Sea ice remote sensing using AMSR-E 89-GHz channels
Sea ice remote sensing using AMSR-E 89-GHz channels
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DOI：
10.1029/2005jc003384
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发表时间：
2008-01-17
影响因子：
3.6
通讯作者：
Heygster, G.
中科院分区：
文献类型：
--
作者：
Spreen, G.;Kaleschke, L.;Heygster, G.
卫星微波辐射计在海冰浓度遥感方面的最新进展受到两项发展的推动：首先，新型传感器先进微波扫描辐射计- eos （AMSR-E）在89 GHz时提供约6 x 4公里的空间分辨率，几乎是标准传感器SSM/I在85 GHz （15 x 13公里）时分辨率的3倍。其次，一种新的算法能够从90 GHz附近的信道估计海冰浓度，尽管这些信道中大气影响增强。这可以充分利用它们的水平分辨率，比19 GHz和37 GHz附近的频道精细4倍，这是最广泛的海冰检索算法，NASA-Team和Bootstrap算法使用的频率。使用的ASI算法将Svendsen等人（1987）提出的从SSM/I 85-GHz数据中检索海冰浓度的模型与使用天气过滤器从18、23和37-GHz AMSR-E数据中获得的海洋掩模结合起来。在两次航行中，ASI、NASA-Team 2和Bootstrap算法的冰浓度与舰桥观测值的相关性分别为0.80、0.79和0.81。在整个AMSR-E期间（2002-2006），ASI和NASA-Team 2之间的系统差异低于-2 +/- 8.8%，ASI和Bootstrap之间的系统差异为1.7 +/- 10.8%。ASI算法的地球物理意义包括：(1)其较高的空间分辨率可以更好地估计大气和海洋数值模式中的关键变量，例如海洋和大气之间的热通量，特别是在海岸线附近和冰溶区。(2)它为气候研究提供了额外的冰面积和范围时间序列。
Recent progress in sea ice concentration remote sensing by satellite microwave radiometers has been stimulated by two developments: First, the new sensor Advanced Microwave Scanning Radiometer-EOS (AMSR-E) offers spatial resolutions of approximately 6 x 4 km at 89 GHz, nearly 3 times the resolution of the standard sensor SSM/I at 85 GHz (15 x 13 km). Second, a new algorithm enables estimation of sea ice concentration from the channels near 90 GHz, despite the enhanced atmospheric influence in these channels. This allows full exploitation of their horizontal resolution, which is up to 4 times finer than that of the channels near 19 and 37 GHz, the frequencies used by the most widespread algorithms for sea ice retrieval, the NASA-Team and Bootstrap algorithms. The ASI algorithm used combines a model for retrieving the sea ice concentration from SSM/I 85-GHz data proposed by Svendsen et al. (1987) with an ocean mask derived from the 18-, 23-, and 37-GHz AMSR-E data using weather filters. During two ship campaigns, the correlation of ASI, NASA-Team 2, and Bootstrap algorithms ice concentrations with bridge observations were 0.80, 0.79, and 0.81, respectively. Systematic differences over the complete AMSR-E period (2002-2006) between ASI and NASA-Team 2 are below -2 +/- 8.8%, and between ASI and Bootstrap are 1.7 +/- 10.8%. Among the geophysical implications of the ASI algorithm are: (1) Its higher spatial resolution allows better estimation of crucial variables in numerical atmospheric and ocean models, for example, the heat flux between ocean and atmosphere, especially near coastlines and in polynyas. (2) It provides an additional time series of ice area and extent for climate studies.