Evaluating Consistency of Snow Water Equivalent Retrievals from Passive Microwave Sensors over the North Central U. S.: SSM/I vs. SSMIS and AMSR-E vs. AMSR2
Evaluating Consistency of Snow Water Equivalent Retrievals from Passive Microwave Sensors over the North Central U. S.: SSM/I vs. SSMIS and AMSR-E vs. AMSR2
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DOI：
10.3390/rs9050465
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发表时间：
2017-05
期刊：
影响因子：
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通讯作者：
E. Cho;S. Tuttle;J. Jacobs
中科院分区：
文献类型：
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作者：
E. Cho;S. Tuttle;J. Jacobs
四十年来，基于卫星的无源微波传感器在全球范围内提供了有价值的雪水当量（SWE）监测。在连续的长期SWE记录可用于科学或应用目的之前，需要在不同传感器之间保持SWE测量的一致性。目前，特殊传感器微波成像仪（SSMIS）和先进微波扫描辐射计2 （AMSR2）这两个无源传感器的SWE检索还没有被充分评估，它们彼此之间以及之前的仪器之间的比较。本文利用先进微波扫描辐射计对地观测系统（AMSR-E），对2002年11月至2011年4月F13国防气象卫星计划（DMSP）上的特殊传感器微波/成像仪（SSM/I）与F17 DMSP上的SSMIS的连续性进行了一致性评估。同样，我们评估了2007年11月至2016年4月AMSR-E和AMSR2 SWE检索结果的一致性，使用SSMIS进行连续性评估。对美国中北部1176个流域进行了分析，考虑了三种雪分类（温暖森林、草原和海洋）的差异。SSM/I和SSMIS在温暖森林类中存在显著的SWE差异，这可能是由于F13 SSM/I和F17 SSMIS传感器对亮度温度（Tb）的插值方法不同所致。基于时间序列比较和年平均偏差，AMSR2和AMSR-E之间的SWE差异通常小于SSM/I和SSMIS SWE之间的差异。最后，AMSR-E和AMSR2与SSMIS之间的空间偏差模式表明了足够的空间一致性，可以将AMSR-E和AMSR2数据集视为一个连续记录。我们的研究结果为最近基于卫星的SWE检索之间的系统差异提供了有用的信息，并为后续研究提供了建议，以确保在长期SWE记录中不同传感器之间的协调。
For four decades, satellite-based passive microwave sensors have provided valuable snow water equivalent (SWE) monitoring at a global scale. Before continuous long-term SWE records can be used for scientific or applied purposes, consistency of SWE measurements among different sensors is required. SWE retrievals from two passive sensors currently operating, the Special Sensor Microwave Imager Sounder (SSMIS) and the Advanced Microwave Scanning Radiometer 2 (AMSR2), have not been fully evaluated in comparison to each other and previous instruments. Here, we evaluated consistency between the Special Sensor Microwave/Imager (SSM/I) onboard the F13 Defense Meteorological Satellite Program (DMSP) and SSMIS onboard the F17 DMSP, from November 2002 to April 2011 using the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) for continuity. Likewise, we evaluated consistency between AMSR-E and AMSR2 SWE retrievals from November 2007 to April 2016, using SSMIS for continuity. The analysis is conducted for 1176 watersheds in the North Central U.S. with consideration of difference among three snow classifications (Warm forest, Prairie, and Maritime). There are notable SWE differences between the SSM/I and SSMIS sensors in the Warm forest class, likely due to the different interpolation methods for brightness temperature (Tb) between the F13 SSM/I and F17 SSMIS sensors. The SWE differences between AMSR2 and AMSR-E are generally smaller than the differences between SSM/I and SSMIS SWE, based on time series comparisons and yearly mean bias. Finally, the spatial bias patterns between AMSR-E and AMSR2 versus SSMIS indicate sufficient spatial consistency to treat the AMSR-E and AMSR2 datasets as one continuous record. Our results provide useful information on systematic differences between recent satellite-based SWE retrievals and suggest subsequent studies to ensure reconciliation between different sensors in long-term SWE records.