STABLE WATER ISOTOPE CHARACTERIZATION OF THE RECENT HYDROLOGICAL SYSTEM AT THE NORTH ANTARCTIC PENINSULA AND ITS RELATION WITH SOUTH AMERICA; IMPLICATION FOR ICE CORE INTERPRETATION.
To identify a suitable location for retrieving a shallow-depth (150-200 m) ice core at the northern Antarctic Peninsula (AP), a detailed study of the recent hydrological cycle of this region has been carried out since 2008. The study area comprehends the ice-cap of King George Island and the region adjacent to the Chilean Station OŽHiggins in the AP. Additionally, two meteorological stations in the south of Chile have collected precipitation samples during the same time span. Stable water isotope analysis of precipitation and firn cores show a low seasonal variation of δ18O values, with an annual average of around -9 to -10.5 for all regions. Co-isotope diagrams (δ18O versus δD) demonstrate a strong all year round maritime influence for both stations in Antarctica, and clear seasonal-depending influence for South America (SA). The secondary parameter deuterium excess (d = 8* δ18O- δD) seems to better preserve the seasonal variability, thus allowing the dating and estimation of accumulation rates for the firn cores. To investigate the provenance and main transportation paths of moisture masses, single backward trajectories have been calculated using an air-parcel trajectory model (NOAA-Hysplit). In general, circulation paths for the AP are very stable during the whole year, running from the Bellingshausen/Amundsen Sea and South Pacific Ocean area in north-east direction to reach the AP west coast. Areas higher than 600 m a.s.l. show promising conditions to recover a valuable glaciological registry that will allow us to evaluate the recent climate variability of this region and linkages with SA.
Helmholtz Research Programs > PACES I (2009-2013) > TOPIC 3: Lessons from the Past > WP 3.1: Past Polar Climate and inter-hemispheric Coupling