中国东部夏季极端降水统计特征及其与ElNiño的联系
投稿时间: 2015-10-27  最后修改时间: 2016-01-01  点此下载全文
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作者单位E-mail
余锦华 南京信息工程大学 气象灾害教育部重点实验室, 江苏 南京 210044 jhyu@nuist.edu.cn 
祁淼 南京信息工程大学 气象灾害教育部重点实验室, 江苏 南京 210044  
孙齐颖 民航江苏空管分局气象台, 江苏 南京 211113  
陶丽 南京信息工程大学 气象灾害教育部重点实验室, 江苏 南京 210044  
基金项目:国家自然科学基金资助项目(41630423;41575083);江苏省高校自然科学研究重大项目(13KJA170002);江苏高校优势学科建设工程项目(PAPD)
中文摘要:选取中国东部1961—2012年夏季5—9月无缺测429站逐日降水资料,利用广义帕雷托分布(GPD)拟合,研究中国东部52 a以及El Niño发展年和衰减年极端降水的统计特征,并分析其成因。结果表明:1)中国东部降水阈值呈由东南向西北递减的态势,且基本为线性增加趋势。2)华南地区尺度参数最大,出现极端降水的概率大。黄河以南地区尺度参数变化趋势正值较多,出现极端降水的概率增加。3)El Niño发展年夏季,西太平洋上有气旋环流异常,中国东南部受气旋西侧的异常偏北气流影响,多地阈值偏小,只有福建东南部及黑龙江中西部易发生破纪录的极端降水。4)El Niño衰减年夏季,西太平洋上为异常反气旋环流,中国东南部受反气旋西侧的异常偏南气流影响,多地阈值偏大,广东中东部及皖鄂赣交界处发生洪涝灾害的可能性增大。
中文关键词:中国东部  极端降水  统计特征  El Niño  GPD
 
Statistical characteristics of summer extreme rainfall over eastern China and its relation with El Niño
Abstract:China is located in an area of complex climate in Asia.Its rainy season mainly appears in summer.And the frequent floods caused by extreme rainfalls have brought serious impacts and heavy losses to the economic development and people’s lives.So it is necessary to know the temporal and spatial distribution of the extreme rainfalls in Eastern China.At present,there are many probability models on extreme value theory research.Among these models,the Generalized Pareto Distribution(GPD) is often used by researchers to study extreme rainfalls.In this paper,based on the daily rainfall data from 429 stations with no missing over Eastern China from May to September during 1961 and 2012,GPD is used to study the spatial distribution of extreme rainfall statistical characteristics in these 52 years,as well as in El Niño developing and decaying years.The causes of the extreme rainfalls are also discussed.The results show that:(1)The thresholds decrease roughly from southeast to northwest.And the largest value of the thresholds is in southern Guangdong,which means there are more rainfalls in summer there than other places.Besides,southern Guangdong is close to the Pearl River,which leads to higher probabilities of flood disasters in summer.The trends of thresholds are basically positive over Eastern China.(2)The largest values of scale parameter are in South China,which means there are higher probabilities of maximum rainfalls.The trends of scale parameter are positive in most places to the south of the Yellow River.And the probabilities of maximum rainfalls are increasing in these places.Besides,thresholds and the trends of scale parameter of the stations located along the Yangtze River are large.So we should pay great attention to the flood disasters occurring in these places.(3)In the summer of El Niño developing years,there is cyclone circulation anomaly in western Pacific.And the Southeast China is under the influence of north wind anomaly on the west of the cyclone,which leads to less rainfalls in most places over Eastern China.The values of scale parameter are smaller in most places in the north area than usual,especially in Neimenggu.In these places,the probabilities of maximum rainfalls are limited.There are more probabilities of record-breaking maximum rainfalls only in southeastern Fujian and west central Heilongjiang.(4)In El Niño decaying years,there is anticyclone circulation anomaly in western Pacific.The Southeast China is under the influence of south wind anomaly on the west of the anticyclone.And the area of west Pacific subtropical high is large,which leads to more rainfalls in most places over Eastern China.The values of scale parameter are larger in most places over Eastern China than usual,except in northwestern Heilongjiang,west-central Neimenggu,southern Hebei,northern Jiangsu,southern Yunnan and so on.The probability of severe flooding disasters is large in east central Guangdong and at the junction of Anhui,Hubei,and Jiangxi.
keywords:Eastern China  extreme rainfall  statistical characteristic  El Niño  GPD
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