Reconciling the glacial and dendrochronological records in the Cordillera de los Andes during the past centuries: A contribution from the LOTRED-SA initiative

VILLALBA, R.; MASIOKAS, M.H.; LARA, A.; RIVERA, A.; MORALES, M.; ESPIZUA, L.; CHRISTIE, D.; DELGADO, S.; GARIBOTTI, I.A.; BONINSEGNA, J.A.; ARAVENA, J.C.; LE QUESNE, C.

Valdivia, Chile

Conferencia; International Glaciological Conference VICC 2010, Ice and Climate Change: A view from the South; 2010

Centro de Estudios Científicos

The South American continent contains a diverse array of documentary and natural climate archives that can be used to better understand climate changes and atmosphere dynamics during past centuries as discussed in the LOTRED-SA Special Issue recently published in Palaeo 3. Recognizing the inherent differences in the nature of glacial and tree-ring records, we provide a comparative assessment between dendrochronological reconstructions for temperature and precipitation and glacier fluctuations for the southern tropical (20°S), subtropical (30°S), northern Patagonian (40°S) and southern Patagonian Andes (50°S) during the past four centuries. Humid conditions were reconstructed in the Bolivian Altiplano and the subtropical Andes during the 17th and 19th centuries which are consistent with more extended glaciers in both regions during the LIA (AD 1650-1850). However, different rates of glacier retreat observed after the LIA suggest differences in the patterns of precipitation and temperature variability in these regions during the last centuries. Peak LIA advances in Patagonia occurred between the 17th and 19th centuries. Subsequently glaciers have shown a generalized pattern of retreat that has accelerated during the past few decades. This rapid retreat has been particularly pronounced in northern Patagonia after the mid-1970s, where tree-ring based temperature estimates have been the warmest of the past 400 years. This warming has been concurrent with a marked negative trend in regional precipitation. Comparisons using the long-term climate variations in the selected regions along the Andes suggest the existence of coupled interactions between tropical and extratropical modes of climate variability. This may help understand the relationships between the glacier histories available for each region.