Improved Arctic Sea Ice Freeboard Retrieval from Satellite Altimetry Using Optimized Sea Surface Decorrelation Scales
Improved Arctic Sea Ice Freeboard Retrieval from Satellite Altimetry Using Optimized Sea Surface Decorrelation Scales
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DOI：
10.1029/2021jc017466
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发表时间：
2021-11
期刊：
影响因子：
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通讯作者：
J. Landy;J. Bouffard;Chris Wilson;Stefanie Rynders;Y. Aksenov;M. Tsamados
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文献类型：
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作者：
J. Landy;J. Bouffard;Chris Wilson;Stefanie Rynders;Y. Aksenov;M. Tsamados
越来越多的研究得出结论，北极海冰覆盖在变暖中的弹性基本上是由其厚度控制的。几十年来，卫星雷达和激光高度计使我们能够定期监测北冰洋大部分地区的海冰厚度。然而，一个关键的不确定性仍然在海冰厚度检索是错误的海面高度（SSH），这是传统的内插在浮冰从有限数量的铅观测沿着高度计的轨道。在这里，我们使用一个客观的映射方法来确定海面高度从所有近端的铅样本位于轨道轨道上，并从相邻的轨道内的邻域30-220（平均105）公里。SSH信号的纬向，纬向和时间去相关长度尺度的模式通过分析历史CryoSat-2北极铅观测的协方差获得，这与从高分辨率海冰-海洋模型场的等效分析中获得的尺度相匹配。我们使用这些长度尺度，以确定最佳的SSH和误差估计每个海冰浮冰的位置。通过利用来自相邻轨道的线索，我们可以将海冰雷达在轨道交叉处估计的干舷精度提高20%。区域中
A growing number of studies are concluding that the resilience of the Arctic sea ice cover in a warming is essentially controlled by its thickness. Satellite radar and laser altimeters have allowed us to routinely monitor sea ice thickness across most of the Arctic Ocean for several decades. However, a key uncertainty remaining in the sea ice thickness retrieval is the error on the sea surface height (SSH) which is conventionally interpolated at ice floes from a limited number of lead observations along the altimeter's orbital track. Here, we use an objective mapping approach to determine sea surface height from all proximal lead samples located on the orbital track and from adjacent tracks within a neighborhood of 30–220 (mean 105) km. The patterns of the SSH signal's zonal, meridional, and temporal decorrelation length scales are obtained by analyzing the covariance of historic CryoSat-2 Arctic lead observations, which match the scales obtained from an equivalent analysis of high-resolution sea ice-ocean model fields. We use these length scales to determine an optimal SSH and error estimate for each sea ice floe location. By exploiting leads from adjacent tracks, we can increase the sea ice radar freeboard precision estimated at orbital crossovers by up to 20%. In regions