Snow in Large-Scale Sea Ice Models: State-of-the-Art and Way Forward

Abstract:

Sea ice is a platform for snow to accumulate on and, because this platform moves and deforms with ocean currents and winds, its snow cover is astoundingly heterogeneous. Snow processes on sea ice have crucial consequences in driving the evolution of sea ice, at a cascade of temporal and spatial scales.

Although sea ice models have been developed for decades, the representation of snow in these models has remained under-addressed. This work is a contribution toward the improvement of the snow component in large-scale sea ice models. During the past few years, representations of snow physics of intermediate complexity were introduced in models of this kind, providing the tools to assess the influence of snow on sea ice. The importance, in particular, of accounting for snow stratigraphy, scattering properties and wind-driven snow processes in models has been shown using those tools. These processes are all necessary in order to realistically simulate the evolution of sea ice and, more specifically, perennial sea ice.

This work opens the way for snow-related improvements in climate models and provides modellers with some guidance in achieving this task. However, extensive In Situ observations are required to adequately constrain snow parameterizations and better quantify of the impacts of snow processes on sea ice. As such specific observations start to become available, we recommend some directions for using them in future investigations and model developments.