江淮流域夏季低频降水的前期预报信号
投稿时间: 2018-02-27  最后修改时间: 2018-05-03  点此下载全文
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作者单位E-mail
韩世茹 河北省气候中心 hanshiru615@163.com 
王黎娟 南京信息工程大学 wljfw@163.com 
周须文 河北省气候中心  
基金项目:公益性行业(气象)科研专项(GYHY201406001);江苏省高校自然科学研究重大项目(14KJA170004);国家自然科学基金(41575081);国家自然科学基金项目(面上项目,重点项目,重大项目)
中文摘要:本文基于ECMWF提供的ERA-Interim逐日4时次再分析资料和中国气象局提供的753站逐日降水资料,对1980-2013年江淮流域夏季降水特征进行分析,探究江淮流域夏季低频降水的前期预报信号,结果表明:1)江淮流域夏季降水受10-30天低频振荡影响显著,10-30天低频分量在江淮流域夏季降水中占较大比重。2)200hPa上,低频降水过程发生前9-6天有低频反气旋(低频气旋)自青藏高原东北部向中国东部移动。500hPa上超前低频降水过程9天至低频降水过程发生时有西太副高自东向西(自西向东)移动至中国东部沿海地区,热带地区负(正)低频OLR中心不断向北移动,最北端到达江淮流域并达到最强,进而促进(抑制)江淮流域低频降水的发生。3)青藏高原预报信号能够有效补充西太副高及热带OLR信号的不足,将青藏高原信号、西太副高信号及热带OLR信号作为综合预报因子对江淮流域降水进行预报,对仅依赖低纬度地区信号进行降水过程预报的准确率有较好改进作用。
中文关键词:江淮流域  低频降水  青藏高原  预报因子
 
Forecast Signal of Summer Low-frequency Precipitation in Yangtze-Huaihe River Basin
Abstract:Based on ERA-Interim reanalysis data of four times a day provided by ECMWF and daily precipitation data from 753 stations provided by China Meteorological Administration, the characteristics of summer precipitation in Yangtze-Huaihe river basin from 1980 to 2013 are analyzed. The forecast signal of summer low-frequency precipitation in Yangtze-Huaihe river basin is explored. The results show that: 1) The 10-30 days low frequency precipitation which occupies a large proportion in the summer precipitation can influence the summer precipitation over the Yangtze-Huaihe river basin. 2) At 200hPa, there is a low-frequency anticyclone moving from the northeast of the Tibetan Plateau to the eastern China in 9-6 day before the low-frequency precipitation process occurred. At 500hPa, the Western Pacific Subtropical High moved from east to west reaches the eastern coastal areas of China during 9 days before the occurrence of low-frequency precipitation process. The center of negative low frequency OLR in the tropics moves northward and reaches the strongest when its northernmost reaches the Yangtze-Huaihe river basin. The above circulation distribution will promote the occurrence of the low-frequency precipitation in the Yangtze-Huaihe river basin, or the vice versa. 3) The Tibetan Plateau prediction signal can effectively supplement the deficiency of the West Pacific Subtropical High and the tropical OLR signal. The accuracy of precipitation process prediction relying only on the low latitude signals can be improved by using the Tibetan Plateau Signal, Western Pacific Subtropical High Signal and Tropical OLR Signal as comprehensive predictors.
keywords:Yangtze-Huaihe river basin  low-frequency oscillation precipitation  the Tibetan Plateau  predictor
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