气候变化领域集成服务门户(CCPortal): Multiscale dynamics of transient merging between western disturbances and monsoonal lows: Connections to the July 2023 flood in Himachal Pradesh

CCPortal

DOI	10.1016/j.atmosres.2024.107401
	Multiscale dynamics of transient merging between western disturbances and monsoonal lows: Connections to the July 2023 flood in Himachal Pradesh
	Raghuvanshi, Akash Singh; Agarwal, Ankit
发表日期	2024
ISSN	0169-8095
EISSN	1873-2895
起始页码	304
卷号	304
英文摘要	The Himachal Pradesh region experienced an unprecedented 436% more rainfall than normal from July 7th to 10th, 2023, resulting in devastating landslides, flash floods, and significant socio-economic losses. Using rainfall observations and reanalysis data, this study investigates the dynamics of the extreme precipitation event that caused the disastrous 2023 flood in Himachal Pradesh, India. Prior to the flood, moderate rainfall events saturated the mountainsides, making them more vulnerable to landslides and flash floods. Local features such as rapid convergence, vertical velocity, relative humidity, relative vorticity, and moisture flux accumulation were observed to decrease following the extreme precipitation event, indicating a short -duration cloud burst event. Further, the study reveals a large-scale circulation pattern linking the extratropic and monsoonal low, which is favorable for extreme precipitation in the Himachal Pradesh region. This pattern includes a transient merging of eastward -propagating trough in the mid -upper -level, which extends southward and a monsoon low moving westward across India. The key elements of this transient merging feature consist of a Rossby wave train structure and a blocking high west of the features. The Rossby wave breaking effect occurred downstream of the blocking high two days prior to extreme precipitation event occurrence. This allowed high potential vorticity stratospheric air to intrude the equator and troposphere, causing surface pressure change and enhanced vertical motion, thereby advecting high amount of moisture causing extreme precipitation leading to catastrophic floods. Overall, the findings of this study hold direct implications for early warning systems and disaster preparedness in the face of extreme precipitation -induced flood situations triggered by such transient merging features.
英文关键词	Extreme precipitation events; Atmospheric moisture transport; Rossby wave breaking; Blocking high; Himachal Pradesh flood; Western disturbances
语种	英语
WOS研究方向	Meteorology & Atmospheric Sciences
WOS类目	Meteorology & Atmospheric Sciences
WOS记录号	WOS:001226179900001
来源期刊	ATMOSPHERIC RESEARCH
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/301851
作者单位	Indian Institute of Technology System (IIT System); Indian Institute of Technology (IIT) - Roorkee
推荐引用方式 GB/T 7714	Raghuvanshi, Akash Singh,Agarwal, Ankit. Multiscale dynamics of transient merging between western disturbances and monsoonal lows: Connections to the July 2023 flood in Himachal Pradesh[J],2024,304.
APA	Raghuvanshi, Akash Singh,&Agarwal, Ankit.(2024).Multiscale dynamics of transient merging between western disturbances and monsoonal lows: Connections to the July 2023 flood in Himachal Pradesh.ATMOSPHERIC RESEARCH,304.
MLA	Raghuvanshi, Akash Singh,et al."Multiscale dynamics of transient merging between western disturbances and monsoonal lows: Connections to the July 2023 flood in Himachal Pradesh".ATMOSPHERIC RESEARCH 304(2024).