Antarctic grounding line mapping from differential satellite radar interferometry
Antarctic grounding line mapping from differential satellite radar interferometry
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DOI：
10.1029/2011gl047109
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发表时间：
2011-05-26
影响因子：
5.2
通讯作者：
Scheuchl, B.
中科院分区：
文献类型：
--
作者：
Rignot, E.;Mouginot, J.;Scheuchl, B.
冰盖接地线的划定，即，冰从海床分离并漂浮在海洋中的过渡边界对于冰盖质量收支计算、冰盖动力学的数值模拟、冰-海洋相互作用、海洋潮汐和冰下环境至关重要。在这里，我们提出了15年的全面，高分辨率测绘接地线在南极洲使用差分卫星合成孔径雷达干涉测量（DInSAR）数据从地球遥感卫星1-2（ERS-1/2），雷达卫星1和2，和先进的陆地观测系统（ALOS）PALSAR的1994年至2009年。DInSAR直接测量浮动冰架的垂直运动响应潮汐海洋强迫毫米精度，在一个样本间距优于50米，同时在几个100公里宽的区域;与早期的方法，检测表面坡度的突变在卫星可见光图像或测高数据。在停滞和缓慢移动的地区，我们发现，在地面坡度的中断是可靠的指标接地线，但在大多数快速移动的冰川和冰流，我们的DInSAR结果显示，以前的映射有定位误差范围从几公里到超过100公里。一个更好的协议被发现与ICESat的数据，也是基于垂直运动的测量，但与检测噪声一个数量级大于DInSAR。总体而言，南极地线的DInSAR测绘完全重新定义了南极洲的海岸线。引用：Rignot，E.，J. Mouginot和B. Scheuchl（2011），南极接地线测绘差分卫星雷达干涉测量，地球物理。保留信函：38，L10504，doi：10.1029/2011GL047109。
The delineation of an ice sheet grounding line, i.e., the transition boundary where ice detaches from the bed and becomes afloat in the ocean, is critical to ice sheet mass budget calculations, numerical modeling of ice sheet dynamics, ice-ocean interactions, oceanic tides, and subglacial environments. Here, we present 15 years of comprehensive, high-resolution mapping of grounding lines in Antarctica using differential satellite synthetic-aperture radar interferometry (DInSAR) data from the Earth Remote Sensing Satellites 1-2 (ERS-1/2), RADARSAT-1 and 2, and the Advanced Land Observing System (ALOS) PALSAR for years 1994 to 2009. DInSAR directly measures the vertical motion of floating ice shelves in response to tidal oceanic forcing with millimeter precision, at a sample spacing better than 50 m, simultaneously over areas several 100 km wide; in contrast with earlier methods that detect abrupt changes in surface slope in satellite visible imagery or altimetry data. On stagnant and slow-moving areas, we find that breaks in surface slope are reliable indicators of grounding lines; but on most fast-moving glaciers and ice streams, our DInSAR results reveal that prior mappings have positioning errors ranging from a few km to over 100 km. A better agreement is found with ICESat's data, also based on measurements of vertical motion, but with a detection noise one order of magnitude larger than with DInSAR. Overall, the DInSAR mapping of Antarctic grounding lines completely redefines the coastline of Antarctica. Citation: Rignot, E., J. Mouginot, and B. Scheuchl (2011), Antarctic grounding line mapping from differential satellite radar interferometry, Geophys. Res. Lett., 38, L10504, doi: 10.1029/2011GL047109.