Using NCEP-NCAR reanalysis data and conventional observation data,the continuous cloudy and rainy weather process that occurred in Chenzhou City from February 1 to 14,2023,was analyzed from the aspects of circulation situation,water vapor,power,and thermal conditions.The results show that:(1)the overall circulation situation of this continuous cloudy and rainy process was two troughs and one ridge type,and the front of the blocking high pressure or nearby warm high ridge in the Ural Mountains is controlled by northwest airflow,The short wave trough in the mid latitude westerly belt drives cold air from the easterly path to the south,while the Bay of Bengal trough and the Western Pacific subtropical high transport warm and humid airflow northward,forming a long-term confrontation between cold and warm airflow.The stable maintenance of a quasi static front was the main reason for this continuous cloudy and rainy weather.(2)The southwest airflow in the middle and lower layers provides a continuous supply of water vapor for the occurrence of continuous rain,and the weak vertical upward movement causes sustained and stable rainfall.(3)During continuous rain,water vapor mainly comes from the South China Sea,Bay of Bengal,and Western Pacific.The occurrence of continuous rain does not necessarily require strong water vapor flux convergence,and continuous water vapor supply was relatively more important.(4)The continuous cloudy and rainy process was formed due to the influence of cold air evolving into a quasi stationary front.During the continuous cloudy and rainy period,the stationary front area remained at 25 to 30°N,with a large north-south range of the front area and stable with little movement,which was conducive to the maintenance of continuous cloudy and rainy weather.
关键词
连阴雨/环流形势/天气过程
Key words
Persistence Rainy Days/Circulation Analyses/weather process
维普
万方数据