Modelling annual mass balances of eight Scandinavian glaciers using statistical models

Abstract. Glacier mass balances are mainly influenced by accumulation-season precipitation and ablation-season temperature. We use a suite of statistical models to determine the influence of accumulation-season precipitation and ablation-season temperature on annual mass balances of eight Scandinavian glaciers, ranging from near coastal, maritime glaciers to inland, continental glaciers. Accumulation-season precipitation is more important for maritime glaciers, whereas ablation-season temperature is more important for annual balances of continental glaciers. However, the importances are not stable in time. For instance, accumulation-season precipitation is more important than ablation-season temperature for all glaciers in the 30 year period 1968–1997. In this time period the Atlantic Multidecadal Oscillation (AMO) index was consistently negative and the North Atlantic Oscillation (NAO) Index was consistently positive between 1987 and 1995, both being favourable for glacier growth. Hence, the relative importance of precipitation and temperature for mass balances is possibly influenced by the AMO and the NAO. Climate sensitivities estimated by statistical models are similar to climate sensitivities based on degree-day models, but are lower than climate sensitivities of energy balance models. Hence, future projections of mass balances found with our models seem rather optimistic. Still, all average mass balances found for the years 2050 and 2100 are negative.