Evolution of Snow Over Sea-Ice during SHEBA using the SNTHERM Snow Model

Snow processes over sea-ice are currently represented with a simple one-layer snow model in the Meteorological Service of Canada (MSC) operational forecasting systems. Although fully coupled with a multi- layer sea-ice model, the snow scheme does not represent detailed processes like snow densification, vertical profiles of density and temperature, liquid water in the snow, among others. Previous studies have shown that the widely accepted SNTHERM snow model predicts reasonably well the behavior of snow during cold periods. But this scheme has not been implemented yet in operational systems. To more realistically describe snowpack and sea ice dynamics, while preserving reasonable computing efficiency, SNTHERM has been included in MSC's physics package and coupled with the multi-layer sea-ice model. This coupled system is evaluated with forcings and validated data obtained from the Surface Heat Budget of the Arctic Ocean (SHEBA) field campaign conducted in 1997. Results with SNTHERM are compared with those obtained using MSC's current operational system; they provide an interesting framework for exploring the ice-snow interactions in the Arctic.