Satellite Microwave remote sensing of contrasting surface water inundation changes within the Arctic-Boreal Region
Satellite Microwave remote sensing of contrasting surface water inundation changes within the Arctic-Boreal Region
复制标题
卫星微波遥感北极-北方地区地表水淹没变化对比
DOI：
10.1016/j.rse.2012.09.003
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发表时间：
2012
影响因子：
13.5
通讯作者：
K. McDonald
中科院分区：
文献类型：
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作者：
J. Watts;J. S. Kimball;L. Jones;R. Schroeder;K. McDonald
北极-北方地区的地表水淹没是动态的，强烈影响陆地-大气水、能量和碳(CO2、CH4)通量，以及对气候变化的潜在反馈。本文报告了利用卫星被动微波遥感探测到的北极-北方地区(≥50°N)和主要永久冻土区(PF区)最近(2003年至2010年)的地面淹没模式。AMSR-E FW(25公里分辨率)地图反映了微波对亚网格尺度开阔水域变化的强烈敏感性，并与从更细尺度(30米至250米分辨率)陆地卫星、MODIS和SRTM雷达(≤44W)数据得出的替代静态FW地图进行了有利的比较(0.71MOD2MOD44W)。AMSR-E反演显示了地表淹没的动态季节和年度变化，这在静态FW图中没有得到解决。AMSR-E FW记录与从盆地流量记录推断的区域干湿循环也有很好的对应关系(0.71≤R≤0.87)。AMSR-E算法的敏感性分析表明，对于区域洪水模式和季节到年度变化的有效分辨，FW反演不确定性(RMSE)的保守估计在±4.1%以内。对8年的AMSR-E记录进行的区域趋势分析表明，这一时期的北极-北方地区范围内没有明显的FW趋势，而是揭示了不同PF区内洪水变化的差异。在连续(92%的网格单元有显著趋势；p<；0.1)和不连续(82%)的PF区内检测到广泛的FW湿润，而零星/孤立的PF区显示出广泛的FW干燥趋势(71%)。这些结果与以前的研究一致，这些研究表明，在最近的气候变暖下，与PF退化和相关的地表水文学变化有关的不同区域淹没模式的证据。
Surface water inundation in the Arctic–Boreal region is dynamic and strongly influences land-atmosphere water, energy and carbon (CO2, CH4) fluxes, and potential feedbacks to climate change. Here we report on recent (2003–2010) surface inundation patterns across the Arctic–Boreal region (≥50°N) and within major permafrost (PF) zones detected using satellite passive microwave remote sensing retrievals of daily fractional open water (Fw) cover from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E). The AMSR-E Fw (25-km resolution) maps reflect strong microwave sensitivity to sub-grid scale open water variability and compare favorably (0.71≤R2≤0.84) with alternative, static Fw maps derived from finer scale (30-m to 250-m resolution) Landsat, MODIS and SRTM radar (MOD44W) data. The AMSR-E retrievals show dynamic seasonal and annual variability in surface inundation that is unresolved in the static Fw maps. The AMSR-E Fw record also corresponds strongly (0.71≤R≤0.87) with regional wet/dry cycles inferred from basin discharge records. An AMSR-E algorithm sensitivity analysis shows a conservative estimate of Fw retrieval uncertainty (RMSE) within ±4.1% for effective resolution of regional inundation patterns and seasonal to annual variability. A regional trend analysis of the 8-year AMSR-E record shows no significant Arctic–Boreal region wide Fw trend for the period, and instead reveals contrasting inundation changes within different PF zones. Widespread Fw wetting is detected within continuous (92% of grid cells with significant trend; p<0.1) and discontinuous (82%) PF zones, while sporadic/isolated PF areas show widespread (71%) Fw drying trends. These results are consistent with previous studies showing evidence of contrasting regional inundation patterns linked to PF degradation and associated changes to surface hydrology under recent climate warming.