formation of subsurface ice layers in the RACMO snow model of Greenland's ice sheet
Summary
Machguth et al, 2016, showed in Greenland melt water storage in firn limited by near-surface ice formation, that the capacity of the firn in Greenland to retain melt water is lower than previously assumed, due to the formation of thick ice layers that prevent the melt water to percolate to underlying firn. Hence, to accurately estimate the amount of runoff water in models, the process of the formation of ice layers and their influence on the water percolation should be implemented. In this thesis we explored on how to improve the snow model used by RACMO (Regional Atmospheric Climate Model) by implementing and testing radiation penetration, capillary diffusion and free water percolation, and qualitatively analyzing the resulting density plots and the impact on the mass balance. Although no quantitative measurements on how well the model approximates reality were done, we can safely say that the effects of these processes can have a significant influence on the structure of Greenland’s firn and snow, and on the surface mass balance of Greenland’s ice sheet. This means that more research is needed on how to accurately model the snow, firn and underlying ice sheet, if one wants to make predictions on a larger scale concerning the surface mass balance or sea level rise.