chemistry (pH, A T , DIC and p CO 2 ) of this region. Here we show that in 2015, a large isotopic fractionation between DIC and POC, a DIC and N deficit in AMZ waters indicate the predominance of in situ dark carbon fixation by sulfur-driven autotrophic denitrification in addition to anammox. In 2018, however, the fractionation between DIC and POC was significantly lower, while the total alkalinity increased in the low-pH AMZ core, suggesting a predominance of heterotrophic processes. An isotope mass-balance model demonstrates that variations in the rates of sulfur- and nitrogen-mediated carbon fixation in AMZ waters contribute ~7–35% of the POC exported to deeper waters. Thus, dark carbon fixation should be included in assessments of future changes in carbon cycling and carbonate chemistry due to AMZ expansion.http://www.nature.com/articles/s41467-021-21871-41604vol.12.0 is.1.0Thomson Reuters ISIanoxic conditions, carbon fixation, carbonate system, denitrification, isotopic fractionation, organic carbon, particulate organic carbon, stable isotope, chile
Zonas Costeras2021Jacques‐Coper, Martín; Veloso‐Aguila, Daniel; Segura, Christian; Valencia, AmandaIntraseasonal teleconnections leading to heat waves in central ChileInternational Journal of Climatology10.1002/joc.7096https://onlinelibrary.wiley.com/doi/10.1002/joc.7096joc.7096vol. is.Thomson Reuters ISIchile, extreme events, forecast, heat waves, south america, teleconnections, temperature, tropics, anticyclonic anomalies, circulation patterns, historical periods, large-scale circulation, madden-julian oscillation, meteorological extremes, provide guidances, temperature observations, climatology
Zonas Costeras; Agua y Extremos2021Aguirre, Catalina; Flores-Aqueveque, Valentina; Vilches, Pablo; Vásquez, Alicia; Rutllant, José A.; Garreaud, RenéRecent Changes in the Low-Level Jet along the Subtropical West Coast of South AmericaAtmosphere10.3390/atmos12040465Surface winds along the subtropical west coast of South America are characterized by the quasi-weekly occurrences of low-level jet events. These short lived but intense wind events impact the coastal ocean environment. Hence, identifying long-term trends in the coastal low-level jet (CLLJ) is essential for understanding changes in marine ecosystems. Here we use ERA5 reanalysis (1979–2019) and an objective algorithm to track anticyclones to investigate recent changes in CLLJ events off central Chile (25–43 °S). Results present evidence that the number of days with intense wind (≥10 ms−1), and the number and duration of CLLJ events have significantly changed off central Chile in recent decades. There is an increase in the number of CLLJ events in the whole study area during winter (June-July-August; JJA), while during summer (December–January–February; DJF) a decrease is observed at lower latitudes (29–34 °S), and an increase is found at the southern boundary of the Humboldt system. We suggest that changes in the central pressures and frequency of extratropical, migratory anticyclones that reach the coast of South America, which force CLLJs, have played an important role in the recent CLLJ changes observed in this region.https://www.mdpi.com/2073-4433/12/4/465465vol.12.0 is.4.0Thomson Reuters ISIcoastal low-level jet, coastal winds, era5 reanalysis, humboldt up-welling system, upwelling favorable wind events
Zonas Costeras2021Baldrich, Ángela M.; Pérez-Santos, Iván; Álvarez, Gonzalo; Reguera, Beatriz; Fernández-Pena, Concepción; Rodríguez-Villegas, Camilo; Araya, Michael; Álvarez, Francisco; Barrera, Facundo; Karasiewicz, Stéphane; Díaz, Patricio A.Niche differentiation of Dinophysis acuta and D. acuminata in a stratified fjordHarmful Algae10.1016/j.hal.2021.102010Dinophysis acuta and D. acuminata are associated with lipophilic toxins in Southern Chile. Blooms of the two species coincided during summer 2019 in a highly stratified fjord system (Puyuhuapi, Chilean Patagonia). High vertical resolution measurements of physical parameters were carried out during 48 h sampling to i) explore physiological status (e.g., division rates, toxin content) and ii) illustrate the fine scale distribution of D. acuta and D. acuminata populations with a focus on water column structure and co-occurring plastid-bearing ciliates. The species-specific resources and regulators defining the realized niches (sensu Hutchinson) of the two species were identified. Differences in vertical distribution, daily vertical migration and in situ division rates (with record values, 0.76 d−1, in D. acuta), in response to the environmental conditions and potential prey availability, revealed their niche differences. The Outlying Mean Index (OMI) analysis showed that the realized niche of D. acuta (cell maximum 7 × 103 cells L−1 within the pycnocline) was characterized by sub-surface estuarine waters (salinity 23 – 25), lower values of turbulence and PAR, and a narrow niche breath. In contrast, the realized niche of D. acuminata (cell maximum 6.8 × 103 cells L−1 just above the pycnocline) was characterized by fresher (salinity 17 – 20) outflowing surface waters, with higher turbulence and light intensity and a wider niche breadth. Results from OMI and PERMANOVA analyses of co-occurring microplanktonic ciliates were compatible with the hypothesis of species such as those from genera Pseudotontonia and Strombidium constituting an alternative ciliate prey to Mesodinium. The D. acuta cell maximum was associated with DSP (OA and DTX-1) toxins and pectenotoxins; that of D. acuminata only with pectenotoxins. Results presented here contribute to a better understanding of the environmental drivers of species-specific blooms of Dinophysis and management of their distinct effects in Southern Chile.https://linkinghub.elsevier.com/retrieve/pii/S1568988321000378102010vol.103.0 is.Thomson Reuters ISIchilean fjords, dinophysis acuminata, dinophysis acuta, dsp toxins, in situ division rates, microplanktonic ciliate prey, pectenotoxins, realized niche
Zonas Costeras2021Rodríguez-Villegas, Camilo; Lee, Matthew R.; Salgado, Pablo; Figueroa, Rosa I.; Baldrich, Ángela; Pérez-Santos, Iván; Tomasetti, Stephen J.; Niklitschek, Edwin; Díaz, Manuel; Álvarez, Gonzalo; Marín, Sandra L.; Seguel, Miriam; Farías, Laura; Díaz, Patricio A.Drivers of dinoflagellate benthic cyst assemblages in the NW Patagonian Fjords System and its adjacent oceanic shelf, with a focus on harmful speciesScience of The Total Environment10.1016/j.scitotenv.2021.147378In recent decades, the alteration of coastal food webs (via aquaculture, fishing, and leisure activities), nutrient loading, and an expansion of monitoring programs have prompted an apparent worldwide rise in Harmful Algae Blooms (HABs). Over this time, a parallel increase in HABs has also been observed in the Chilean southern austral region (Patagonia fjords). HAB species like Alexandrium catenella—responsible for Paralytic Shellfish Poisoning (PSP)—are of great public concern due to their negative socioeconomic impacts and significant northward geographical range expansion. Many toxic dinoflagellate species (like A. catenella) produce benthic resting cysts, yet a holistic understanding of the physical-chemical and biological conditions influencing the distributions of cysts in this region is lacking. In this study, we measured a combination of hydrographic (temperature, salinity, and dissolved oxygen) and sediment physical-chemical properties (temperature, pH and redox potential), in addition to meiofaunal abundances –as sediment bioturbators and potential cyst predators– to determine the factors influencing dinoflagellate cyst distribution, with emphasis on A. catenella in and around a “hotspot” area of southern Chile. An analysis of similarities (ANOSIM) test revealed significant differences (p < 0.011) in cyst assemblages between the fjords and oceanic environments. Permutational Analysis of Variance (PERMANOVA) showed significant effects of sediment temperature and silt proportion in explaining differences in the cyst assemblages. A generalized linear model (GLM) indicated that sediment temperature, silt/sand, anoxic conditions, and low abundances of Harpacticoida —a meiofauna herbivore group and potential bioturbator— are associated with the higher resting cyst abundances of the harmful species A. catenella. The implications for A. catenella resting cysts dynamics are discussed, highlighting physical-chemical and biological interactions and their potential for PSP outbreak initiation.https://linkinghub.elsevier.com/retrieve/pii/S0048969721024499147378vol.785.0 is.Thomson Reuters ISIalexandrium catenella, chilean patagonia, dinoflagellate resting cysts, meiofauna, redox potential, dissolved oxygen, expansion, leisure, ph, sediments, silt, alexandrium catenellum, algae blooms, chemical and biologicals, chilean patagonium, dinoflagellate resting cyst, harmful algae, paralytic shellfish poisoning, redox potentials, redoxpotential, redox reactions, alexandrium, catenella, dinophyceae, harpacticoida
Zonas Costeras2021Farías, L.; Tenorio, S.; Sanzana, K.; Faundez, J.Temporal methane variability in the water column of an area of seasonal coastal upwelling: A study based on a 12 year time seriesProgress in Oceanography10.1016/j.pocean.2021.102589Temporal distribution of dissolved CH4 was analysed in a zone of strong seasonal coastal upwelling off central Chile (36.5°S,73°W). Observations were taken from a twelve-year time series that included monthly sampling of the water at eight depths. CH4 concentration fluctuated between 1.75 and 100.9 nmol L-1 (or 67.11% and 3965% of saturation), with the highest levels at bottom waters, which increase as upwelling evolved. Three kind of CH4 profiles were identified; a classical diffusion–advection distribution, with bottom/surface CH4 concentration ratio > 2, was predominantly observed in ~ 54% of the all profiles and attributed to high CH4 production in the sediments during coastal upwelling season (austral spring-summer); a period of higher biological productivity, as well as in hypoxic/anoxic condition. In contrast, relatively homogeneous profiles (CH4 level ratio between bottom and surface depth < 2) was observed about ~ 46% of all profiles during periods of extreme vertical mixing (such as winter storms). Furthermore, irregular CH4 profile with superficial peaks occurring between the surface and 15–30 m depth was likely observed. These peaks indicated that local production rates exceed turbulent mixing rates, suggesting a rapid CH4 cycling due to microbial processes on the surface. Despite the fact that strong seasonality was observed in most oceanographic variables, according to favourable and non-favourable upwelling periods, only a weak seasonality was observed in CH4 content and its air-sea flux, the latter ranged from 1.27 to 47.02 µmol m−2 d-1 (mean ± SD: 10.94 ± 7.48). The annual weighted mean CH4 effluxes during upwelling (64%) and non-upwelling (36%) periods fluctuated from 1.66 to 6.22 mmol m−2 (mean ± SD: 3.40 ± 1.43), highlighting the importance of the continental shelf under the influence of coastal upwelling as a significant CH4 source toward the atmosphere.https://linkinghub.elsevier.com/retrieve/pii/S0079661121000768102589vol.195.0 is.Thomson Reuters ISImixing, storms, time series, biological productivity, coastal upwelling, concentration ratio, continental shelves, local production, microbial process, temporal distribution, turbulent mixing, coastal engineering
Zonas Costeras2021De La Fuente, María José; De la Iglesia, Rodrigo; Farias, Laura; Daims, Holger; Lukumbuzya, Michael; Vargas, Ignacio T.Electrochemical enrichment of marine denitrifying bacteria to enhance nitrate metabolization in seawaterJournal of Environmental Chemical Engineering10.1016/j.jece.2021.105604High concentrations of nitrate from industrial discharges to coastal marine environments are a matter of concern owing to their ecological consequences. In the last years, Bioelectrochemical Denitrification Systems (BEDS) have emerged as a promising nitrate removal technology. However, they still have limitations, such as the enrichment strategy for specific microbial communities in the electrodes under natural conditions. In this study, three-electrode electrochemical cells were used to test microbial enrichment from natural seawater by applying three reported potentials associated with the dissimilatory denitrification process (−130, −260, and −570 mV vs. Ag/AgCl). The microbial community analysis showed that by applying −260 mV (vs. Ag/AgCl) to the working electrode, it was possible to significantly enrich denitrifying microorganisms, specifically Marinobacter, in comparison with the control. Furthermore, −260 mV (vs. Ag/AgCl) led to a significantly higher nitrate removal than other conditions, which, combined with cyclic voltammetry analysis, suggested that the polarized electrodes worked as external electron donors for nitrate reduction. Hence, this work demonstrates for the first time that it is possible to enrich marine denitrifying microorganisms by applying an overpotential of −260 mV (vs. Ag/AgCl) without the need for a culture medium, the addition of an exogenous electron donor (i.e., organic matter) or a previously enriched inoculum.https://linkinghub.elsevier.com/retrieve/pii/S2213343721005819105604vol.9.0 is.4.0Thomson Reuters ISIbioelectrochemical denitrification system, marine denitrifying bacteria, microbial enrichment, nitrate
Agua y Extremos; Zonas Costeras2021Demortier, Alan; Bozkurt, Deniz; Jacques-Coper, MartínIdentifying key driving mechanisms of heat waves in central ChileClimate Dynamics10.1007/s00382-021-05810-zThis study explores the main drivers of heat wave (HW) events in central Chile using state-of-the-art reanalysis data (ERA5) and observations during the extended austral summer season (November to March) for the period 1979–2018. Frequency and intensity aspects of the HW events are considered using the total number of the HW events per season and the amplitude. We first contrast ERA5 with several surface meteorological stations in central Chile to evaluate its ability to capture daily maximum temperature variability and the HW events. We then use synoptic- and large-scale fields and teleconnection patterns to address the most favorable conditions of the HW events from a climatological perspective as well as from the extreme January 2017 HW event that swept central Chile with temperature records and wildfires. ERA5 tends to capture temperature extremes and the HW events at the inland stations; on the contrary, it has difficulties in capturing the maximum temperature variability at the coastal stations, which is plausible given the complex terrain features and confined coastal climate zone (only ∼7% of all grid boxes within central Chile). The composite HW days based on ERA5 reveals a mid-level trough-ridge dipole pattern exhibiting a blocking anticyclone on the surface over a large part of southwest South America. Relatively dry and warm easterly flow appears to accompany the anomalous warming in a large part of central Chile. The temporal evolution of the HW events yields a wave-like propagation pattern and enhancement of trough-ridge pattern along the South Pacific. This meridional dipole pattern is found to be largely associated with the Pacific South American pattern. In addition, the Madden–Julian Oscillation (MJO) appears to be a key component of the HW events in central Chile. In particular, while active MJO phases 2 and 7 promote sub-seasonal patterns that favor the South Pacific dipole mode, synoptic anomalies can superimpose on them and favor the formation of a migrating anticyclone over central-southern Chile and coastal lows over central Chile. Agreeing with the climatological findings, the extreme January 2017 HW analysis suggests that an eastward migratory mid-latitude trough-ridge pattern associated with MJO phase 2 was at work. We highlight that in addition to large- and synoptic-scale features, sub-synoptic processes such as coastal lows can have an important role in shaping the HW events and can lead to amplification of temperature extremes during the HW events.https://link.springer.com/10.1007/s00382-021-05810-zvol. is.Thomson Reuters ISIatmospheric teleconnections, blocking pattern, central chile, heat waves, mjo, temperature extremes
Zonas Costeras2021Pizarro, Jaime; Vergara, Pablo M.; Cerda, Sergio; Cordero, Raúl R.; Castillo, Ximena; Rowe, Penny M.; Casassa, Gino; Carrasco, Jorge; Damiani, Alessandro; Llanillo, Pedro J.; Lambert, Fabrice; Rondanelli, Roberto; Huneeus, Nicolas; Fernandoy, Francisco; Alfonso, Juan; Neshyba, StevenContaminant emissions as indicators of chemical elements in the snow along a latitudinal gradient in southern AndesScientific Reports10.1038/s41598-021-93895-1Abstract The chemical composition of snow provides insights on atmospheric transport of anthropogenic contaminants at different spatial scales. In this study, we assess how human activities influence the concentration of elements in the Andean mountain snow along a latitudinal transect throughout Chile. The concentration of seven elements (Al, Cu, Fe, Li, Mg, Mn and Zn) was associated to gaseous and particulate contaminants emitted at different spatial scales. Our results indicate carbon monoxide (CO) averaged at 20 km and nitrogen oxide (NOx) at 40 km as the main indicators of the chemical elements analyzed. CO was found to be a significant predictor of most element concentrations while concentrations of Cu, Mn, Mg and Zn were positively associated to emissions of NOx. Emission of 2.5 μm and 10 μm particulate matter averaged at different spatial scales was positively associated to concentration of Li. Finally, the concentration of Zn was positively associated to volatile organic compounds (VOC) averaged at 40 km around sampling sites. The association between air contaminants and chemical composition of snow suggests that regions with intensive anthropogenic pollution face reduced quality of freshwater originated from glacier and snow melting.http://www.nature.com/articles/s41598-021-93895-114530vol.11.0 is.1.0Thomson Reuters ISI-
Zonas Costeras2021Alarcón-Schumacher, Tomás; Guajardo-Leiva, Sergio; Martinez-Garcia, Manuel; Díez, BeatrizEcogenomics and Adaptation Strategies of Southern Ocean Viral CommunitiesmSystems10.1128/mSystems.00396-21Viruses are the most abundant biologic entities in marine systems and strongly influence the microbial community composition and diversity. However, little is known about viral communities’ adaptation and diversification in the ocean. , ABSTRACT The Southern Ocean (SO) represents up to one-fifth of the total carbon drawdown worldwide. Intense selective pressures (low temperature, high UV radiation, and strong seasonality) and physical isolation characterize the SO, serving as a “natural” laboratory for the study of ecogenomics and unique adaptations of endemic viral populations. Here, we report 2,416 novel viral genomes from the SO, obtained from newly sequenced viral metagenomes in combination with mining of publicly available data sets, which represents a 25% increase in the SO viral genomes reported to date. They comprised 567 viral clusters (defined as approximately genus-level groups), with 186 genera endemic to the SO, demonstrating that the SO viral community is predominantly constituted by a large pool of genetically divergent viral species from widespread viral families. The predicted proteome from SO viruses revealed that several protein clusters related to cold-shock-event responses and quorum-sensing mechanisms involved in the lysogenic-lytic cycle shift decision were under positive selection, which is ultimately important for fine adaptation of viral populations in response to the strong selective pressures of the SO. Finally, changes in the hydrophobicity patterns and amino acid frequencies suggested marked temperature-driven genetic selection of the SO viral proteome. Our data provide valuable insights into how viruses adapt and remain successful in this extreme polar marine environment. IMPORTANCE Viruses are the most abundant biologic entities in marine systems and strongly influence the microbial community composition and diversity. However, little is known about viral communities’ adaptation and diversification in the ocean. In this work, we take advantage of the geographical isolation and the intense selective pressures of the SO, to which viruses are exposed, to identify potential viral adaptations due to positive environmental selection and dispersal limitation. To that end, we recovered more than two thousand novel viral genomes, revealing a high degree of divergence in these SO endemic communities. Furthermore, we describe remarkable viral adaptations in amino acid frequencies and accessory proteins related to cold shock response and quorum sensing that allow them to thrive at lower temperatures. Consequently, our work greatly expands the understanding of the diversification of the viral communities of the SO and their particular adaptations to low temperatures.https://journals.asm.org/doi/10.1128/mSystems.00396-21vol. is.Thomson Reuters ISImolecular and physiological adaptations, southern ocean, stress adaptation, viral diversity
Zonas Costeras2021Tamayo-Leiva, Javier; Cifuentes-Anticevic, Jerónimo; Aparicio-Rizzo, Pilar; Arroyo, José Ignacio; Masotti, Italo; Díez, BeatrizInfluence of Estuarine Water on the Microbial Community Structure of Patagonian FjordsFrontiers in Marine Science10.3389/fmars.2021.611981Fjords are sensitive areas affected by climate change and can act as a natural laboratory to study microbial ecological processes. The Chilean Patagonian fjords (41–56°S), belonging to the Subantarctic ecosystem (46–60°S), make up one of the world’s largest fjord systems. In this region, Estuarine Water (EW) strongly influences oceanographic conditions, generating sharp gradients of oxygen, salinity and nutrients, the effects of which on the microbial community structure are poorly understood. During the spring of 2017 we studied the ecological patterns (dispersal and oceanographic factors) underlying the microbial community distribution in a linear span of 450 km along the estuarine-influenced Chilean Patagonian fjords. Our results show that widespread microbial dispersion existed along the fjords where bacterioplankton exhibited dependence on the eukaryotic phytoplankton community composition. This dependence was particularly observed under the low chlorophyll- a conditions of the Baker Channel area, in which a significant relationship was revealed between SAR11 Clade III and the eukaryotic families Pyrenomonadaceae (Cryptophyte) and Coccomyxaceae (Chlorophyta). Furthermore, dissolved oxygen and salinity were revealed as the main drivers influencing the surface marine microbial communities in these fjords. A strong salinity gradient resulted in the segregation of the Baker Channel prokaryotic communities from the rest of the Patagonian fjords. Likewise, Microbacteriaceae, Burkholderiaceae and SAR11 Clade III, commonly found in freshwater, were strongly associated with EW conditions in these fjords. The direct effect of EW on the microbial community structure and diversity of the fjords exemplifies the significance that climate change and, in particular, deglaciation have on this marine region and its productivity.https://www.frontiersin.org/articles/10.3389/fmars.2021.611981/full611981vol.8.0 is.Thomson Reuters ISIbacterioplankton, estuarine water, eukaryotic phytoplankton, microbial indicator, patagonian fjords, subantarctic
Zonas Costeras2021Bravo, Claudio; Bozkurt, Deniz; Ross, Andrew N.; Quincey, Duncan J.Projected increases in surface melt and ice loss for the Northern and Southern Patagonian IcefieldsScientific Reports10.1038/s41598-021-95725-wAbstract The Northern Patagonian Icefield (NPI) and the Southern Patagonian Icefield (SPI) have increased their ice mass loss in recent decades. In view of the impacts of glacier shrinkage in Patagonia, an assessment of the potential future surface mass balance (SMB) of the icefields is critical. We seek to provide this assessment by modelling the SMB between 1976 and 2050 for both icefields, using regional climate model data (RegCM4.6) and a range of emission scenarios. For the NPI, reductions between 1.5 m w.e. (RCP2.6) and 1.9 m w.e. (RCP8.5) were estimated in the mean SMB during the period 2005–2050 compared to the historical period (1976–2005). For the SPI, the estimated reductions were between 1.1 m w.e. (RCP2.6) and 1.5 m w.e. (RCP8.5). Recently frontal ablation estimates suggest that mean SMB in the SPI is positively biased by 1.5 m w.e., probably due to accumulation overestimation. If it is assumed that frontal ablation rates of the recent past will continue, ice loss and sea-level rise contribution will increase. The trend towards lower SMB is mostly explained by an increase in surface melt. Positive ice loss feedbacks linked to increasing in meltwater availability are expected for calving glaciers.https://www.nature.com/articles/s41598-021-95725-w16847vol.11.0 is.1.0Thomson Reuters ISIarticle, body weight, climate, glacier, sea level rise
Agua y Extremos; Zonas Costeras2021Aguirre, Catalina; Garreaud, René; Belmar, Lucy; Farías, Laura; Ramajo, Laura; Barrera, FacundoHigh-Frequency Variability of the Surface Ocean Properties Off Central Chile During the Upwelling SeasonFrontiers in Marine Science10.3389/fmars.2021.702051The ocean off south-central Chile is subject to seasonal upwelling whose intensity is mainly controlled by the latitudinal migration of the southeast Pacific subtropical anticyclone. During austral spring and summer, the mean flow is equatorward favoring coastal upwelling, but periods of strong southerly winds are intermixed with periods of relaxed southerlies or weak northerly winds (downwelling favorable). This sub-seasonal, high-frequency variability of the coastal winds results in pronounced changes in oceanographic conditions and air-sea heat and gas exchanges, whose quantitative description has been limited by the lack of in-situ monitoring. In this study, high frequency fluctuations of meteorological, oceanographic and biogeochemical near surface variables were analyzed during two consecutive upwelling seasons (2016–17 and 2017–18) using observations from a coastal buoy located in the continental shelf off south-central Chile (36.4°S, 73°W), ∼10 km off the coast. The radiative-driven diel cycle is noticeable in meteorological variables but less pronounced for oceanographic and biogeochemical variables [ocean temperature, nitrate (NO 3 −), partial pressure of carbon dioxide ( p CO 2 sea ), pH, dissolved oxygen (DO)]. Fluorescence, as a proxy of chlorophyll- a , showed diel variations more controlled by biological processes. In the synoptic scale, 23 active upwelling events (strong southerlies, lasting between 2 and 15 days, 6 days in average) were identified, alternated with periods of relaxed southerlies of shorter duration (4.5 days in average). Upwelling events were related to the development of an atmospheric low-level coastal jet in response to an intense along-shore pressure gradient. Physical and biogeochemical surface seawater properties responded to upwelling favorable wind stress with approximately a 12-h lag. During upwelling events, SST, DO and pH decrease, while NO 3 −, p CO 2 sea , and air-sea fluxes increases. During the relaxed southerly wind periods, opposite tendencies were observed. The fluorescence response to wind variations is complex and diverse, but in many cases there was a reduction in the phytoplankton biomass during the upwelling events followed by higher values during wind relaxations. The sub-seasonal variability of the coastal ocean characterized here is important for biogeochemical and productivity studies.https://www.frontiersin.org/articles/10.3389/fmars.2021.702051/full702051vol.8.0 is.Thomson Reuters ISIair-sea exchanges, biogeochemical properties, coastal buoy observations, coastal upwelling, coastal winds, eastern boundary conditions, sub-seasonal variability