Glacier regime on the northern slope of the Himalaya (Xixibangma glaciers)

Abstract

The mass–energy exchange components and ice thickness of the Xixibangma glacier massif were evaluated during the Chinese–Russian glaciological expedition to the northern Himalaya in 1991. Long-term data from two Chinese meteorological stations were used to analyze the glacier-climatic regime in the surrounding area. It was determined that solar radiation income during the summer–autumn monsoon is half that theoretically possible because of cloudiness. Melting of the glaciers on the northern slopes of the Himalaya is driven by solar radiation (up to 86%). Continuous cold katabatic winds decrease turbulent exchange, resulting in only a minor contribution from sensible heat transfer to the heat balance of glaciers. Strong katabatic winds suppress precipitation but favor evaporation, reducing glacier melting even in the ablation zone. Evaporation is very important in the heat balance, consuming up to 57% of the heat and so limiting glacier melting. Autumn ice formation occurs as refrozen melt water in a thin snow layer on the ice surface. The mean mass balance index for the period from 1956 to 1990 of the Xixibangma glacier was negative, amounting to −34 kg m −2.