Dominant pattern of year-to-year variability of summer precipitation in Nepal during 1987-2015

doi:10.1007/s00704-020-03359-1

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所

	Dominant pattern of year-to-year variability of summer precipitation in Nepal during 1987-2015
	Sharma, Shankar 1; Hamal, Kalpana 2,3; Khadka, Nitesh 3,4,5; Joshi, Bharat Badayar 6
刊名	THEORETICAL AND APPLIED CLIMATOLOGY
	2020-08-31
卷号	142 期号:3-4 页码:1071-1084
关键词	Summer precipitation EOF ENSO IOBM Nepal
ISSN号	0177-798X
DOI	10.1007/s00704-020-03359-1
通讯作者	Hamal, Kalpana(kalpana@mail.iap.ac.cn)
产权排序	4
文献子类	Article
英文摘要	The study of inter-annual variability of summer precipitation is essential for Nepal as it manifests extreme events and thus impacts the socio-economy of the country. This study presents the dominant pattern of summer precipitation (JJAS) and its controlling phenomena during 1987-2015 over Nepal. Here, we used 0.25 degrees x 0.25 degrees APHRODITE and ERA5 reanalysis datasets to compute the empirical orthogonal function (EOF), wavelet, regression, and correlation analysis. The results show two dominant modes of EOF of summer precipitation over Nepal. EOF1 displays a single mode of variability with a 36.3% of variance, whereas EOF2 displays dipole mode of variability with 19.2% of variance, characterized by positive (negative) anomalies in the western (eastern) Nepal. The potential mechanism for the two leading modes is different. PC1 is highly negatively correlated with summer El Nino-Southern Oscillation (ENSO), whereas PC2 is the influence of the Indian Ocean Basin Mode (IOBM), which shows a strong significant negative relationship with the Indian Ocean from preceding spring to concurrent summer. Furthermore, PC1 is associated with strong easterly monsoonal wind flow from the Pacific Ocean and strengthening monsoonal trough over Nepal. However, in PC2, an anomalous low-level vertical circulation was observed between the Indian Ocean (divergence and anticyclonic circulation) and northern India (convergence and cyclonic circulation). The anomalous descending motion and cyclonic circulation strengthen the moisture transport to northern India, which plays a crucial role in increasing precipitation in western Nepal than eastern Nepal. This study provides useful information and underlying mechanism related to the summer monsoon variability of Nepal.
电子版国际标准刊号	1434-4483
WOS关键词	MONSOON RAINFALL ; INTERANNUAL VARIABILITY ; EXTREME PRECIPITATION ; WINTER MONSOON ; DENSE NETWORK ; TEMPERATURE ; MODE ; OSCILLATION ; DATASET ; TRENDS
WOS研究方向	Meteorology & Atmospheric Sciences
语种	英语
出版者	SPRINGER WIEN
WOS记录号	WOS:000564497800001
内容类型	期刊论文
源URL	[http://ir.imde.ac.cn/handle/131551/35617]
专题	中国科学院水利部成都山地灾害与环境研究所
通讯作者	Hamal, Kalpana
作者单位	1.Tribhuvan Univ, Cent Dept Hydrol & Meteorol, Kathmandu 44613, Nepal; 2.Chinese Acad Sci, Int Ctr Climate & Environm Sci, Inst Atmospher Phys, POB 9804, Beijing 100029, Peoples R China; 3.Univ Chinese Acad Sci, Beijing 100049, Peoples R China; 4.Chinese Acad Sci, Inst Mt Hazards & Environm, Chengdu 610041, Peoples R China; 5.Siddhartha Environm Serv, Kathmandu 44600, Nepal; 6.CAS TU, Kathmandu Ctr Res & Educ, Kirtipur, Nepal
推荐引用方式 GB/T 7714	Sharma, Shankar,Hamal, Kalpana,Khadka, Nitesh,et al. Dominant pattern of year-to-year variability of summer precipitation in Nepal during 1987-2015[J]. THEORETICAL AND APPLIED CLIMATOLOGY,2020,142(3-4):1071-1084.
APA	Sharma, Shankar,Hamal, Kalpana,Khadka, Nitesh,&Joshi, Bharat Badayar.(2020).Dominant pattern of year-to-year variability of summer precipitation in Nepal during 1987-2015.THEORETICAL AND APPLIED CLIMATOLOGY,142(3-4),1071-1084.
MLA	Sharma, Shankar,et al."Dominant pattern of year-to-year variability of summer precipitation in Nepal during 1987-2015".THEORETICAL AND APPLIED CLIMATOLOGY 142.3-4(2020):1071-1084.