气候变化领域集成服务门户(CCPortal): Inter-Annual Variability of Winter Precipitation Over Nepal Coupled With Ocean-Atmospheric Patterns During 1987-2015

CCPortal

DOI	10.3389/feart.2020.00161
	Inter-Annual Variability of Winter Precipitation Over Nepal Coupled With Ocean-Atmospheric Patterns During 1987-2015
	Hamal, Kalpana; Sharma, Shankar; Baniya, Binod; Khadka, Nitesh; Zhou, Xu
通讯作者	Sharma, S (通讯作者)
发表日期	2020
EISSN	2296-6463
卷号	8
英文摘要	Nepal is a mountainous country located on the southern slope of the central Himalayas, where the winter season contributes similar to 3% of the total annual rainfall. This study sought to investigate the inter-annual variability and associated ocean-atmospheric pattern with winter precipitation during 1987-2015. A high-resolution APHRODITE and ERA5 reanalysis datasets are used to study the Empirical Orthogonal Function (EOF), Wavelet, Composites, and Correlation analysis, respectively. The results show that the leading EOF mode captures 53.2% of the total variance, exhibiting a single mode of variability. Wavelet analysis determined 2 to 2.6 years of the significant power spectrum. The time-series of winter precipitation anomalies revealed the years 1996, 1998, 2000, 2005, 2007, and 2008 as precipitation deficit years which is supported by negative precipitation anomalies with positive outgoing longwave radiation (OLR) and vertical velocity. These phenomena are converse for wet events during the years 1988, 1995, 1997, 2002, 2012, and 2014. Furthermore, the wet (dry) years exhibit moisture convergence (divergence) with strong southwesterly (northwesterly) wind anomalies. In the wave train of westerly flow, the cyclonic and anticyclonic circulation in northern India affects the moisture transport in wet and dry years, respectively. In excess precipitation years, Surface Air Temperature (SAT) over entire northern India and adjoining Nepal and Tibetan Plateau (TP) regions have a colder temperature than in deficit precipitation years. The correlation suggests the instance of Indian Ocean Basin Mode (IOBM) and NINO3.4 impacts on the inter-annual variability of the winter precipitation. Moreover, the warming and cooling over the Indo-Pacific regions affect the Walker and Hadley circulation bringing above and below-normal precipitation, respectively, over Nepal. The observed changes in the dry and wet years during winter are useful for disaster preparedness and the planning and monitoring of water resources and agriculture.
关键词	MONSOON RAINFALL AIR-TEMPERATURE SOUTHWEST ASIA DENSE NETWORK SURFACE INDIA DATASET IMPACT
英文关键词	winter precipitation variability; dry events; wet events; westerlies; Nepal
语种	英语
WOS研究方向	Geology
WOS类目	Geosciences, Multidisciplinary
WOS记录号	WOS:000539708100001
来源期刊	FRONTIERS IN EARTH SCIENCE
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259947
推荐引用方式 GB/T 7714	Hamal, Kalpana,Sharma, Shankar,Baniya, Binod,et al. Inter-Annual Variability of Winter Precipitation Over Nepal Coupled With Ocean-Atmospheric Patterns During 1987-2015[J]. 中国科学院青藏高原研究所,2020,8.
APA	Hamal, Kalpana,Sharma, Shankar,Baniya, Binod,Khadka, Nitesh,&Zhou, Xu.(2020).Inter-Annual Variability of Winter Precipitation Over Nepal Coupled With Ocean-Atmospheric Patterns During 1987-2015.FRONTIERS IN EARTH SCIENCE,8.
MLA	Hamal, Kalpana,et al."Inter-Annual Variability of Winter Precipitation Over Nepal Coupled With Ocean-Atmospheric Patterns During 1987-2015".FRONTIERS IN EARTH SCIENCE 8(2020).