Assessing the Reliability of Satellite and Reanalysis Estimates of Rainfall in Equatorial Africa
Assessing the Reliability of Satellite and Reanalysis Estimates of Rainfall in Equatorial Africa
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DOI：
10.3390/rs13183609
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发表时间：
2021-09
期刊：
影响因子：
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通讯作者：
S. Nicholson;D. Klotter
中科院分区：
文献类型：
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作者：
S. Nicholson;D. Klotter
本文审查了对刚果盆地和维多利亚湖及其集水区上空降雨量的卫星和再分析估计的可靠性。考虑了9个卫星产品和5个再分析产品。它们是通过相互比较和与观测数据集的比较来评估的。审议的三个地点包括一个观测站数据很少的地区(刚果)、一个有大量监测站数据的地区(维多利亚湖流域)和一个内陆水体。出现了几个重要的结果：首先，除了维多利亚湖集水区外，估计的差异通常非常大。再分析产品与观测降雨量或卫星估计值几乎没有关系，因此不应用于评估这些地区的降雨量。大多数产品要么高估了湖上的降雨量，要么低估了降雨量。由于估计数字的多样性，很难评估影响这些地区降雨量年际变化的因素。这表现为与海面温度的相关性，特别是与尼诺3.4温度和印度洋上空偶极子模式指数的相关性。对于最好的产品，给出了一些指导意见。总体而言，任何用户都必须确定产品在所研究的地区是可靠的。
This article examines the reliability of satellite and reanalysis estimates of rainfall in the Congo Basin and over Lake Victoria and its catchment. Nine satellite products and five reanalysis products are considered. They are assessed by way of inter-comparison and by comparison with observational data sets. The three locations considered include a region with little observational gauge data (the Congo), a region with extensive gauge data (Lake Victoria catchment), and an inland water body. Several important results emerge: for one, the diversity of estimates is generally very large, except for the Lake Victoria catchment. Reanalysis products show little relationship with observed rainfall or with the satellite estimates, and thus should not be used to assess rainfall in these regions. Most of the products either overestimate or underestimate rainfall over the lake. The diversity of estimates makes it difficult to assess the factors governing the interannual variability of rainfall in these regions. This is shown by way of correlation with sea-surface temperatures, particularly with the Niño 3.4 temperatures and with the Dipole Mode Index over the Indian Ocean. Some guidance is given as to the best products to utilize. Overall, any user must establish that the is product reliable in the region studied.