气象研究与应用2024，Vol.45Issue(2)：102-108,7.DOI:10.19849/j.cnki.CN45-1356/P.2024.2.17
2023年6月一次北部湾低压极端暴雨过程天气气候特征
Weather and climate characteristics of an extreme rainstorm process caused by a tropical depression in the Beibu Gulf in June,2023
摘要
Abstract
The weather and climate characteristics of the persistent extreme rainstorm process of a depression in the Beibu Gulf from 7 to 10 June 2023 were studied using daily reanalysis data.The results show that:(1)the subtropical high was abnormally north-westerly and in a stable position during the pre-and period of the persistent extreme rainstorm.The tropical convergence zone along the Bay of Bengal-South China Sea-Philippines was active,and a low-pressure system was generated in the western part of the South China Sea and moved into the Beibu Gulf.(2)The intra-seasonal oscillation(MJO)was in the 2nd and 3rd phases,influenced by its eastward transmission,and the position of the trough-ridge formed by the mid-and high-latitude circulation was favourable for cold air to move southward to affect Guangxi.There was a northeast low-vortex maintaining near the northeastern China at 500 hPa,and the strong northerly wind behind this vortex guided the cold air to the south,which was blocked by the north-westerly subtropical high,causing a small cold-air infiltration to affect Guangxi to the south.(3)The trans-equatorial airflow in the Indian Ocean and the southwesterly monsoon were strong at 850 hPa in the lower layers,but their activities were skewed to the south,and the southwesterly jets of the Indian Ocean-Central South Peninsula-South China Sea was blocked by Typhoon Guchol and shifted into southerly winds,which led to the cyclonic convergence of the airflow around the Beibu Gulf.There is a weak northeasterly wind in northwestern Guangxi,which enhanced the cyclonic convergence of the airflow around Beibu Gulf.(4)The southern part of Guangxi and the Beibu Gulf area were located to the right of the 200 hPa East Asian subtropical high-level jet stream and to the left of the 850 hPa southwesterly jet streams,with high-level divergence and low-level convergence,and abundant water vapour conditions in the 1 000～300 hPa water vapour flux convergence zone.Overall,the above collaborative effect of the mid-and low-latitude weather systems provided a favourable and stable large-scale circulation background,as well as adequate thermal and dynamical conditions for this persistent extreme rainstorm.关键词
持续性极端暴雨/北部湾低压/副热带高压/高低空急流Key words
persistent extreme rainstorm/depression in the Beibu Gulf/subtropical high/high-and low-level jets分类
天文与地球科学引用本文复制引用
何慧,赖晟,郑凤琴,刘璐..2023年6月一次北部湾低压极端暴雨过程天气气候特征[J].气象研究与应用,2024,45(2):102-108,7.基金项目
广西重点研发计划项目(桂科AB21075008)、国家自然科学基金项目(42065004) （桂科AB21075008）
