大气科学学报2009，Vol.32Issue(4)：543-552,10.
初夏至盛夏东亚副热带西风急流突变早晚与东亚环流异常的关系
Relationship between Date of Abrupt Change of the East Asian Subtropical Westerly Jet and East Asian Circulation Anomaly in Early-Middle Summer
摘要
Abstract
Using the pentadly averaged NCEP/NCAR reanalysis dataset and the daily precipitation data-set of 714 stations in China from 1961 to 2004, impacts of early or late occurrence of the northward jump of East Asian subtropical westerly jet(EASWJ) and the westward movement of the EASWJ core on the East Asian circulation and the rainfall over eastern China in July are studied. The results are as follows: (1) There is closely positive correlation between the date of the northward jump of the jet and July precipitation in the middle-lower Yangtze River basin ; the date of the westward movement is posi-tively correlated with July precipitation in the Huaihe River basin, and negatively with July precipitation in North China and the Great Bend of the Huanghe River. (2) The date of the northward jump is relat-ed with the meridional locations of the South Asia high ridge and West Pacific subtropical high ridge, and the intensity of the high ridge east of the Baikal Lake; whereas the date of the westward jump is as-sociated with the east-west stretch location of the South Asia high and West Pacific subtropical high, and the intensity of the Baikal Lake high ridge. That is to say, in the later westward movement years, the South Asia high withdraws westwards, and the high ridge southwest of the Baikal Lake strengthens, transporting stronger cold air to North China and the Great Bend of the Huanghe River, meanwhile the West Pacific subtropical high withdraws eastwards, which leads to the confluence of the warm/wet and clod/dry air flows in the Huaihe River basin, bringing more rainfall in the basin and less rainfall in North China and the Great Bend region. The situation is reverse in the earlier years of the westward movement.关键词
初夏至盛夏/急流突变早晚/我国降水异常/东亚大气环流异常Key words
early-middle summer/ East Asian subtropical westerly jet/abrupt change/precipitation a-nomaly in China/East Asian circulation anomaly分类
天文与地球科学引用本文复制引用
董丽娜,郭品文,张福颖..初夏至盛夏东亚副热带西风急流突变早晚与东亚环流异常的关系[J].大气科学学报,2009,32(4):543-552,10.基金项目
国家自然科学基金资助项目(40675041) （40675041）
