热带气象学报2017，Vol.33Issue(5)：588-597,10.DOI:10.16032/j.issn.1004-4965.2017.05.002
1998年长江流域二度梅建立过程中西太平洋副热带高压异常调整的机制分析
MECHANISM STUDY FOR ANOMALOUS VARIATION OF THE WESTERN PACIFIC SUBTROPICAL HIGH DURING THE REBUILDING PROCESS OF THE MEIYU OVER THE YANGTZE RIVER VALLEY IN 1998
摘要
Abstract
Based on the NCEP Reanalysis 2 data,the variation of geopotential heights during the rebuilding process of the Meiyu over the Yangtze River valley in July 1998 is analyzed by using the linear geopotential equation.It is revealed that the rebuilding of the Meiyu is due to the southward retreat and enhancement of the western Pacific subtropical high (WPSH),which is mainly characterized by respective decrease and increase of geopotential heights in the northern and southem part of the WPSH.This process consists of two stages,i.e.,the first stage of decreasing and southwardretreating,and the second stage of increasing and maintaining.Moreover,the weather systems in high and low latitudes play a collective role in the adjustment process.The vorticity-related geostrophic mode and the friction divergence are the two most important items.Specifically,without considering the boundary effect,the former's contribution order is 101 gpm and the latter's is 100 gpm,yet with the contribution constrained to the lower level of the troposphere.Due to deep depression troughs induced by Rossby waves in the middle and high latitudes,the geopotential height to the north of WPSH tends to decrease persistently under the impact of a vorticity-related geostrophic mode.Similarly,it is also this item that makes geopotential heights to the south turn to increase after reaching a minimum because of the northward movement of an equatorial anticyclone.Through positive feedback,the friction divergence item tends to accelerate the aforementioned decrease and increase trends.关键词
线型位势诊断方程/二度梅/西太平洋副热带高压/双脊线Key words
linear geopotential equation/rebuilding of the Meiyu/western Pacific subtropical high/double ridgelines分类
天文与地球科学引用本文复制引用
苏同华,吕思思,袁卓建..1998年长江流域二度梅建立过程中西太平洋副热带高压异常调整的机制分析[J].热带气象学报,2017,33(5):588-597,10.基金项目
国家自然科学基金青年科学基金项目(41405056) （41405056）
福建省自然科学基金青年创新项目(2015J05078) （2015J05078）
华东区域气象科技协同创新基金合作项目(QYHZ201405)共同资助 （QYHZ201405）
