2021年春末夏初我国南方强对流频发的天气气候背景分析

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,.2021年春末夏初我国南方强对流频发的天气气候背景分析[J].海洋气象学报,2025,45(6)：95-105. GAO Yuan，GAN Yuting. Weatherand climate backgroundanalysisoffrequent severeconvections insouthern China inlate spring andearlysummerof2021[J].JoualofMarineMeteorology2025,45(6):95-105.DOI:10.19513/j.cnki.hyqxxb.202120001. (in Chinese)

高媛²,甘玉婷,4

关键词强对流;副热带高压；西南急流；罗斯贝波；不稳定层结

中图分类号：P458.2文献标志码：A 文章编号：2096-3599(2025)06-0095-11

DOI:10.19513/j.cnki.hyqxxb.20231220001

Weather and climate background analysis of frequent severe convections in southern China in late spring and early summer of 2021

GAO Yuan1²， GAN Yuting3,4 (1.Shanxi Instituteof Meteorological Sciences，TaiyuanO3oo02，China；2.CloudPhysics ScientificExperiment Base inMount Wutaiof China Meteorological Administration，Taiyuan O3O2，China；3.Shandong Meteorological Service Center，Jinan25Oo31，China；4.KeyLaboratoryforMeteorologicalDisasterPreventionandMitigationofShandong，Jinan 250031,China)

AbstractIn the late spring and early summer of 2O21，many areas in China experienced severe convections，causing heavy casualties and property losses，especially in southern China ( 25.0∘～32.5∘N ， （204号 112.5∘～122.5∘E ）from1O to 16 May.Through analyzing the features of the atmospheric circulation anomalies from 1O to 16 May 2021，as well as the associated dynamical，thermal and moisture conditions，the study explores the causes of frequent severe convections in southern China from the perspective of large-scale environment. The results show that the frequent severe convections are closely related to large-scale circulation anomalies.At 500hPa over Eurasia，the geopotential height anomalies exhibit a northwest-southeast oriented wave train pattern with a“ +,-,+,, distribution. Along this wave train，the Ural Mountains and the coastal areas of East Asia are dominated by positive height anomalies, while the areas from Lake Baikal to Balkhash Lake are occupied by negative height anomalies.The positiveanomalies along thecoastal areas of East Asia correspond toan intensified and northward shifted western Pacific subtropical high (shorted as WPSH). On the one hand， the anomalous southwest warm and moist airflow to the north of WPSH is beneficial to the development of ascending motion as wellas the establishment of unstable stratification in southern China.On the other hand，the pressure decrease resulting from the anomalous warm advection is favorable forthe frequent occurrence of low-level convergence systems in southern China，which provides triggering conditions for severe convections.In addition，the strong vertical wind shear formed between high-and low-level jets isalso one of the favorable dynamic conditions for the development of severe convections.Further analysis indicates that there is a southeastward propagating anomalous wave activity flux，which originates from the high latitudes of Eurasia,suggesting that the wave train-like circulation anomaly is closely assciated with the dispersion of the Rossby wave energy.Therefore,the atmospheric dynamical process in mid-high latitudes plays an important role in the frequent severe convections in southern China.

Keywordssevere convection； subtropical high ; southwesterly jet； Rossby wave; unstable stratification

0 引言

发展旺盛的对流风暴中常伴随有冰雹、雷暴大风、短时强降水、龙卷等剧烈天气，这类天气统称为强对流天气[1]。（剩余20298字）