Analysis of velocity field, mass balance, and basal melt of the Lambert Glacier–Amery Ice Shelf system by incorporating Radarsat SAR interferometry and ICESat laser altimetry measurements
Analysis of velocity field, mass balance, and basal melt of the Lambert Glacier–Amery Ice Shelf system by incorporating Radarsat SAR interferometry and ICESat laser altimetry measurements
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DOI：
10.1029/2010jb007456
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发表时间：
2010-11
影响因子：
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通讯作者：
Jaehyung Yu;Hongxing Liu;K. Jezek;R. Warner;J. Wen
中科院分区：
文献类型：
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作者：
Jaehyung Yu;Hongxing Liu;K. Jezek;R. Warner;J. Wen
通过结合近年来的遥感数据，我们研究了东南极洲Lambert冰川- amery冰架系统所有支流冰川盆地的物质平衡。基于SAR干涉测量和ICESat激光测高获得的冰流信息，我们确定了Lambert-Amery冰川系统8个支流流域的空间格局。结合SAR干涉测量的相干信息和SAR、MODIS影像的纹理信息，对接地线位置进行了解译和细化。我们基于Radarsat三次干涉测量得到的冰速度场，结合澳大利亚和俄罗斯机载无线电回波探测（RES）的冰厚度数据和ICESat激光测高数据，计算了各支流冰川盆地的冰体积通量。分析结果表明，3个支流盆地存在显著的净正失衡，而其他5个子盆地则略有正平衡或接近于零平衡。总体而言，与以往研究相比，我们发现Lambert冰川- amery冰架系统的接地冰存在22.9±4.4 Gt a−1的正质量不平衡。整个Amery冰架的净基底融化估计为27.0±7.0 Gt a−1。从接地带到冰架前缘，融化速度迅速下降。在冰架下游部分发现了明显的基底再冻结现象。对地面冰原和冰架质量平衡的估计与最近的其他估计有很大的不同。
[1] By incorporating recently available remote sensing data, we investigated the mass balance for all individual tributary glacial basins of the Lambert Glacier–Amery Ice Shelf system, East Antarctica. On the basis of the ice flow information derived from SAR interferometry and ICESat laser altimetry, we have determined the spatial configuration of eight tributary drainage basins of the Lambert-Amery glacial system. By combining the coherence information from SAR interferometry and the texture information from SAR and MODIS images, we have interpreted and refined the grounding line position. We calculated ice volume flux of each tributary glacial basin based on the ice velocity field derived from Radarsat three-pass interferometry together with ice thickness data interpolated from Australian and Russian airborne radio echo sounding (RES) surveys and inferred from ICESat laser altimetry data. Our analysis reveals that three tributary basins have a significant net positive imbalance, while five other subbasins are slightly positive or close to zero balance. Overall, in contrast to previous studies, we find that the grounded ice in Lambert Glacier–Amery Ice Shelf system has a positive mass imbalance of 22.9 ± 4.4 Gt a−1. The net basal melting for the entire Amery Ice Shelf is estimated to be 27.0 ± 7.0 Gt a−1. The melting rate decreases rapidly from the grounding zone to the ice shelf front. Significant basal refreezing is detected in the downstream section of the ice shelf. The mass balance estimates for both the grounded ice sheet and the ice shelf mass differ substantially from other recent estimates.