Out-of-phase relationships between convection over northwest India and warm pool region during the winter season

CORC > 南海海洋研究所 > 中国科学院南海海洋研究所 > 海洋科技动态信息-印太暖池系统研究

	Out-of-phase relationships between convection over northwest India and warm pool region during the winter season
	Yadav, RK ; Kumar, KR ; Rajeevan, M
刊名	INTERNATIONAL JOURNAL OF CLIMATOLOGY
	2009
卷号	29 期号:9 页码:1330-1338
关键词	warm pool western disturbances winter precipitation northwest India Madden-Julian oscillation Rossby-gyre dynamics
ISSN号	0899-8418
通讯作者	yadav@tropmet.res.in
中文摘要	In this paper, we investigate the effect of convection over warm pool region of Indonesia on northwest India winter precipitation (NWIWP) using an analysis of latest available observed climate data. The analysis is based on correlations and composites performed using India Meteorological Department (IMD) records of station data. We find that there is an out-of-phase relationship between convection over warm pool region and northwest India during the winter season. In particular, a positive precipitation anomaly over northwest India is typically found in correspondence to subdued convection over warm pool region. A physical mechanism for such effect is proposed, by which during excess years of NWIWP the tropical cooling over the warm pool region due to Suppressed convection generates an Upper-level convergence (cyclonic circulation) anomaly over South Asia which intensifies the westerly jet stream over Indian region. Also, the reduced convection over the warm pool may be due to reduced Madden-Julian oscillation (MJO) activities on the intra-seasonal timescale. The Rossby-gyre dynamics with the strong vertical and westward meridional tilts in the tropical baroclinic atmosphere forms cyclonic circulation anomalies at the upper troposphere due to a weak MJO which intensifies the westerly jet stream over the Indian region. The jet stream guides the western disturbances (WDs) and hence increases precipitation over northwest India. The seasonal persistence in migration of convective maximum from south Asia (foothills of the Himalayas) to Indonesia during the peak months of boreal summer to winter increases the seasonal predictability of NWIWP. Copyright (C) 2008 Royal Meteorological Society
学科主题	Meteorology & Atmospheric Sciences
收录类别	SCI
原文出处	JOHN WILEY & SONS LTD
公开日期	2011-07-14
内容类型	期刊论文
源URL	[http://ir.scsio.ac.cn/handle/344004/8415]
专题	南海海洋研究所_海洋科技动态信息-印太暖池系统研究
推荐引用方式 GB/T 7714	Yadav, RK,Kumar, KR,Rajeevan, M. Out-of-phase relationships between convection over northwest India and warm pool region during the winter season[J]. INTERNATIONAL JOURNAL OF CLIMATOLOGY,2009,29(9):1330-1338.
APA	Yadav, RK,Kumar, KR,&Rajeevan, M.(2009).Out-of-phase relationships between convection over northwest India and warm pool region during the winter season.INTERNATIONAL JOURNAL OF CLIMATOLOGY,29(9),1330-1338.
MLA	Yadav, RK,et al."Out-of-phase relationships between convection over northwest India and warm pool region during the winter season".INTERNATIONAL JOURNAL OF CLIMATOLOGY 29.9(2009):1330-1338.