Geodetic Mass Balance of the Northern Patagonian Icefield from 2000 to 2012 Using Two Independent Methods
Geodetic Mass Balance of the Northern Patagonian Icefield from 2000 to 2012 Using Two Independent Methods
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DOI：
10.3389/feart.2018.00008
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发表时间：
2018-02-12
影响因子：
2.9
通讯作者：
Brun, Fanny
中科院分区：
文献类型：
--
作者：
Dussaillant, Ines;Berthier, Etienne;Brun, Fanny
我们比较了两个独立的估计海拔变化率和北方巴塔哥尼亚冰原（NPI）之间的2000年（3,856平方公里）和2012年（3,740平方公里）的空间数据的大地质量平衡。第一个是通过对2000年2月航天飞机雷达地形使命（SRTM）数字高程模型（DEM）和2012年3月地球观测卫星5号（SPOT 5）DEM进行差分获得的。第二个是通过拟合基于像素的线性海拔趋势超过118 DEM计算从高级星载热发射和反射辐射计（ASTER）2000年和2012年之间获得的立体图像。这两种方法都得到了相似的和强烈负的冰原范围的质量平衡率，分别为-1.02 +/- 0.21和-1.06 +/- 0.14m w.e.。yr（-1），这与以前的研究一致。观测到了截然不同的冰川响应，个别冰川质量平衡率范围为-0.15至-2.30 m w.e.。年（-1）（标准差= 0.49 m w. e.）年龄（-1）; N = 38）。对于个别冰川，这两种方法在误差线内一致，除了由于云在SPOT 5 DEM中采样不佳的小冰川。重要的是，我们的研究证实，除了海拔2,900米以上的地区，C波段SRTM雷达信号对NPI雪和积雪的穿透力不足。占总面积的1%以下。忽略穿透将使质量平衡仅偏离0.005 m w. e。年（-1）。ASTER方法的一个强大优势是它仅依赖于免费可用的数据，因此可以扩展到其他冰川化地区。
We compare two independent estimates of the rate of elevation change and geodetic mass balance of the Northern Patagonian Icefield (NPI) between 2000 (3,856 km(2)) and 2012 (3,740 km2) from space-borne data. The first is obtained by differencing the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) from February 2000 and a Satellite pour I'Observation de la Terre 5 (SPOT5) DEM from March 2012. The second is deduced by fitting pixel-based linear elevation trends over 118 DEMs calculated from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) stereo images acquired between 2000 and 2012. Both methods lead to similar and strongly negative icefield-wide mass balance rates of - 1.02 +/- 0.21 and - 1.06 +/- 0.14m w.e. yr(-1) respectively, which is in agreement with earlier studies. Contrasting glacier responses are observed, with individual glacier mass balance rates ranging from -0.15 to -2.30m w.e. yr(-1) (standard deviation = 0.49m w.e. yr(-1); N = 38). For individual glaciers, the two methods agree within error bars, except for small glaciers poorly sampled in the SPOT5 DEM due to clouds. Importantly, our study confirms the lack of penetration of the C-band SRTM radar signal into the NPI snow and firn except for a region above 2,900m a.s.l. covering < 1% of the total area. Ignoring penetration would bias the mass balance by only 0.005m w.e. yr(-1). A strong advantage of the ASTER method is that it relies only on freely available data and can thus be extended to other glacierized areas.