Effect of precipitation seasonality on climatic sensitivity of glacier mass balance

Numerical calculations are described, aimed at evaluating the influence of precipitation seasonality and seasonality concentration on climatic sensitivity of glacier mass balance. Equilibrium line altitudes (ELAs) are modeled using idealized meteorological variables, and then a warming test (+ 1 degrees C) is performed, which revealed that the effects of latitude and the annual precipitation amount are less than those of precipitation seasonality and its concentration. Calculation shows higher sensitivities for the glaciers located in a summer-precipitation climate than for those located within a winter-precipitation climate. Difference due to seasonality is enhanced with the seasonality concentration. The present study suggests that the earlier parameterization of glacier mass balance with annual precipitation amount is insufficient to describe the response of glaciers to climate change. Distribution of precipitation seasonality and its concentration suggest that many parts of the world have a summer-precipitation climate but their seasonality concentration is not significant worldwide. On the other hand, an extensive region of Asia and part of the Andes are located in the highly concentrated summer-precipitation climate. This suggests the high sensitivity of glacier mass balance in these regions to climate change. (C) 2008 Elsevier B.V. All rights reserved.