Reconstructing the annual mass balance of the Echaurren Norte glacier (Central Andes, 33.5° S) using local and regional hydroclimatic data

MASIOKAS, M.H.,; CHRISTIE, D.A.; LE QUESNE, C.; PITTE, P.; RUIZ, L.; VILLALBA, R.; LUCKMAN, B.H.; BERTHIER, E.; NUSSBAUMER, S.; GONZÁLEZ-REYES, Á.; MCPHEE, J.; BARCAZA, G.

The Cryosphere

Copernicus Publications on behalf of the European Geosciences Union

Lugar: Brussels; Año: 2016 vol. 10 p. 927 - 940

Despite the great number and variety of glaciers insouthern South America, in situ glacier mass-balance recordsare extremely scarce and glacier?climate relationships arestill poorly understood in this region. Here we use the longest( >35 years) and most complete in situ mass-balance record,available for the Echaurren Norte glacier (ECH) in the Andesat 33.5 S, to develop a minimal glacier surface massbalancemodel that relies on nearby monthly precipitationand air temperature data as forcing. This basic model is ableto explain 78% of the variance in the annual glacier massbalancerecord over the 1978?2013 calibration period. Anattribution assessment identified precipitation variability asthe dominant forcing modulating annual mass balances atECH, with temperature variations likely playing a secondaryrole. A regionally averaged series of mean annual streamflowrecords from both sides of the Andes between 30 and 37 Sis then used to estimate, through simple linear regression,this glacier?s annual mass-balance variations since 1909. Thereconstruction model captures 68% of the observed glaciermass-balance variability and shows three periods of sustainedpositive mass balances embedded in an overall negativetrend over the past 105 years. The three periods of sustainedpositive mass balances (centered in the 1920s?1930s,in the 1980s and in the first decade of the 21st century) coincidewith several documented glacier advances in this region.Similar trends observed in other shorter glacier mass-balanceseries suggest that the Echaurren Norte glacier reconstructionis representative of larger-scale conditions and could beuseful for more detailed glaciological, hydrological and climatologicalassessments in this portion of the Andes