Towards a fully physical representation of snow on Arctic sea ice using
a 3D snow-atmosphere model
Abstract
Snow plays a crucial role in the heat transfer between the ocean and
atmosphere in sea ice due to its insulating properties. However,
wind-induced transport causes the snow distribution to be inhomogeneous,
as snow forms dunes and accumulates mostly around pressure ridges and,
leading to a heterogeneous underlying ice growth and melt. While models
can help to understand the complex interactions of snow and sea ice,
there is currently no 3D snow cover model for sea ice that considers
detailed snow cover properties. This study presents the first
application of the 3D-snow cover-atmosphere model ALPINE3D with the
drifting snow module to Arctic sea ice. The model was calibrated and
validated with measurements from the MOSAiC expedition. Wind fields used
by the snow drift routine were generated with OpenFOAM which was forced
by observations. A sensitivity analysis showed the impact of an
increased fluid threshold on snow redistribution. The model performed
well in simulating snow transport and mass fluxes, but underestimated
erosion and poorly reproduced dune formation due to the missing dynamic
mesh. The density was partially reproduced very well by the model, but
uncertainties still exist in some cases. Comparing the surface snow
density results with 1-D SNOWPACK simulations, ALPINE3D produced smaller
differences but larger temporal variation in between setups. The study
also investigated details of deposition and erosion using cross
sections, showing good agreements of snow height differences between
model and observations and revealing spatially high-resolution
parameters such as age of deposited snow, density, and thermal
conductivity.