Isótopos estables de agua como indicadores de la variabilidad climática en la costa oriental de la tierra de Ellsworth, Antártica Occidental
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2016
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es
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Universidad Andrés Bello
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El uso de isótopos estables de agua en testigos de hielo en Antártica es considerado una fuente de información valiosa acerca del clima y la circulación atmosférica pasada, sin embargo, para una óptima aplicación e interpretación, es necesario entender las variables y factores climáticos que afectan al sitio de extracción, para de esta manera, ajustar y validar su uso. En este trabajo, se presentan los resultados de análisis de isótopos estables de oxigeno e hidrogeno en 3 testigos de neviza (DOTT, SCH y GUPA) obtenidos en las cercanías de la Estación Polar Científica Conjunta Glaciar Unión, ubicado en la Antártica Occidental, específicamente en el límite entre la plataforma de hielo Ronne-Filchner y los Montes Ellsworth. Diversos autores, sitúan a este sector como una zona de elevado interés científico, principalmente por las posibles consecuencias que traería consigo un posible colapso de la plataforma de hielo de Ronne-Filchner, además, el aislamiento territorial del sector ha conllevado a que históricamente pocos trabajos científicos de han llevado a cabo. Lo anterior, condiciona a que exista un escaso registro meteorológico directo, por lo cual, para la comparación de los datos isotópicos se recurrió al uso de diferentes fuentes de información climática: 1) Uso de los modelos de re análisis climáticos ERA-Interim y NCEP/NCAR; 2) Compilación de base de datos con registros climáticos regionales y locales; 3) Análisis de retro trayectorias de las masas de aire mediante el uso del modelo de circulación atmosférica HYPSLIT. Los resultados indican que la señal isotópica de los testigos de neviza se ajusta de buena manera con las tasas de acumulación, temperaturas superficiales, y humedad del área fuente, además se propone que el comportamiento del modo de variabilidad atmosférica dominante de la región (SAM), tendría una influencia directa en las precipitaciones del sector. Lo anterior, sumado a una extensa cobertura glaciar (de hasta 900 m en los sectores más profundos), posiciona a la zona de estudio como un sitio de alto potencial paleo climático, el cual, (según los cálculos efectuados) ofrecería un registro temporal cercano a 20.000 años.
The use of water stable isotopes in Antarctica`s ice cores, is considered a source of valuable information about past climate and atmospheric circulation, however, for an optimal application and interpretation, is necessary understand the variables and climate factors of extraction sites, for this way, adjust and validate their use. This work presents the results analysis of stable isotopes of oxygen and hydrogen in 3 firn cores (DOTT, SCH and GUPA) obtained near to Joint Scientific Polar Station “Union Glacier", located in west Antarctica, specifically in the boundary between the Ronne-Filchner ice shelf and Ellsworth Mountains. Various authors, place this sector as an area of high scientific interest, mainly because of the possible consequences that would entail a possible collapse of the Ronne-Filchner ice shelf. In addition, the territorial isolation sector has historically led to a few scientific works have been carried out. The previous conditions, predisposes that exist a little direct meteorological record, whereby, for comparison of isotopic data was necessary the use of different sources of climate information: 1) Using re analysis climate models ERA-Interim and NCEP / NCAR; 2) Compilation of the database with regional and local climate records; 3) Analysis of retro trajectories of air masses, using the model of atmospheric circulation HYPSLIT. The results indicate that the isotopic signal from firn cores adjusts in a good way with accumulation rates, surface temperatures, and humidity area source, also proposed that the behavior of atmospheric variability dominant mode in the region (SAM) would have a direct influence on rainfall in the sector. Also, the ice thickness of extraction sites (up to 900 m) positions the study area as a site of high paleo climatic potential, which, provide a temporal record about 20,000 years in the past.
The use of water stable isotopes in Antarctica`s ice cores, is considered a source of valuable information about past climate and atmospheric circulation, however, for an optimal application and interpretation, is necessary understand the variables and climate factors of extraction sites, for this way, adjust and validate their use. This work presents the results analysis of stable isotopes of oxygen and hydrogen in 3 firn cores (DOTT, SCH and GUPA) obtained near to Joint Scientific Polar Station “Union Glacier", located in west Antarctica, specifically in the boundary between the Ronne-Filchner ice shelf and Ellsworth Mountains. Various authors, place this sector as an area of high scientific interest, mainly because of the possible consequences that would entail a possible collapse of the Ronne-Filchner ice shelf. In addition, the territorial isolation sector has historically led to a few scientific works have been carried out. The previous conditions, predisposes that exist a little direct meteorological record, whereby, for comparison of isotopic data was necessary the use of different sources of climate information: 1) Using re analysis climate models ERA-Interim and NCEP / NCAR; 2) Compilation of the database with regional and local climate records; 3) Analysis of retro trajectories of air masses, using the model of atmospheric circulation HYPSLIT. The results indicate that the isotopic signal from firn cores adjusts in a good way with accumulation rates, surface temperatures, and humidity area source, also proposed that the behavior of atmospheric variability dominant mode in the region (SAM) would have a direct influence on rainfall in the sector. Also, the ice thickness of extraction sites (up to 900 m) positions the study area as a site of high paleo climatic potential, which, provide a temporal record about 20,000 years in the past.
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Cambios Climáticos, Análisis, Antártica