Effects of the snow cover on Antarctic sea ice and potential modulation of its response to climate change

• Published in: Annals of Glaciology
• Main Authors: Eicken, Hajo, Fischer, Holger, Lemke, Peter
• Format: Article in Journal/Newspaper
• Language: English
• Published: International Glaciological Society 1995
• Subjects: Antarctic; Weddell; Weddell Sea; Annals of Glaciology; Antarc*; Sea ice
• Online Access: https://oceanrep.geomar.de/id/eprint/46150/; https://oceanrep.geomar.de/id/eprint/46150/1/effects_of_the_snow_cover_on_antarctic_sea_ice_and_potential_modulation_of_its_response_to_climate_change.pdf; https://doi.org/10.3189/S0260305500016086

Based on presented field data, it is shown that snow contributes roughly 8% to the total mass of ice in the Weddell Sea. Snow depth averages 0.16 m on first-year ice (average thickness 0.75 m) and 0.53 m on second-year ice (average thickness 1.70 m). Due to snow loading, sea ice is depressed below water level and flooded by sea water. As a result of flooding, snow ice forms through congelation of sea water and brine in a matrix of meteoric ice (i.e. snow). Sea-ice growth has been simulated with a one-dimensional model, treating the evolution of salinity, porosity and thermal properties of the ice. Simulations demonstrate that in the presence of a snow cover, ice growth is significantly reduced. Brine volumes increase by a factor of 1.5–2, affecting properties such as ice strength. Snow-ice formation depends on the evolution of freeboard and ice permeability. Effects of accumulation-rate changes have been assessed, for the Weddell Sea with a large-scale sea-ice model accounting for snow-ice formation. Results for different scenarios are presented and compared with field data and one-dimensional simulations. The role of snow in modulating the response of Antarctic sea ice to climate change is discussed.