Constraints on snow accumulation and firn density in Greenland using GPS receivers
Constraints on snow accumulation and firn density in Greenland using GPS receivers
复制标题
使用 GPS 接收器对格陵兰岛积雪和雪松密度进行限制
DOI：
10.3189/2015jog14j130
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发表时间：
2014
影响因子：
3.4
通讯作者：
P. K. Munneke
中科院分区：
文献类型：
--
作者：
K. Larson;J. Wahr;P. K. Munneke
摘要分析了位于格陵兰冰盖内部的三个连续运行的GPS站点的数据。传统上，这类GPS装置(将GPS天线放置在部署在冰雪中的杆子上)被用来估计当地冰盖的水平速度和方向。然而，这些数据也对磁极穿过积雪层时的垂直位移很敏感。将一种利用反射GPS信号测量雪深变化的新方法应用于格陵兰岛的GPS数据。该方法对GPS天线和地表雪层之间的垂直距离提供了约束。然后使用垂直位置和雪面高度来评估地表累积和降雪致密模型的产量，在记录最长的地点显示出比10%更好的一致性。将GPS反射法与Dye-2站点的现场积雪传感器进行比较，显示出很好的一致性，捕捉到了2012年夏季融化季节格陵兰观测到的戏剧性变化。通过从垂直位置测量中减去估计的雪面高度，可以推断出雪面的地心高度。应该可以使用这些表面高程估计来帮助验证从卫星测高获得的高程结果。
Abstract Data from three continuously operating GPS sites located in the interior of the Greenland ice sheet are analyzed. Traditionally these kinds of GPS installations (where the GPS antenna is placed on a pole deployed into the firn) are used to estimate the local horizontal speed and direction of the ice sheet. However, these data are also sensitive to the vertical displacement of the pole as it moves through the firn layer. A new method developed to measure snow depth variations with reflected GPS signals is applied to these GPS data from Greenland. This method provides a constraint on the vertical distance between the GPS antenna and the surface snow layer. The vertical positions and snow surface heights are then used to assess output from surface accumulation and firn densification models, showing agreement better than 10% at the sites with the longest records. Comparisons between the GPS reflection method and in situ snow sensors at the Dye-2 site show good agreement, capturing the dramatic changes observed in Greenland during the 2012 summer melt season. The geocentric elevation of the snow surface can be inferred by subtracting the snow surface height estimates from the vertical position measurements. It should be possible to use those surface elevation estimates to help validate elevation results obtained from satellite altimetry.