文章基本信息

标题：Estimating snow depth over Arctic sea ice from calibrated dual-frequency radar freeboards
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作者：Isobel R. Lawrence ; Michel C. Tsamados ; Julienne C. Stroeve 等
期刊名称：The Cryosphere
印刷版ISSN：1994-0416
电子版ISSN：1994-0424
出版年度：2018
卷号：12
期号：11
页码：3551-3564
DOI：10.5194/tc-12-3551-2018
出版社：Copernicus Publications
摘要：Snow depth on sea ice remains one of the largest uncertainties in sea ice thickness retrievals from satellite altimetry. Here we outline an approach for deriving snow depth that can be applied to any coincident freeboard measurements after calibration with independent observations of snow and ice freeboard. Freeboard estimates from CryoSat-2 (Ku band) and AltiKa (Ka band) are calibrated against data from NASA's Operation IceBridge (OIB) to align AltiKa with the snow surface and CryoSat-2 with the ice–snow interface. Snow depth is found as the difference between the two calibrated freeboards, with a correction added for the slower speed of light propagation through snow. We perform an initial evaluation of our derived snow depth product against OIB snow depth data by excluding successive years of OIB data from the analysis. We find a root-mean-square deviation of 7.7, 5.3, 5.9, and 6.7 cm between our snow thickness product and OIB data from the springs of 2013, 2014, 2015, and 2016 respectively. We further demonstrate the applicability of the method to ICESat and Envisat, offering promising potential for the application to CryoSat-2 and ICESat-2, which launched in September 2018.