孙婧超,管兆勇,李明刚,于亚鑫. 2018. 华南地区7-10月两类区域性极端降水事件特征及环流异常对比[J]. 气象学报, (0):-, doi:10.11676/qxxb2018.044
华南地区7-10月两类区域性极端降水事件特征及环流异常对比
Anomalous Circulation Patterns in Association with Two Types of Regional Daily Precipitation Extremes over the South China from July to October
投稿时间:2017-12-13  修订日期:2018-03-19
DOI:10.11676/qxxb2018.044
中文关键词:  华南地区,区域性日降水极端事件,环流异常,热带气旋
英文关键词:South China, regional mean daily precipitation extreme events, circulation pattern, tropical cyclones
基金项目:公益性行业(气象)科研专项(GYHY201406024)、灾害天气国家重点实验室课题2015LASW-A03以及江苏省PAPD项目
作者单位E-mail
孙婧超 南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验室 yy_jingchaosun@126.com 
管兆勇 南京信息工程大学气象灾害教育部重点实验室/气象灾害预报预警与评估协同创新中心/气候与环境变化国际合作联合实验室 guanzy@nuist.edu.cn 
李明刚 成都信息工程大学大气科学学院 leemg@nuist.edu.cn 
于亚鑫 成都信息工程大学大气科学学院 957139519@qq.com 
摘要点击次数: 336
全文下载次数: 339
中文摘要:
      利用1981-2016年7-10月中国753站逐日降水资料、MICAPS(气象信息综合分析处理系统)逐日站点降水资料、日本东京台风中心西北太平洋热带气旋(TC)最佳路径资料和NCEP/NCAR再分析资料集分析了华南地区区域性日降水极端事件(RDPE事件)的统计特征及环流异常。根据华南地区RDPE事件的发生是否受TC影响将其分为TCfree-RDPE和TCaff-RDPE两类事件,其中TCaff-RDPE事件占42%且集中发生在8月4侯至5侯;TCfree-RDPE事件以7月发生频数最多,占其总频次的1/2以上。TCfree-RDPE事件发生时,华南地区受异常气旋性环流控制,来自西太平洋和南海的暖湿气流与北方冷气团在此汇合并形成一条狭长的水汽辐合带,低层辐合、高层辐散,显著强烈的上升运动为TCfree-RDPE事件的发生与维持提供了有利条件;与此同时,波扰能量由高原东北侧及河西走廊地区向华南一带传播并在华南显著辐合,有利于华南上空扰动的发展和维持。TCaff-RDPE事件发生时,华南上空由低层到高层的斜压环流结构更为明显,异常上升运动更加强烈,TC在其运动过程中携带了大量源自孟加拉湾、南海和西太平洋地区的水汽并输送至华南地区,水汽辐合气流更为强盛。同时,波扰能量由高纬地区沿河西走廊向下游传播,但在华南地区辐合不甚明显。两类RDPE事件发生时,加热场上的差异亦明显。华南及邻近地区上空的大气净加热及其南侧大范围区域的净冷却所形成的加热场梯度对TCfree-RDPE事件的发生有利。而TCaff-RDPE事件发生时,在经向上由18°N以南、华南及其邻近地区、32°N以北呈负-正-负的异常分布型,正距平值更高,加热场梯度更大,有利于TCaff-RDPE事件的维持。这些结果有利于人们认识和预测华南RDPE事件的发生。
英文摘要:
      Using the daily precipitation data from both 753 stations in China and the Meteorological Information Comprehensive Analysis and Process System (MICAPS), the Southwest Pacific Ocean Tropical Cyclone (TC) optimal path data from the Tokyo Typhoon Center in Japan, and the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis, we have studied the statistical characteristics of regional mean daily precipitation extreme (RDPE) events and circulation anomalies in South China. Depending on whether the occurrence of a RDPE event is affected by a TC, the RDPEs are classified into two categories including TCfree-RDPE and TCaff-RDPE events. Of these, the TCaff-RDPE events are about 42% of the total RDPEs and mainly occur in late August, while the TCfree-RDPE events frequently occur in July. When TCfree-RDPE events occur, South China is controlled by abnormal cyclonic circulations, and the warm and moist airflow from the Western Pacific region and the South China Sea merge with cold air from northern in this region, inducing a long narrow zone of water vapor convergence and causing significant and strong ascending motion, in responsible for the occurrence and maintenance of TCfree-RDPE events. Simultaneously, the wave energy propagates from the northeastern side of the Tibetan Plateau and the Hexi Corridor region to South China and converges in this area, which favors the development and maintenance of perturbation over South China. Whereas, when TCaff-RDPE events occur, the southern part of China is dominated by a TC-related stronger anomalous cyclonic circulation. The warm wet air is carried into this area from the Bay of Bengal, the Western Pacific Region and the South China Sea, leading to a large amount of latent heat release over South China and inducing stronger ascending motion there. These results are helpful for our better understanding and predicting the occurrence of regional extreme precipitation events in South China.
查看全文   查看/发表评论  下载PDF阅读器
分享按钮