PDO teleconnections in Diplodon shells of Argentinean Northwest Patagonia

SOLDATI, ANALIA L.; JACOB, DORRIT E.; SCHÖNE, BERND; BIANCHI, MARIA M.

Bremen, Germany

Conferencia; The Oceans in the Earth System. International Conference 2007 and 97th Annual Meeting of the Geologische Vereinigung e.v. (GV); 2007

Geologische Vereinigung

High-resolution temporal and spatial patterns of climate change for the Patagonian region south of 45°S are indispensable for a better understanding of the Southern hemisphere and global climate system. This region is directly and dominantly influenced by the Southern Westerlies (today centered at ca. 40°S) and is indirectly affected by ENSO (El Niño-Southern Oscillation) and possibly PDO (Pacific Decadal Oscillation), as suggested by dendrochronological and stable isotope studies on Austrocedrus chilensis (Roig et al., 2006; Villalba et al., 1998). As of yet, however, this interrelation has not been substantiated satisfactorily, although ENSO or PDO teleconnections are known for areas as far south as 53° (Mantua and Hare, 2002; Schneider and Gies, 2004). We present here the first sclerochronological analyses of approximately 80 years old Diplodon chilensis patagonicus mussel shells, a previously unused climate archive, collected at different lakes of the Nahuel Huapi National Park (42ºS, Patagonia Argentina).  Annually resolved  high and low frequency PDO events were revealed, showing that even at 40º S these teleconnections exist. The fact that Diplodon shells are widely distributed in lakes and rivers of South America, supports the implementation of Diplodon shells as a very interesting high resolution climatic proxy for this region.