强弱天气尺度强迫下广东短时强降水时空特征分析  

SPATIAL AND TEMPORAL CHARACTERISTICS OF SHORT-TERM HEAVY RAINFALL IN GUANGDONG UNDER STRONG AND WEAK SYNOPTIC-SCALE FORCING

作　　者：梁巧倩[1] 李晓娟[1] 文秋实 张艳霞[2] 丁伟钰[2] LIANG Qiaoqian;LI Xiaojuan;WEN Qiushi;ZHANG Yanxia;DING Weiyu(Guangdong Meteorological Observatory(Marine Weather Forecast Center of South China Sea),Guangzhou 510641,China;Guangzhou Institute of Tropical and Marine Meteorology,CMA,Guangzhou 510641,China)

机构地区：[1]广东省气象台(南海海洋气象预报中心),广东广州510641 [2]中国气象局广州热带海洋气象研究所,广东广州510641

出　　处：《热带气象学报》2022年第5期641-650,共10页Journal of Tropical Meteorology

基　　金：国家重点研发计划(2018YFC1507602);国家自然科学基金项目(42075190);广东省科技计划项目(2019B020208016、2018B020207012);雷达应用及强对流短临预警技术创新团队(GRMCTD202002)共同资助

摘　　要：利用2010—2019年广东区域自动站逐时雨量定义短时强降水日,采用500 hPa和700 hPa广东区域日平均垂直速度来客观衡量天气尺度强迫,并对年均和强/弱天气尺度强迫下的短时强降水进行时空分布特征分析,结果表明:广东区域的短时强降水主要发生在4—9月,发生频次具有准双峰的日变化;粤西是短时强降水最频发区;茂名山区的短时强降水主要发生在白天,弱天气尺度强迫下占比达80%以上;频发次中心位于珠江三角洲,持续1小时以上的短时强降水占该地发生频次75%。强天气尺度强迫下短时强降水4—6月最多,弱天气尺度强迫下则7月达到峰值。弱天气尺度强迫下,仅历时1小时的短时强降水在粤北河源-梅州北部山区、粤东莲花山脉附近有次中心;历时2小时及以上的相对集中在粤西、珠江三角洲北部和粤东惠州-汕尾一带;3月肇庆-云浮和珠江口附近弱天气尺度个例占比高;7月粤北占比高;早晨07时在粤西阳江沿海有孤立的高频中心。Hourly rainfall data from automatic stations in Guangdong Province during 2010-2019 were used to define short-term heavy rainfall days.The daily mean vertical velocity at 500 hPa and 700 hPa in Guangdong was used to objectively measure the intensity of synoptic-scale forcing.Then the spatial and temporal characteristics of two types of short-term heavy rainfall were analyzed.The results showed that the short-term heavy rainfall in Guangdong mainly occurred from April to September,and the diurnal variation frequency was quasi-bimodal.The west of Guangdong was the area with the most frequent shortterm heavy rainfall,and the short-term heavy precipitation in the mountainous area in Maoming mainly occurred in the daytime with 80%under weak synoptic-scale forcing.The center with the second highest frequency was located in the Pearl River Delta,where the short-term heavy rainfall lasting more than one hour accounted for about 75%of the local totals.Under strong synoptic-scale forcing,the short-term heavy rainfall was the most frequent from April to June,while it reached the peak in July under weak synopticscale forcing.The highest proportion of short-term heavy rainfall under weak forcing was in Zhaoqing and Yunfu and the Pearl River estuary in March,while in northern Guangdong in July.Under weak forcing,there was an isolated high-frequency center near Yangjiang in the coastal area of western Guangdong at 7:00 am.

关 键 词：短时强降水 时空分布特征 频次 强天气尺度强迫 弱天气尺度强迫 

分 类 号：P426.6[天文地球—大气科学及气象学]