Field Investigations of Ku-Band Radar Penetration Into Snow Cover on Antarctic Sea Ice
Field Investigations of Ku-Band Radar Penetration Into Snow Cover on Antarctic Sea Ice
复制标题
Ku 波段雷达穿透南极海冰积雪的现场调查
DOI：
10.1109/tgrs.2009.2028237
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发表时间：
2008
影响因子：
8.2
通讯作者：
A. Worby
中科院分区：
文献类型：
--
作者：
R. Willatt;K. Giles;S. Laxon;Lucar Stone;A. Worby
目前不可能监测南极海冰厚度的长期、大规模变化，因为船上和空中观测的取样有限，而这些观测构成了大部分现有厚度数据。卫星雷达测高技术已用于测量北极海冰厚度的变化，假设最高振幅的雷达回波来自雪/冰界面，因为北极的雪寒冷而干燥;然而，南极的情况可能并非如此，因为冬季气温升高和频繁的雪灾导致积雪地层更加复杂。我们提出了第一次测量雷达穿透到积雪南极海冰在Ku波段卫星雷达高度计的操作。2007年9月和10月期间，使用雪橇载雷达在东南极洲附近的海冰上采集了数据。雷达数据和雪的密度，厚度，湿度和层的实地测量，采取了一系列的位置，包括积雪与洪水，硬壳，和冰层。详细的雪坑研究表明，雪/冰界面是主要的散射表面，只有雪没有形态特征或洪水。对样带数据的分析表明，雷达的主要散射表面的平均深度仅为平均测量雪深的50%左右，这表明主要散射表面并不总是所调查的南极海冰的雪/冰界面。
Monitoring long-term, large-scale changes in the Antarctic sea ice thickness is not currently possible due to the sampling constraints of the ship-based and airborne observations which comprise most of the available thickness data. Satellite radar altimetry has been used to measure sea ice thickness variability in the Arctic where it is assumed that the highest amplitude radar return originates from the snow/ice interface as the Arctic snow is cold and dry; however, this may not be the case in the Antarctic due to more complex snow stratigraphy caused by warmer winter temperatures and frequent snow flooding. We present the first measurements of radar penetration into snow cover on Antarctic sea ice in the Ku-band at which satellite radar altimeters operate. Data were taken using a sled-borne radar on sea ice off East Antarctica during September and October 2007. Radar data and field measurements of snow density, thickness, wetness, and layers were taken over a range of locations including snow packs with flooding, hard crusts, and icy layers. Detailed snow pit studies showed that the snow/ice interface was the dominant scattering surface only for snow without morphological features or flooding. Analysis of transect data showed that the mean depth of the dominant scattering surface of the radar was only around 50% of the mean measured snow depth, indicating that the dominant scattering surface was not always the snow/ice interface for the Antarctic sea ice surveyed.