The Drought Events over the Amazon River Basin from 2003 to 2020 Detected by GRACE/GRACE-FO and Swarm Satellites
The Drought Events over the Amazon River Basin from 2003 to 2020 Detected by GRACE/GRACE-FO and Swarm Satellites
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DOI：
10.3390/rs14122887
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发表时间：
2022-06-01
期刊：
影响因子：
5
通讯作者：
Lin, Xu
中科院分区：
文献类型：
--
作者：
Cui, Lilu;Yin, Maoqiao;Lin, Xu
亚马逊河流域（ARB）气候异常对全球气候变化有着非常重要的影响，一直是各国科学家关注的焦点。为了填补重力恢复与气候实验（GRACE）和GRACE后续（GRACE-FO）任务之间11个月的数据空白，采用广义三角帽和最小二乘法融合6个GRACE解的TWSC结果，以提高TWSC结果的可靠性，并结合Swarm数据构建基于TWSC的干旱指数（GRACE/Swarm-DSI）的不间断长时间序列。干旱指数被用来检测和表征干旱事件在ARB之间的2003年和2020年。结果表明，GRACE/Swarm-DSI与自校正帕尔默干旱指数（SCPDSI）有较强的相关性（0.6345），标准化降水蒸散指数-3（SPEI-3）（0.5411），SPEI-6（0.6377）和SPEI-12 GRACE/Swarm-DSI与上述4个干旱指数的Nash-Sutcliffe效率分别为0.3348、0.2786、0.4044和0.4627。在研究期间，ARB确定了11次干旱事件，2005年，2010年和2016年的干旱是最严重和最长的。GRACE/Swarm-DSI与降水量（PPT）的相关性（延迟2个月相关系数为0.55）高于与蒸散量（ET）的相关性（延迟12个月相关系数为-0.18）。这说明PPT的减少是ARB干旱事件的主要原因。在大部分地区，GRACE/Swarm-DSI对PPT的响应时间为1 ~ 2个月。研究结果为Swarm模型在水文应用中填补GRACE与GRACE-FO之间的差距提供了一定的参考。
The climate anomaly in the Amazon River basin (ARB) has a very important influence on global climate change and has always been the focus of scientists from all over the world. To fill the 11-month data gap between Gravity Recovery and Climate Experiment (GRACE) and GRACE Follow-On (GRACE-FO) missions, we fused the TWSC results from six GRACE solutions by using the generalized three-cornered hat and the least square method to improve the reliability of TWSC results, and then combined Swarm data to construct an uninterrupted long time series of a TWSC-based drought index (GRACE/Swarm-DSI). The drought index was used to detect and characterize the drought events in the ARB between 2003 and 2020. The results show that GRACE/Swarm-DSI has a strong correlation with Self-Calibrating Palmer Drought Severity Index (SCPDSI) (0.6345), Standardized Precipitation Evapotranspiration Index-3 (SPEI-3) (0.5411), SPEI-6 (0.6377) and SPEI-12 (0.6820), and the Nash-Sutcliffe efficiency between GRACE/Swarm-DSI and the above four drought indices are 0.3348, 0.2786, 0.4044 and 0.4627, respectively. Eleven drought events were identified in the ARB during the study period, and the 2005, 2010 and 2016 droughts are the most severe and the longest. The correlation between GRACE/Swarm-DSI and precipitation (PPT) (the correlation coefficient is 0.55 with a 2-month delay) is higher than that of evapotranspiration (ET) (the correlation coefficient is -0.18 with a 12-month delay). It explains that less PPT is the main cause of drought events in the ARB. The influence of PPT is greater in the plains than the one in the mountains and the response time of GRACE/Swarm-DSI to PPT is 1 similar to 2 months in most regions. Our results provide a certain reference for the hydrological application of the Swarm model in filling the gap between GRACE and GRACE-FO missions.