On the retrieval of internal temperature of Antarctica Ice Sheet by using SMOS observations
On the retrieval of internal temperature of Antarctica Ice Sheet by using SMOS observations
复制标题
利用SMOS观测反演南极冰盖内部温度
DOI：
10.1016/j.rse.2019.111405
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发表时间：
2019
影响因子：
13.5
通讯作者：
G. Picard
中科院分区：
文献类型：
--
作者：
G. Macelloni;M. Leduc;F. Montomoli;M. Brogioni;C. Ritz;G. Picard
内部温度是了解冰盖动力学的一个重要参数。冰川学模型提供了对南极洲温度分布的估计，也有一些钻孔，但目前还没有整个大陆规模的测量。对土壤水分和海洋盐度（SMOS）卫星被动L波段观测的分析表明，由于穿透深度很高（即高达1，500米），有可能推断出冰盖的深层冰川学特性，包括温度的信息。在这项研究中，温度廓线检索SMOS观测联合使用冰川和排放模式。所开发的方法在南极洲内部是有效的，那里的冰盖几乎是稳定的（即其速度限制在10 m yr−1）。这一分析指出，在若干情况下，观测到的温度剖面与冰川学模型预测的温度剖面之间存在差异。特别是，一些地球物理参数，即地热热通量和平均年积累，需要修改相对于他们的先验值，以模拟SMOS亮度温度。结果还清楚地表明，由于微波在冰中的穿透有限，随着冰厚的增加，反演剖面深度的可靠性降低。所得到的结果证明了L波段（1.4 GHz）的无源微波传感器的能力，用于调查冰盖的内部温度。
Internal temperature is an essential parameter for understanding ice sheet dynamics. Glaciological models provide estimations of temperature profiles over Antarctica and few boreholes are also available, but, at present, no measurement exists at the scale of the whole continent. The analysis of passive L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite shows that, thanks to the high penetration depth (i.e. up to 1500 m), it is possible to infer information on in depth glaciological properties of the ice sheet including temperature. In this study, the temperature profile is retrieved from SMOS observations using jointly glaciological and emission models. The developed methodology is valid in the inner part of Antarctica where the ice sheet is almost stable (i.e. its velocity is limited to 10 m yr−1). This analysis points out that in several cases, differences are observed between retrieved temperature profiles and those predicted by glaciological models. In particular, some geophysical parameters, namely the geothermal heat flux and the mean annual accumulation, need to be modified with respect to their prior values in order to simulate SMOS brightness temperatures. Results also clearly show that the reliability of the retrieved profile in depth decreases with increasing ice thickness due to the limited penetration of microwaves in the ice. The obtained results prove the capability of L band (1.4 GHz) passive microwave sensors for investigating the internal temperature of the ice-sheet.