Meridional circulation dominates the record-breaking “Dragon Boat Water” rainfall over south China in 2022
Meridional circulation dominates the record-breaking “Dragon Boat Water” rainfall over south China in 2022
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DOI：
10.3389/feart.2022.1032313
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发表时间：
2023-01
期刊：
影响因子：
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通讯作者：
Jianbo Cheng;Yuheng Zhao;R. Zhi;G. Feng
中科院分区：
文献类型：
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作者：
Jianbo Cheng;Yuheng Zhao;R. Zhi;G. Feng
2022年“龙舟水上”期间，南中国(南加州)出现了破纪录的异常降雨。本文利用新的三型环流水汽平衡方程，对降水异常的成因进行了分析。结果表明，由水平环流、经向环流和纬向环流引起的南海降水异常分别为−10 mm、16 8 mm和45.3 mm，分别占实际降水异常(195.1 mm)的5%、86%和23%，说明经向环流对异常降水的贡献最大，纬向环流次之，水平环流负贡献。基于全球大气环流三型分解的进一步分析表明，异常水平环流和垂直涡度的空间构型为产生经向环流和纬向环流的异常辐散和辐合以及经向和纬向环流的垂直速度异常提供了背景，最终导致降水异常。
During the “Dragon Boat Water” season in 2022, record-breaking anomalous rainfall occurred over South China (SC). In this study, the causes of anomalous rainfall are investigated by using the novel moisture budget equation of three-pattern circulations. The results show that the anomalous rainfall over SC caused by the horizontal, meridional, and zonal circulations was −10 mm, 168 mm, and 45.3 mm, which contribute −5%, 86%, and 23% of the actual rainfall anomaly (195.1 mm), respectively, suggesting that the meridional circulation contributes most to anomalous rainfall, followed by zonal circulation, and horizontal circulation contributes negatively. Further analysis based on the three-pattern decomposition of the global atmospheric circulation shows that the spatial configuration of the anomalous horizontal circulation and vertical vorticity provides the background for generating the anomalous divergence and convergence of meridional and zonal circulations and further anomalous vertical velocity of the meridional and zonal circulations, ultimately resulting in anomalous rainfall.