干旱区生态环境知识资源中心(Arid): A Diagnostic Study of Heavy Rainfall in Karachi Due to Merging of a Mesoscale Low and a Diffused Tropical Depression during South Asian Summer Monsoon

Arid

DOI	10.1007/BF02918751
	A Diagnostic Study of Heavy Rainfall in Karachi Due to Merging of a Mesoscale Low and a Diffused Tropical Depression during South Asian Summer Monsoon
	Ghulam RASUL; Qamar-uz-Zaman CHAUDHRY; Zhao Sixiong; Zeng Qingcun; Qi Linlin; Zhang Gaoying
来源期刊	Advances in Atmospheric Sciences
ISSN	0256-1530
出版年	2005
卷号	22 期号:3 页码:375-391
英文摘要	This paper presents the results of a diagnostic study of a typical case of very heavy rainfall during the South Asian summer monsoon when a mesoscale low in a desert climate merged with a diffused tropical depression. The former low was located over Pakistan's desert region and the latter depression originated over the Bay of Bengal. Surface and NCEP reanalysis data supported by satellite and radar images were incorporated in the diagnosis. The relationship between the heavy precipitation process and large-scale circulations such as monsoon trough, subtropical high, westerly jet, low level jet and water vapor transport were investigated to further understand the mechanism of this peculiar interaction. It was found that: (1)the mesoscale low developed as a result of cold air advection aloft from northern latitudes and strong convection over the region of humidity convergence on 24 July 2003 over the Indian Rajistan area. (2) On the same day, a low that formed over the Bay of Bengal was transformed into a monsoon depression and moved westward to the mesoscale low which existed over southwest India and the adjoining southeastern parts of Pakistan. (3) Initially, the mesoscale low received moisture supply from both the Bay of Bengal as well as the Arabian Sea, whereas the Bay of Bengal maintained the continuous supply of moisture to the monsoon depression. (4) After the depression crossed central India, the Bay's moisture supply was cut off and the Arabian Sea became the only source of moisture to both the closely located systems. On 27July, both of the systems merged together and the merger resulted in a heavy downpour in the Karachi metropolitan and in its surroundings. (5) With the intensification as well as the southeastward extension of the subtropical high and the shift of the monsoon trough axis from southwest-west to northeast-east,the monsoon depression moved southwestward. In this situation, there existed a very favourable condition for a merger of the two systems in the presence of cross-latitude influence. (6) A number of convective cloud clusters were developed and organized in the mesoscale low. Probably, interactions existed among the multi-scale systems.
英文关键词	mesoscale low tropical depression heavy downpour cross-latitude influence
类型	Article
语种	英语
收录类别	CSCD
WOS研究方向	Meteorology & Atmospheric Sciences
CSCD记录号	CSCD:1998393
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/334887
作者单位	Ghulam RASUL, Meteorological Service of Pakistan.; Qamar-uz-Zaman CHAUDHRY, Meteorological Service of Pakistan.; Zhao Sixiong, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.; Zeng Qingcun, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.; Qi Linlin, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.; Zhang Gaoying, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China.
推荐引用方式 GB/T 7714	Ghulam RASUL,Qamar-uz-Zaman CHAUDHRY,Zhao Sixiong,et al. A Diagnostic Study of Heavy Rainfall in Karachi Due to Merging of a Mesoscale Low and a Diffused Tropical Depression during South Asian Summer Monsoon[J],2005,22(3):375-391.
APA	Ghulam RASUL,Qamar-uz-Zaman CHAUDHRY,Zhao Sixiong,Zeng Qingcun,Qi Linlin,&Zhang Gaoying.(2005).A Diagnostic Study of Heavy Rainfall in Karachi Due to Merging of a Mesoscale Low and a Diffused Tropical Depression during South Asian Summer Monsoon.Advances in Atmospheric Sciences,22(3),375-391.
MLA	Ghulam RASUL,et al."A Diagnostic Study of Heavy Rainfall in Karachi Due to Merging of a Mesoscale Low and a Diffused Tropical Depression during South Asian Summer Monsoon".Advances in Atmospheric Sciences 22.3(2005):375-391.