Study of surface energy and mass balance at the edge of the Antarctic ice sheet during summer in Dronning Maud Land, East Antarctica

Abstract

This study estimates energy and mass balance at the edge of the Antarctic ice sheet close to a non-glaciated area. An automatic weather station was installed on the ice sheet, near an ice free area of Schirmacher Oasis in Dronning Maud Land, East Antarctica. Hourly snow-meteorological parameters were recorded and observed during the summer of the year 2007-08. Hourly radiative and turbulent energy fluxes were estimated at the ice surface. An ultrasonic sensor was used to measure accumulation or ablation at the glacier surface. Ground Penetrating Radar was also used to measure the changes in ice thickness at the observation point. The net radiative flux was the main heat source and the latent heat flux was the main heat sink for the ice sheet with seasonal average values of 98 W m -2 and -86.7 W m -2 respectively. There was a high ablation rate for the ice sheet near the non-glaciated area with a seasonal mean of 0.0172 m w.e. per day. Over the period 10 November 2007-7 February 2008 the mass balance was -1.53 m w.e. Good correlation (r 2 5 0.97) was observed between estimated and observed hourly ablation of the glacier. Sublimation and melt processes contributed 16.5% and 83.5% respectively to the net summer ablation.

High‐frequency observations of melt effects on snowpack stratigraphy, Kahiltna Glacier, Central Alaska Range

“…Some ablation, however, is through sublimation and evaporation and does not affect lower snow stratigraphy (Gusain et al ., ; Stichler et al ., ; Taylor et al ., ). We calculated the surface energy balance at Kbase to distinguish sublimation and evaporation from melting.…”

“…Stakes were read overnight (below freezing conditions) three times, each time yielding no change in surface height, giving us confidence that the change in stake reading each day is primarily driven by ablation, not settling and compaction. Some ablation, however, is through sublimation and evaporation and does not affect lower snow stratigraphy (Gusain et al, 2009;Stichler et al, 2001;Taylor et al, 2001). We calculated the surface energy balance at Kbase to distinguish sublimation and evaporation from melting.…”

A four-year record of the meteorological parameters, radiative and turbulent energy fluxes at the edge of the East Antarctic Ice Sheet, close to Schirmacher Oasis

“…A rise in T a up to 6.5°C in the first week of November 2007 started early melting of the ice sheet and triggered a positive feedback loop of albedo causing excessive melting during the season (Gusain et al . 2009). Net longwave radiation flux was high during the summer period compared to other seasons, due to high surface temperature of the glacier.…”

“…The method of estimation of incoming and outgoing longwave fluxes and turbulent energy fluxes are given in detail in Gusain et al . (2009), and summarized here. Net radiation shortwave flux is estimated by the equation: where α is albedo of the surface.…”

“…Gusain et al . (2009) reported surface energy and mass balance of the ice sheet close to Schirmacher Oasis during the summer of 2007–08 and reported a high ablation rate for the ice sheet. Dakshin Gangotri Glacier, a part of the ice sheet close to the Schirmacher Oasis, is reported to be retreating with varying rates during different years in the past around the glacier tongue (Shrivastava et al .…”