Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band
Melt in Antarctica derived from Soil Moisture and Ocean Salinity (SMOS) observations at L band
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根据 L 波段土壤湿度和海洋盐度 (SMOS) 观测得出的南极洲融化
DOI：
10.5194/tc-14-539-2020
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Y. Kerr
中科院分区：
文献类型：
--
作者：
M. Leduc;G. Picard;G. Macelloni;A. Mialon;Y. Kerr
抽象的。南极洲融化的发生是根据土壤水分和海洋盐度（SMOS）卫星在2010-2011年和2017-2018年夏季期间的L波段观测结果得出的。检测算法是适应于从一个阈值方法以前开发的19 GHz被动微波测量的特殊传感器微波成像仪（SSM/I）和特殊传感器微波成像仪探测器（SSMIS）。从1.4和19 GHz的观测检索到的每日融化发生的比较显示出整体接近的协议，但通常观察到的SMOS在融化季节的开始几天的滞后。为了理解差异，使用微波发射辐射传输模型进行理论分析。它表明，1.4 GHz信号对液态水的灵敏度明显弱于19 GHz，如果水只存在于积雪的最高几十厘米处。相反，1.4千兆赫的测量在至少1米的范围内以及在数百米的深度内对水很敏感。这是由干雪中的大穿透深度和长波长（21 cm）解释的。我们的结论是，SMOS和高频辐射计提供有趣的补充信息融化的发生和水在积雪的位置。
Abstract. Melt occurrence in Antarctica is derived from L-band observations from the Soil Moisture and Ocean Salinity (SMOS) satellite between the austral summer 2010–2011 and 2017–2018. The detection algorithm is adapted from a threshold method previously developed for 19 GHz passive microwave measurements from the special sensor microwave imager (SSM/I) and special sensor microwave imager sounder (SSMIS). The comparison of daily melt occurrence retrieved from 1.4 and 19 GHz observations shows an overall close agreement, but a lag of few days is usually observed by SMOS at the beginning of the melt season. To understand the difference, a theoretical analysis is performed using a microwave emission radiative transfer model. It shows that the sensitivity of 1.4 GHz signal to liquid water is significantly weaker than at 19 GHz if the water is only present in the uppermost tens of centimetres of the snowpack. Conversely, 1.4 GHz measurements are sensitive to water when spread over at least 1 m and when present in depths up to hundreds of metres. This is explained by the large penetration depth in dry snow and by the long wavelength (21 cm). We conclude that SMOS and higher-frequency radiometers provide interesting complementary information on melt occurrence and on the location of the water in the snowpack.
影响因子：
64.8
作者：
Golledge, N. R.;Kowalewski, D. E.;Gasson, E. G. W.
通讯作者：
Gasson, E. G. W.