Sea ice kinematics and surface properties from RADARSAT synthetic aperture radar during the SHEBA drift
Sea ice kinematics and surface properties from RADARSAT synthetic aperture radar during the SHEBA drift
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SHEBA 漂移期间 RADARSAT 合成孔径雷达的海冰运动学和表面特性
DOI：
10.1029/2000jc000472
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发表时间：
2002
影响因子：
--
通讯作者：
R. E. Moritz
中科院分区：
文献类型：
--
作者：
H. Stern;R. E. Moritz
[1]卫星数据对于提供北冰洋表面热量收支观测站的大尺度背景和描述其附近海冰的空间变异性十分重要。加拿大雷达卫星在一年的漂移过程中收集了SHEBA站点的195幅合成孔径雷达图像。雷达卫星地球物理处理系统利用这些图像，通过跟踪连续图像中的特征，计算SHEBA站100公里范围内冰运动的空间模式。从冰的运动数据的离散和剪切的浮冰估计。从11月到1月，分歧很大，然后从2月到7月逐渐收敛。7月底，冰的运动特征发生变化，由分段刚性运动转变为自由漂移运动。冰的运动在9月下旬恢复到冬季的特征。因此，“运动学”夏季从7月下旬持续到9月下旬。雷达后向散射也经历了季节转换，捕捉突然开始融化（5月29日）和冻结（8月15日）。多年冰的浓度在秋季约为94%，其后向散射特征在春季保持稳定。多年和第一年的冰不能区分在夏季融化的季节，当平均后向散射与地面气温呈负相关。“热力学”夏季从5月下旬持续到8月中旬。索引术语：4207海洋学概述：北极和南极海洋学; 4275海洋学概述：遥感和电磁过程（0689）; 4540海洋学：物理：冰力学和空气/海洋/冰交换过程;关键词：海冰;合成孔径雷达（SAR）; SHEBA
[1] Satellite data are important for providing the large-scale context of the Surface Heat Budget of the Arctic Ocean (SHEBA) station and for characterizing the spatial variability of the sea ice in its vicinity. The Canadian RADARSAT satellite collected 195 synthetic aperture radar (SAR) images of the SHEBA site over the course of the 1 year drift. The RADARSAT Geophysical Processor System (RGPS) used these images to compute the spatial pattern of ice motion within 100 km of the SHEBA station by tracking features in sequential images. From the ice motion data the divergence and shear of the pack ice are estimated. The divergence is large from November to January, followed by a gradual convergence from February through July. The character of the ice motion changes at the end of July, from piecewise rigid motion to free drift. The ice motion reverts to its winterlike character in late September. Thus the “kinematic” summer runs from late July to late September. The radar backscatter also goes through seasonal transitions, capturing the abrupt onset of melt (29 May) and freeze-up (15 August). The concentration of multiyear ice is about 94% in the fall, and its backscatter signature remains stable through spring. Multiyear and first-year ice cannot be distinguished during the summer melt season, when the mean backscatter is negatively correlated with the surface air temperature. The “thermodynamic” summer runs from late May to mid-August. INDEX TERMS: 4207 Oceanography: General: Arctic and Antarctic oceanography; 4275 Oceanography: General: Remote sensing and electromagnetic processes (0689); 4540 Oceanography: Physical: Ice mechanics and air/sea/ ice exchange processes; KEYWORDS: sea ice; synthetic aperture radar (SAR); SHEBA