近日，国防科技大学马占宏团队研究了热带气旋强度、平动速度和环境垂直风切变对降水不对称的影响。2025年9月2日出版的《中国科学：地球科学》杂志发表了这项成果。

热带气旋降水是严重自然灾害的主要特征。研究组分析了2001 - 2020年热带气旋强度、平动速度和垂直风切变对降水不对称主题卫星降水资料、ERA5再分析数据和IBTrACS最佳轨迹资料的影响。结果表明，热带气旋不对称性随着风暴强度的增加而逐渐减弱，而随着平动速度和垂直风切变的增加而增强。定量分析表明，与平动速度相比，垂直风切变对降水不对称的调节作用更为关键。这三个因素分别影响暴雨降水，又相互调节。具体来说，逆行垂直风切变抑制了风暴强度。这种抑制随着垂直风切变的增强和垂直风切变方向与风暴运动方向的绝对夹角增大而更加明显。

与之对应的是，热带气旋在正向垂直风切变下的降水比反向强。与强度抑制机制不同，除右后垂直风切变外，高垂直风切变条件下的雨率始终高于低垂直风切变条件下的雨率。综合分析表明，降水偏好和最强降水通常位于下切变左侧。然而，当切变相对于风暴运动朝向左后方时，强后向垂直风切变减弱的气旋环流将降水输送到左下切变的能力降低。在这种情况下，似乎风暴运动产生的降雨的正向偏好主导了降水结构。降水偏好和最强降水均位于下切变右侧。

附：英文原文

Title: Investigating the effects of tropical cyclone intensity, translation speed, and environmental vertical wind shear on precipitation asymmetry

Author: Lihao CHEN, Zhanhong MA, Jianfang FEI

Issue&Volume: 2025/09/02

Abstract: Tropical cyclone precipitation is a major cause of severe natural hazards. This study analyzes the influence of tropical cyclone intensity, translation speed, and vertical wind shear on precipitation asymmetry using satellite precipitation data, ERA5 reanalysis dataset, and IBTrACS best track data from 2001 to 2020. Results reveal that tropical cyclone asymmetry gradually weakens with increasing storm intensity while it strengthens with higher translation speed and vertical wind shear. Quantitative analysis indicates a more critical role of vertical wind shear in modulating precipitation asymmetry compared to translation speed. These three factors affect storm precipitation individually, and also modulate each other. Specifically, storm intensity is suppressed under backward vertical wind shear. This suppression becomes more pronounced as the vertical wind shear enhances and the absolute angle between vertical wind shear direction and storm motion direction increases. Correspondingly, tropical cyclones exhibit stronger precipitation under forward vertical wind shear than backward. Unlike the intensity suppression mechanism, the rain rates under high vertical wind shear are consistently higher than those under low, with the exception of backward right vertical wind shear. Composite analyses demonstrate that the rainfall preference and the heaviest precipitation are typically located to downshear left. Nevertheless, when the shear is directed towards the rear left relative to the storm motion, the weakened cyclonic circulation under strong backward vertical wind shear reduces its capacity to transport precipitation to the downshear left. In this case, it appears that the forward preference of the rainfall generated by storm motion dominates the precipitation structure. The rainfall preference and the heaviest precipitation are both located to downshear right.

DOI: 10.1007/s11430-024-1651-2

Source: https://www.sciengine.com/10.1007/s11430-024-1651-2