ABSTRACT: Characterizing the errors in satellite-based precipitation estimations for drought monitoring is of great importance, as these estimations provide both spatially and temporally complete records. The aim of this study was to evaluate satellite-based quantitative precipitation estimates to monitor meteorological drought in southwestern Iran. The reliability of the Tropical Rainfall Measuring Mission Version 7 products (3B42 and 3B43) in estimating the standardized precipitation index (SPI) was evaluated against a ground-based gridded precipitation dataset at 0.25° spatial resolution for 1998-2016. The analysis conducted for the SPI at various time scales revealed that both products (3B42 and 3B43) are capable of capturing the spatial and temporal behavior of drought events over the study region, with the best performance at SPI6. 3B43 is also more efficient in the identification of shorter severe drought events compared to 3B42. The findings suggest that both satellite products, particularly 3B43, are suitable to be used directly for SPI computation in the region for drought monitoring and early warning in terms of the accuracy and the spatial and temporal resolutions they provide.

中文翻译：

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在伊朗西南部干旱监测中评估热带降雨测量任务（TRMM）多卫星降水分析（TMPA v7）

摘要：表征用于干旱监测的卫星降水估算中的误差非常重要，因为这些估算提供了时空上完整的记录。这项研究的目的是评估基于卫星的定量降水估计量，以监测伊朗西南部的气象干旱。针对1998-2016年以0.25°空间分辨率的地面网格化降水数据集，评估了热带降雨测量任务第7版产品（3B42和3B43）在估计标准化降水指数（SPI）方面的可靠性。在不同时间尺度上对SPI进行的分析表明，两种产品（3B42和3B43）都能够捕获研究区域干旱事件的时空行为，在SPI6上表现最佳。与3B42相比，3B43在识别较短的严重干旱事件方面也更有效。研究结果表明，这两种卫星产品，特别是3B43，就其提供的准确性和时空分辨率而言，都适合直接用于该地区的SPI计算，以进行干旱监测和预警。