Version 1 of a sea ice module for the physics based, detailed, multi-layer SNOWPACK model

Abstract

Abstract. Sea ice is an important component of the global climate system. The presence of a snowpack covering sea ice can strongly modify the thermodynamic behaviour of the sea ice, due to the low thermal conductivity and high albedo of snow. The snowpack can be strongly stratified and change properties (density, water content, grain size and shape) throughout the seasons. Fresh water percolation during snow melt can decrease the salinity of the underlying ice, while flooding of the snow layer by saline ocean water can strongly impact both the ice mass balance and the freezing point of the snow. To capture the complex dynamics from the snowpack, we introduce modifications to the physics-based, multi-layer SNOWPACK model to simulate the snow-sea ice system. This involves modifications to the model thermodynamics and to describe water and salt transport through the snow – sea ice system by coupling the transport equation to the Richards equation. These modifications allow the snow microstructure descriptions developed in the SNOWPACK model to be applied to sea ice conditions as well. Here, we drive the model with data from Snow and Ice Mass-balance Buoys installed in the Weddell Sea in Antarctica. The model is able to simulate the temporal evolution of snow density, grain size and shape and snow wetness. The model simulations show abundant depth hoar layers and melt layers, as well as superimposed ice formation due to flooding and percolation. Gravity drainage of dense brine is underestimated as convective processes are so far neglected. Furthermore, with increasing model complexity, detailed forcing data for the simulations is required, which is difficult to acquire due to limited observations in polar regions.

Modeling the Microwave Emission of Snow on Arctic Sea Ice for Estimating the Uncertainty of Satellite Retrievals

“…With the additional use of the lookup table, the N‐ICE2015 snow pit measurements contain sufficient information so that the measured snow properties can be converted to the parameters relevant for SNOWPACK. Recently, SNOWPACK was adapted to sea ice (Wever et al, ), including sea ice relevant processes such as thermodynamic ice growth, flooding, and heat transport between the ocean/ice and snow. The model is still in the development phase.…”

Snowfall and snow accumulation during the MOSAiC winter and spring seasons

“…Snow cover on sea ice has many significant effects on the ice mass balance and general heat exchange processes between the ocean and the atmosphere (Wever et al, 2020). As snow will cover almost all Arctic sea ice by the beginning of the melt season and with albedo values close to 0.9, a large amount of the incoming solar radiation is reflected rather than absorbed into the snowpack.…”

Modeling the small-scale deposition of snow onto structured Arctic sea ice during a MOSAiC storm using snowBedFoam 1.0.

“…Lastly, snow can contribute to the ice mass as its weight reduces the freeboard, which may result in snow ice formation (Ackley et al, 1990;Sturm and Massom, 2017); the importance of this process is expected to grow in the future with the thinning of the Arctic ice (Maslanik et al, 2007;Provost et al, 2017) and increasing precipitation (Bintanja et al, 2020). Hence, snow is presented as an integral component of the ocean-sea ice-snow -atmosphere system, and quantifying its distribution is a key to a better understanding of the sea ice mass balance (Wever et al, 2020).…”