Analysis of Winter and Summer Glacier Mass Balances

• Published in: Geografiska annaler. Series A, Physical geography Vol. 81; no. 4; pp. 541 - 554
• Main Authors: Dyurgerov, Mark B., Meier, Mark F.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Stockholm Swedish Society for Anthropology and Geography 01.12.1999; Svenska sällskapet för antropologi och geografi
• Subjects: Alpine glaciers; Bgi / Prodig; Climate models; Glacial ablation; Glacial accumulation; Glacier mass balance; Glaciers; Hydrometeorology; Mass balance; Nivology. Glaciology; Physical geography; Precipitation; Summer; Winter; Arctic Region; World; Alps (The); Asia; Europe; Glacier; Winter; Mountain; Seasonal variation; Climatic warming; Global change; Glacier mass balance; Summer; Meltwater
• ISSN: 0435-3676; 1468-0459
• DOI: 10.1111/j.0435-3676.1999.00082.x

Seasonal mass balance components bw(winter balance) and bs(summer balance) as well as ct(total accumulation) and at(total ablation), can be used directly to infer climate variables. In contrast, ac(net balance of the accumulation area) and aa(net balance of the ablation area), and baor bn(annual or net balance) can not. The traditional Alpine system of observations of acand aa, however, can be converted to true seasonal values bwand bsif both pairs of components are simultaneously observed for some years, because a correlation between the two pairs of components exists. We analyzed bwand bsdata and their mean, standard deviations and ratios of these to the corresponding net or annual balances for 50 glaciers with relatively long records representing different regions in the northern hemisphere. We also investigated correlations between seasonal components. A negative correlation between bwand bsexists at many glaciers. About two-thirds of the glaciers show insignificant correlations (-0.3<r<0.3), implying independence of summer and winter balances. In a few unusual cases the correlations are positive. These different correlations, or lack thereof, may offer insight into feedback conditions that must exist in this climate-related system. The correspondence of the bwand ct, and bsand at, appears to depend largely on the relative amounts of summer snowfall, a function of their climatic environment expressed as α [α =(bw+bs)/2]. The contribution of variability of bsto the net balance increases markedly with decreasing values of α. The variability of bwand bs, and therefore the net balance, has been increasing with time; whether this is due to an increase in climate variability or to other causes is not clear. It appears that bwhas been increasing with time at the highest altitudes, but bshas been increasing more rapidly especially at low altitudes; the many-glacier average net balance is becoming more negative.