Measurements of net subsurface heat flux in snow and ice media in Dronning Maud Land, Antarctica

Abstract

Sub-surface heat flux plays an important role in the energy balance of snow cover, glaciers and ice sheets, and varies with the density of snow/ice media. In this paper, we report experimental observations of the sub-surface heat flux conducted in different snow and ice media in Antarctica. Experiments were conducted on low density fresh snowpack, wind compacted high density snowpack, and blue ice area in east Dronning Maud Land, Antarctica, in a radius of 10 km from Indian research station Maitri (70°46′03.98″ S and 11°41′40.72″ E). Direct measurements of net subsurface heat flux were carried out using an experimental setup consisting of heat flux plates. Two heat flux plates along with two temperature sensors were placed horizontally inside the snowpack / ice sheet at a depth of approximately 10 cm from the surface during summer season between December 2011and February 2012. The mean diurnal net subsurface heat fluxes for low density snow (location 1), high density wind compacted snow (location 2), and blue ice area (location 3) observed were 7.36±9.39 W m-2, -0.12±7.6 W m-2 and 3.20±13.32 W m-2, respectively, during the measurements periods. The amplitudes of the mean diurnal variations of net sub-surface heat flux were 14.23 W m-2, 11.42W m-2 and 18.55 W m-2 at location 1, location 2 and location 3, respectively. Mean net sub-surface heat flux was observed to be comparatively lower for wind compacted high density snow.