华北地区一次秋季连阴雨过程分析  

Analysis of a Continuous Rainy Process in Cutumn in North China

作　　者：王楠 刘炳杰 WANG Nan(Cangzhou Meteorological Bureau,Cangzhou,Hebei 061001)

机构地区：[1]沧州市气象局,河北沧州061001

出　　处：《农业灾害研究》2022年第9期126-128,共3页Journal of Agricultural Catastrophology

摘　　要：利用自动站观测资料、ERA5再分析资料和雷达资料,对2021年10月3—7日华北沧州地区一次连阴雨过程环流背景、物理量场进行分析。结果表明:100 hPa南亚高压和200 hPa副热带西风急流异常偏北利于雨带北跳;500 hPa上乌拉尔山高压脊、副热带高压及巴尔喀什湖低压较常年平均异常偏强,维持稳定降水形势;850 hPa切变线及近地面阻高利于低层长时间冷暖空气交汇。此次过程水汽来自西太平洋西部和南海海域,水汽通量分布上沧州地区水汽条件很好;中低层比湿和风场对降水强度演变有一定影响。过程前期,整层上升运动有利于触发中低层条件不稳定,导致对流性降水;后期,近地面偏东风回流冷却和中低层持续上升造成稳定性锋面降水,同时近地面风场变化对于连阴雨起止时间有一定指示意义。Based on the conventional automatic station observation data,ERA5 reanalysis grid data and radar data,analyzing the Circulation background,physical field characteristics of a continuous rainstorm process in Cangzhou area of North China from October 3 to 72021 is analyzed in detail.The result shows that,100 hPa South Asian High and 200 hPa subtropical westerly jet anomalous northward bound to rain belt north jump.On 500 hPa,the high ridge of the Ural Mountains,the subtropical high and the low pressure of the Lake Balkhash are stronger than the normal average,maintaining a stable precipitation situation.During the precipitation period,the shear line at 850 hPa and the near-ground blocking high are conducive to the long-term cold and warm air convergence in the lower layer.The water vapor in this process comes from the western of Western Pacific and the South China Sea.The water vapor flux map shows that the water vapor condition in Cangzhou is good.Influence of specific moisture and Wind field on the evolution of precipitation intensity.The whole-layer ascending motion in the early stage of the process is conducive to triggering the instability of the middle and lower levels,resulting in convective precipitation;late near-ground easterly return cooling and lowlevel continuous upward movement caused stable front precipitation.at the same time the near-ground wind change has certain indicative significance for the start or end time of continuous rain.

关 键 词：秋季连阴雨 环流场异常 低层风场演变 物理量场特征 

分 类 号：P426.6[天文地球—大气科学及气象学]