基于合成孔径雷达遥感的北极海冰总形变率分析

基于RADARSAT地球物理处理器系统(RGPS)的北极海冰运动散度、旋度和剪切产品,本文计算了北极海冰总形变率,给出了所有RGPS产品时空覆盖范围的总形变率空间分布和时间平均总形变率大于0.01d-1的概率分布。结果表明:对整个RGPS数据库而言(时间跨度从1996年11月至2008年4月),平均总形变率为0.020 4d-1,总形变率大于0.01d-1的数据样本为总样本的45.89%。总形变率高值主要分布在近岸海域,靠近北极点附近的总形变率相对较小。北极海冰总形变率随季节变化,夏季平均总形变率及总形变率大于0.01d-1发生概率要比冬季大,其中,夏季总形变率大于0.01d-1发生概率为59%,而冬季要比夏季低18%。其可能机制主要是,夏季北极地区温度升高,形成海冰融化-破碎-更易融化-更易破碎的放大效果,导致北极海冰总形变率变大。

Analysis of the Arctic sea ice total deformation rates based on SAR remote sensing

Total sea ice deformation rates are produced based on RADARSAT Geophysical Processer System (RGPS) dataset (divergence, vorticity and shear) in this paper, as well as the probability distribution of samples whose value of total sea ice deformation rate are lager than 0.01/d in the Arctic Ocean. The results show that mean value of total deformation rates (TDR) of whole dataset (from November 1996 to April 2008) is 0.020 4/d. There are 45.89% samples whose value of TDR are lager than 0.01/d.TDR in coast area are larger than those near North Polar. There are statistically significant differences in the average TDR between summer and winter. Both average TDR and occurrence probabilities of samples whose value of TDR are lager than 0.01/d in summer are larger than those in winter. Where probability of occurrence in summer is 59% which has 18% more than that in winter. It may be lead by the amplify effect of sea ice melting-broken-easier melting-easier broken in summer, and than it makes the Arctic sea ice TDR larger than in winter.