摘要
参照北美研究低空急流气候特征的方法,对中国低空急流进行重新定义,实现了低空急流定义的统一,并在此基础上对低空急流活动特征进行了分析。结果表明:中国低空急流主要有两个活动中心,分别位于江南地区和东北地区;江南地区的低空急流活动主要有两个活跃期,分别为1—4月和6—7月;东北地区的低空急流活动主要表现为2月、8—9月两个活动较弱期;江南地区的低空急流主要在6—8月表现出独立的急流轴,东北地区则主要在8月份;汛期低空急流活动与长江流域区域性暴雨有伴随性,多雨年急流次数很多,少雨年则很少;长江中下游及两湖盆地附近急流活动有明显的日变化。
Based on the method used in studies of LLJ in North America,A new definition of LLJ in China is given,and the characteristics of LLJ activity are discussed.Results show that there are two LLJ centers locating in Jiangnan and Dongbei respectively;The Jiangnan LLJ is relatively active during January-April and June-July,but the Dongbei LLJ is inactive in February and during August-September;An independent LLJ axis exists from June to August in Jiangnan,but in August in Dongbei;The regional torrential rain in the Yangtze river basin is closely associated with the LLJ during the major rainfall period,and the year with high (low) frequency of LLJ corresponds to a surplus (deficit) precipitation.It is also found that the LLJ in the Yangtze river basin exhibits evident diurnal variation.
出处
《南京气象学院学报》
CSCD
北大核心
2003年第6期797-805,共9页
Journal of Nanjing Institute of Meteorology
基金
国家重点基础研究发展规划项目(G1998040907-02-01)
关键词
低空急流
急流观测
气候特征
急流轴
low level jet
statistic feature
number of occurrence of jet
