Modeling of Interannual Snow and Ice Storage in High-Altitude Regions by Dynamic Equilibrium Concept

Abstract

The energy and mass balance model for terrestrial ice and snow is an essential tool for the future projection of interannual snow and ice storage including glaciers. However, the snow models in the hydrologic engineering field have barely considered the long-term behavior of the snow and ice storage because the time scale of glacier dynamics is much longer than those of river flow and seasonal snowmelt. This paper proposes an appropriate treatment for inland glaciers as systems in dynamic equilibrium that stay constant under a static climate condition. It is conjectured that the snow and ice vertical movement from high-elevation areas to valleys (lower elevation areas) by means of wind redistribution, avalanches, and glacial motion may be considered as an equilibrator of the snow and ice storage system because it stimulates snow and ice ablation. In order to demonstrate this concept, a simple dynamic equilibrium model for regional to global scales is proposed and applied to the Pamirs. The interannual snow and ice storage in the Pamir Mountains may lose about half of their volume by the end of 21st century by the anticipated global warming based on nine selected general circulation model (GCM) projections.