Winter Snow Depth on Arctic Sea Ice From Satellite Radiometer Measurements (2003–2020): Regional Patterns and Trends Geophysical Research Letters

Retrieval of snow depth on sea ice from satellite measurements has been challenging especially for multiyear ice. In this study, January-February-March monthly averaged snow depth was estimated during the 2003–2020 period from satellite radiometer measurements by combining recently developed retrieval methods for freeboard and snow-ice thickness ratio. A good agreement between snow depth from this study and that from Operational IceBridge measurements demonstrates that reliable snow depth can be estimated from satellite measurements. From the analysis of wintertime snow depth estimated from this study, a reduction of mean snow depth compared to the modified Warren climatology is noted over the entire Arctic Ocean. In addition, this study found geographically different snow depth trends: positive for multiyear ice area and negative for the other areas. Average snow depth interannual variability on multiyear ice ranges between 3 to 5 cm while smaller variability is found on first-year ice.

利用卫星观测反演海冰积雪深度一直是颇具挑战性的课题，针对多年冰（multiyear ice）的反演尤为困难。本研究结合近年来针对冰面干舷（freeboard）与雪冰厚度比（snow-ice thickness ratio）开发的反演方法，利用卫星辐射计观测数据，反演得到2003-2020年1-3月的逐月平均海冰积雪深度。本研究反演得到的积雪深度与冰桥行动（Operational IceBridge）的观测结果吻合度良好，证明利用卫星观测可获取可靠的海冰积雪深度。通过对本研究反演的冬季积雪深度进行分析，我们发现整个北冰洋（Arctic Ocean）海域的平均积雪深度相较于修正版沃伦气候数据集（modified Warren climatology）有所降低。此外，本研究发现积雪深度的变化趋势存在地理差异：多年冰区域呈正增长趋势，其余区域则呈负增长趋势。多年冰区域的积雪深度年际变幅介于3至5厘米之间，而一年冰（first-year ice）区域的年际变幅相对更小。