Résumé
Several tropical and subtropical ice cores have been extracted along the Andes of South America over the last decades. In Antarctica, numerous ice core studies have been completed. In order to close the gap between tropical and polar environments in this unique 8000-km long ice core records transect, a deep ice core (122 m) has been extracted in 2007 from the San Valentin glacier (3747 m, 47 degrees S, 73 degrees W) located in the Northern Patagonian Icefield (Chile). The cold conditions at that site enable us to explore the chemical and isotopic records in terms of climate variations over the last 160 years. We will briefly present the dating of the ice and the local climate specificities. Then, we will focus on the decreasing temperature trend (-0.2 degree C per decade) exhibited by the isotopic composition of the ice over the last century. We will discuss this regional cooling in a context of a warming world regarding: (1) recent temperature reconstructions in Southern South America, (2) the influence of the well-known climate modes in this region (ENSO, PDO and SAM/AAOI), (3) the linkages to tropical climate variability and changes in the Southern Pacific Ocean.