雨季开始期变化特征及环流指标的响应  

The variation and response of circulation indicators at the start of rainy season

作　　者：李刚 杨海光 解福燕 

机构地区：[1]云南省元江县气象局,云南元江653300 [2]云南省峨山县气象局,云南峨山653200 [3]云南省玉溪市气象局,云南玉溪653100

出　　处：《云南大学学报（自然科学版）》2013年第S2期273-278,共6页Journal of Yunnan University(Natural Sciences Edition)

基　　金：由玉溪市科技局重点科研项目"初夏旱涝预测方法研究和业务系统开发应用"资助

摘　　要：统计1951—2012年干季向雨季转换后的第1次明显的降水过程资料后,制定了云南雨季开始期标准,玉溪62年来进入雨季的时间极不稳定,正常年份(5月18日前后5天)只有24.2%,特早、特晚高达75.8%,最早年与最晚年相差达到76天.分析了雨季开始期与大气环流的关系发现,头年1—4月、6—8月、10—12月500 hPa高度场部分区域对雨季早晚有较好的相关性,当马里亚纳群岛、孟加拉湾、阿拉伯海、加拿大北部、中国东海和伊朗到青藏高原高度升高,西欧北部、东西伯利亚海南岸、斯瓦尔巴群岛、欧洲伏尔加河高度降低,则雨季开始正常到偏早,反之亦然.当出现拉尼娜年,极涡偏东、西藏高压强大,则次年雨季开始正常到偏早.当出现厄尔尼诺年,极涡偏西,亚洲纬向环流偏弱,则雨季偏晚到特晚.Develop the standard of rainy season beginning time of Yunnan province by statistics of the first significant precipitation data in the period after the conversion of the dry season to the rainy season from 1952 to 2012.In the 62 years,the time of rainy season beginning of Yuxi was very unstable.Normal year(5 days before or after May 18th) only accounted for 24.2 %.75.8 % of years was too early or too late.The difference between the earliest year and the latest year was 76 days.By analysis of the relationship between the start of the rainy season and atmospheric circulation,we found that the correlation between the 500 hPa height filed of some area in January to April,June to August and October to December of previous year and the beginning of rainy season was good.When the height filed of Mariana Islands,Bay of Bengal,Arabian Sea,northern Canada,the East China Sea and Iran to the Qinghai-Tibet Plateau became higher,and the height filed of Western Europe north of the south bank of the East Siberian Sea,Svalbard,Europe Volga became lower,then the start of rainy season was normal or early,or vice versa.When the phenomenon of La Ni珘na occurred,polar vortex tended to east or Tibetan high pressure was powerful,then the start of rainy season was normal or early in next year.When the phenomenon of El Nino occurred,polar vortex tended to west or Asian zonal circulation was weak,then the start of rainy season was late or very late in next year.

关 键 词：雨季开始 变化特征 相关性 环流指标 

分 类 号：P434[天文地球—大气科学及气象学]