Data assimilation of satellite snow thickness products in the Arctic Ocean

点击翻译按钮获取中文摘要

Accurate monitoring and modeling of Arctic sea ice thickness is vital to understanding the region's effects on regional and global climates, shipping routes, and wildlife living on and under the ice. Satellite radar altimeters offer a valuable tool for estimating sea ice thickness, where the travel time of a radar pulse to the sea ice surface and back is measured to obtain the radar freeboard, a proxy for the height of the ice above the surrounding sea water. The method for converting radar freeboard estimates to sea ice thickness requires an assumption regarding the fractional depth of the snowpack penetrated by radar waves (a), which then return to the instrument. All current winter sea ice thickness retrieval methods assume full radar penetration through the snowpack (a = 1). A growing body of research has shown this not to be the case in reality, with snow and weather properties affecting the ability of radar waves to penetrate the snowpack. Uncertainties in the radar freeboard and assumed radar penetration contribute to the overall error in calculated sea ice thickness, with an overestimation of a causing an overestimation in sea ice thickness, without competing biases. This thesis aims to improve our understanding of CryoSat-2 snow penetration over Arctic sea ice and its representation in modelling frameworks.