摘要
基于中国气象局1961~2018年地面降水日值格点(0.5°×0.5°)数据集(V2.0)及位势高度、风速、比湿等NCEP/NCAR逐日再分析资料,采用百分位阈值法确认江南区域性极端降水事件,并对其天气图进行综合分析提取锋面型和气旋型极端降水,并对两类极端降水的时空分布及环流演变特征进行了对比。结果表明:(1)锋面型极端降水事件主要分布在春季,而气旋型主要分布在夏季,并且锋面型极端降水事件发生频率约为气旋型的3倍;(2)锋面型极端降水主要分布于武夷山脉、南岭等地势较高地区,而气旋型则位于东南沿岸地区,福建等地受两类极端降水影响都较大;(3)锋面型和气旋型极端降水发生前两天至当天,气流垂直上升速度均增大,副高西移,锋面型极端降水的最大水汽辐合中心由江南地区850 hPa等压面降至地表,而气旋型的水汽辐合中心位于地表由南向北移至江南地区;(4)锋面型极端降水形成所需的水汽主要来源于西太平洋、印度洋和孟加拉湾,汇合于江南地区,而气旋型水汽主要来源于印度洋,并呈涡旋型随时间西移。
In this paper,based on the daily precipitation dataset of grid points(0.5°×0.5°)of version 2 during 1961-2018 from China Meteorological Administration and NCEP/NCAR daily reanalysis dataset such as potential height,wind speed,specific humidity and so on,the percentile threshold method is adopted to confirm regional extreme precipitation events of Jiangnan area,and the comprehensive analysis of weather maps are extracted frontal and cyclonic extreme precipitation,and the temporal and spatial distribution and circulation evolution characteristics of those are compared.The results show that:(1)Frontal extreme precipitation is mainly distributed in the spring,while the cyclonic extreme precipitation is mainly distributed in the summer,and the frequency of frontal extreme precipitation is about three times of that of the cyclones.(2)Frontal extreme precipitation is mainly distributed in Wuyi mountain range,Nanling and other higher areas,while the cyclonic type is located in the southeastern coastal region,and places such as Fujian are greatly affected by both types of extreme precipitation.(3)From two days before the occurrence of frontal and cyclonic extreme precipitation to the same day of them,the vertical ascending velocity of airflow increases,and the subtropical high moves to the west.The maximum water vapor convergence center of frontal extreme precipitation dropped from the 850 hPa isobaric surface in Jiangnan area to the surface,while the center of cyclonic extreme precipitation moved from south to north to Jiangnan area.(4)The water vapor required by frontal extreme precipitation mainly comes from the western Pacific Ocean,Indian Ocean and bay of Bengal,and converges in Jiangnan,while the cyclonic water vapor mainly comes from the Indian Ocean,and moves westward with time in a vortex pattern.
作者
陈晓红
张新主
章新平
龙浠玉
CHEN Xiao-hong;ZHANG Xin-zhu;ZHANG Xin-ping;LONG Xi-yu(College of Resources and Environmental Science,Hunan Normal University,Changsha 410081,China;Key Laboratory of Geospatial Big Data Mining and Application,Changsha 410081,China)
出处
《长江流域资源与环境》
CAS
CSSCI
CSCD
北大核心
2020年第11期2530-2540,共11页
Resources and Environment in the Yangtze Basin
基金
国家自然科学基金(41571021)
湖南省一流学科(地理)项目(810006)
湖南省教育厅项目(14C0714)
湖南师范大学博士启动基金(120512)。
关键词
区域性极端降水
锋面型
气旋型
江南地区
regional extreme precipitation
frontal
cyclonic
Jiangnan area
