摘要
利用1971—2000年NCEP/NCAR逐日再分析资料和中国730个测站逐日降水量资料,分析了江淮地区夏季典型旱、涝年水汽输送低频振荡特征及其与降水的关系。结果表明：典型涝年5-8月江淮地区的经向水汽输送有明显的30-60天低频振荡;典型旱年则不显著。江淮夏季典型涝年,热带西太平洋反气旋性低频水汽输送环流的经向（向北）传播,并与北方低频水汽输送环流在江淮地区形成暖性—冷性水汽输送的交汇,对江淮夏季降水偏多有重要作用。江淮夏季典型旱年,热带低频扰动不活跃,且未出现明显的低频水汽输送辐合北传,西太平洋反气旋性低频水汽输送环流以纬向（向西）传播为主。
Using the daily NCEP/NCAR reanalysis dataset and the observation rainfall data of China in 1971--2000, the characteristics of low-frequency oscillation （LFO） for moisture transport and its relation with rainfall during drought/flood year in the mid-and lower-reaches of Yangtze River are analyzed. Results show that obvious LFO exists in meridional moisture transport in the mid-and lower-reaches of Yangtze River during flood year while that during drought year is unnoticeable. The anti-cyclonic low-frequency moisture transport circulation over the west Pacific triggered by the northward propagation of cyclonic low-frequency circulation from the tropics interacts with the moisture transport from the north of Yangtze- Huaihe basins, which is corresponding to more rainfall during Meiyu period. On the contrary, in active low-frequency perturbation without northward propagation and the anti-cyclonic low-frequency moisture transport circulation over the west Pacific westward propagation may attribute to the less rainfall during Meiyu period.
出处
《高原气象》
CSCD
北大核心
2008年第B12期84-91,共8页
Plateau Meteorology
基金
国家自然科学基金项目(40875056)
中国气象局气候变化专项项目"华东南降水强度
极端降水对全球变暖的响应"
中国气象局新技术推广项目"低频天气系统预报技术及业务化应用"共同资助
关键词
江淮地区
水汽输送
低频振荡
旱涝
Yangtze-Huaihe Basins
Moisture transport
Low frequency oscillation
Drought and flood
