Arctic sea ice freeboard from AltiKa and comparison with CryoSat-2 and Operation IceBridge
Arctic sea ice freeboard from AltiKa and comparison with CryoSat-2 and Operation IceBridge
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DOI：
10.1002/2015gl064823
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发表时间：
2015-08-28
影响因子：
5.2
通讯作者：
Ridout, Andy L.
中科院分区：
文献类型：
--
作者：
Armitage, Thomas W. K.;Ridout, Andy L.
在过去的十年里，卫星雷达高度计改善了我们对北极海冰厚度的了解。海冰厚度反演不确定性的主要来源与对雪层深度和雷达与积雪相互作用的了解不足有关。在这里，我们采用了一种从CryoSat-2获得海冰干舷的方法，该方法来自AltiKa Ka波段雷达高度计在2013-14年北极海冰生长季节的数据。10月和3月，AltiKa测量的流域平均干舷分别比CryoSat-2大4.4厘米和6.9厘米。利用2013年和2014年春季的机载激光和雷达测量，我们估计了每个传感器的有效散射水平。虽然CryoSat-2回波穿透到第一年冰的冰面，并穿透多年冰的大部分（82 +/- 3%）雪层，但AltiKa回波大致从两种冰类型的雪层中点（46 +/- 5%）散射。
Satellite radar altimeters have improved our knowledge of Arctic sea ice thickness over the past decade. The main sources of uncertainty in sea ice thickness retrievals are associated with inadequate knowledge of the snow layer depth and the radar interaction with the snow pack. Here we adapt a method of deriving sea ice freeboard from CryoSat-2 to data from the AltiKa Ka band radar altimeter over the 2013-14 Arctic sea ice growth season. AltiKa measures basin-averaged freeboards between 4.4 cm and 6.9 cm larger than CryoSat-2 in October and March, respectively. Using airborne laser and radar measurements from spring 2013 and 2014, we estimate the effective scattering horizon for each sensor. While CryoSat-2 echoes penetrate to the ice surface over first-year ice and penetrate the majority (82 +/- 3%) of the snow layer over multiyear ice, AltiKa echoes are scattered from roughly the midpoint (46 +/- 5%) of the snow layer over both ice types.