INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
Reconstructing the annual mass balance of the Echaurren Norte glacier (Central Andes, 33.5°S) using local and regional hydroclimatic data
MASIOKAS, M.H.; PITTE, P.; LUCKMAN, B.H.; GONZÁLEZ REYES, A.; LE QUESNE, C.; CHRISTIE, D.A.; VILLALBA, R.; RUIZ, L.; NUSSBAUMER, S.; BERTHIER, E.; BARCAZA, G.; MCPHEE, J.
Año: 2016 vol. 10 p. 927 - 927
Despite the great numberand variety of glaciers in southern South America,in situ glacier mass balance recordsare extremely scarce and glacier-climate relationships are still poorlyunderstood in this region. Here we use the longest (>35 yrs) and most completein situ mass balance record, availablefor glaciar Echaurren Norte in the Andes at ~33.5°S, to develop a minimal glaciersurface mass balance model that relies on nearby monthly precipitation and airtemperature data as forcing. This basic model is able to explain 78% of the variancein the annual glacier mass balance record over the 1978-2013 calibration period.An attribution assessment identified precipitation variability as the dominantforcing modulating annual mass balances at ECH, with temperature variationslikely playing a secondary role. A regionally-averaged series of mean annualstreamflow records from both sides of the Andesbetween ~30° and 37°S is then used to estimate, through simple linearregression, this glacier?s annual mass balance variations since 1909. Thereconstruction model captures 68% of the observed glacier mass balancevariability and shows three periods of sustained positive mass balances embeddedin an overall negative trend over the past 105 years. The three periods of sustainedpositive mass balances (centered in the 1920s-30s, in the 1980s and in thefirst decade of the 21st century) coincide with several documented glacieradvances in this region. Similar trends observed in other shorter glacier massbalance series suggest that the glaciar Echaurren Norte reconstruction is representativeof larger-scale conditions and could be useful for more detailed glaciological,hydrological and climatological assessments in this portion of the Andes.