Five-Year Analysis of Evaposublimation Characteristics and Its Role on Surface Energy Balance SEB on a Midlatitude Continental Glacier

Abstract

As a principal pathway of moisture loss of cryosphere, the sublimation of snow or ice needs to absorb a high amount of energy to complete the phase transition, while related researches on how sublimation affects surface energy balance (SEB) are still insufficient, causing unclear conclusions. To characterize the seasonal variation of a mountain glacier's sublimation or evaporation and analysis its role on SEB, the meteorological and glaciological data over five-year measurement period (2016–2020) were obtained on the top of August-one glacier. In the non-melt period of a year (January–May and October–December), sensible heat flux H was the dominant energy contributor to glacier surface (76%), followed by net radiation Rnet (22%). Sublimation removed average 85 mm (0.4 mm/day) of water vapor from surface for the dry and windy weather, and the latent heat flux of sublimation LEE accounted for 33% of energy sinks (67% of energy was stored in the glacier Qs). In the melt period (June–September), evaposublimation (mainly composed of evaporation) reached to 36 mm (0.3 mm/day), but LEE only played a small heat sink (14%) and the Qm (the energy for melting) had the largest proportion (70%). Rnet and H contributed 81% and 15% of surface energy, respectively. Obviously, under the global climate warming, the sublimation of non-melt period seems to be effective in decrease the heating rate of glacier surface.