Antarctic ice-shelf thickness from satellite radar altimetry
Antarctic ice-shelf thickness from satellite radar altimetry
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DOI：
10.3189/002214311796905659
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发表时间：
2011-01-01
影响因子：
3.4
通讯作者：
Bamber, J. L.
中科院分区：
文献类型：
--
作者：
Griggs, J. A.;Bamber, J. L.
冰架厚度是冰盖和冰架下洞穴建模的一个重要边界条件。在接地线附近需要它来计算冰通量，通过与上游积累量比较以确定冰盖质量平衡。在这种质量收支方法中，冰厚度的准确性是计算中的限制因素之一。我们利用1994 - 1995年欧洲遥感卫星（ERS - 1）大地测量阶段的卫星雷达高度计数据，并辅以ERS - 1纬度极限以南区域的ICESat数据，对所有南极冰架的冰厚度进行了卫星反演。从这些仪器得出的表面高程使用克里金插值法插值到规则网格上，并使用模拟的积雪密度校正转换为冰厚度。一种新的空间可变积雪密度校正的应用显著降低了冰厚度的误差，因为此前这是主要的误差来源。与航空数据的比较显示出良好的一致性，特别是与最大冰架上的SOAR CASERTZ数据相比。偏差范围从静水压力平衡假设不成立的区域的 - 13.0米，到可能存在海洋冰的区域的53.4米。
Ice-shelf thickness is an important boundary condition for ice-sheet and sub-ice-shelf cavity modelling. It is required near the grounding line to calculate the ice flux used to determine ice-sheet mass balance by comparison with the upstream accumulation. In this mass budget approach, the accuracy of the ice thickness is one of the limiting factors in the calculation. We present a satellite retrieval of the ice thickness for all Antarctic ice shelves using satellite radar altimeter data from the geodetic phases of the European Remote-sensing Satellite (ERS-1) during 1994-95 supplemented by ICESat data for regions south of the ERS-1 latitudinal limit. Surface elevations derived from these instruments are interpolated on to regular grids using kriging, and converted to ice thicknesses using a modelled firn-density correction. The availability of a new spatial variable firn-density correction significantly reduces the error in ice thickness as this was previously the dominant error source. Comparison to airborne data shows good agreement, particularly when compared to SOAR CASERTZ data on the largest ice shelves. Biases range from -13.0 m for areas where the assumption of hydrostatic equilibrium breaks down, to 53.4m in regions where marine ice may be present.