Meteorological Conditions and Surface Energy Balance on Vestfonna Ice Cap, Nordaustlandet, Svalbard
Abstract
Glaciers in Svalbard have generally retreated and thinned over the last decades in accordance with global glacier retreat, but thinning rates vary greatly across the region. To investigate the drivers of high Arctic surface mass balance we analyze the meteorological conditions and compute the surface energy balance of the western margin of the Vestfonna ice cap (2800 km2) based on a two-year automatic weather station record. Air temperatures correlate well with more southern locations on Svalbard. Mean summer temperatures were close to 0°C. Net radiation is computed from measurements of the incoming and outgoing radiation fluxes. The turbulent fluxes are computed using the bulk aerodynamic approach. A multi-layer subsurface model is used to compute temperature, density and water content of the upper 30 m and surface temperatures based on conduction and latent heat processes in the glacier. Net radiation is the dominant source of the energy available for melt. Results indicate that the subsurface heat flux is a major heat sink emphasizing the importance to account for subsurface processes in the mass budget in high Arctic climate settings. The latent heat flux is directly affected by the sea ice conditions in the adjacent sea with a monthly means increasing by up to 10 W-2 when the sea ice becomes open water thus increasing the moisture flux.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2013
- Bibcode:
- 2013AGUFM.C33A0680H
- Keywords:
-
- 0720 CRYOSPHERE Glaciers;
- 0762 CRYOSPHERE Mass balance 0764 Energy balance;
- 0798 CRYOSPHERE Modeling