Record-Breaking Meiyu Rainfall Around the Yangtze River in 2020 Regulated by the Subseasonal Phase Transition of the North Atlantic Oscillation
Record-Breaking Meiyu Rainfall Around the Yangtze River in 2020 Regulated by the Subseasonal Phase Transition of the North Atlantic Oscillation
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DOI：
10.1029/2020gl090342
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发表时间：
2020-11-28
影响因子：
5.2
通讯作者：
Li, Jianying
中科院分区：
文献类型：
--
作者：
Liu, Boqi;Yan, Yuhan;Li, Jianying
2020年，长江遭遇了持续时间较长的梅雨期。累积降雨量打破了自1961年以来的记录，并在中国造成严重的洪水和死亡。结果表明，北大西洋涛动（NAO）控制下的冷暖梅雨锋序列是造成这次异常梅雨的主要原因。6月11 ~ 25日，在北大西洋涛动为正值的情况下，南亚高压与西太平洋副热带高压的相互作用维持了一个暖锋，加强了长江以北的雨带。随后，南亚高压与中纬度蒙古气旋耦合形成冷锋，使6月30日至7月13日的云顶雨带向南黄海南部后撤，并伴有负北大西洋涛动。ECMWF的S2 S模式虽然成功地预报了与暖锋相关的梅雨带，但未能预报冷锋期的梅雨带，这给S2 S模式的梅雨预报带来了很大的挑战。
In 2020, the Yangtze River (YR) suffered a long-persisting Meiyu season. The accumulated rainfall broke its record since 1961 and caused severe flooding and death in China. Our results show the sequential warm and cold Meiyu front regulated by the North Atlantic Oscillation (NAO) was responsible for this unexpected extreme Meiyu event. From 11 to 25 June with the positive NAO, the interaction between the South Asian High (SAH) and the western Pacific subtropical high maintained a warm front to strengthen the rainband north of the YR. Afterward, the coupling between SAH and midlatitude Mongolian Cyclone induced a cold front, which retreated the rainband to the south of YR from 30 June to 13 July with the negative NAO. Although the ECMWF S2S model successfully predicted the warm-front-related Meiyu rainband, it failed to forecast the Meiyu rainband in the cold-front period, suggesting a great challenge of S2S forecasting on Meiyu rainfall.