气候变化领域集成服务门户(CCPortal): Near surface air temperature lapse rates over complex terrain: a WRF based analysis of controlling factors and processes for the central Himalayas

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DOI	10.1007/s00382-019-05003-9
	Near surface air temperature lapse rates over complex terrain: a WRF based analysis of controlling factors and processes for the central Himalayas
	Karki R.; Hasson S.; Schickhoff U.; Scholten T.; Böhner J.; Gerlitz L.
发表日期	2020
ISSN	0930-7575
起始页码	329
结束页码	349
卷号	54 期号:2020-01-02
英文摘要	Various environmental processes are strongly controlled by spatio-temporal variations of surface air temperature (hereafter temperature) in complex terrain. However, the usually scarce network of observations in high mountain regions does not allow for an investigation of the relevant micro-meteorological processes that result in complex temperature fields. Climate impact studies often utilize a constant lapse rate of temperature (LRT hereafter) in order to generate spatially distributed temperature data, although it is well acknowledged that LRTs feature a pronounced variability at spatial, seasonal, and diurnal scales. In this study, the Weather Research and Forecasting (WRF) model is used to understand the factors and processes influencing temperature and LRT in the Khumbu and Rolwaling regions of the central Himalayas. A high resolution simulation is performed for one complete year (June 2014–May 2015) in order to capture the entire seasonal cycle. To test the model response to land cover and terrain characteristics, additional simulations with adjusted surface conditions are conducted. Our results demonstrate the capability of WRF to reproduce the processes controlling LRT, although an LRT bias is detected during non-monsoon seasons. The simulated temperature fields feature two LRT minima (i.e. low temperature decrease with elevation) during Nov–Dec and monsoon season, and two LRT maxima (strong temperature decrease with elevation) during the early post-monsoon and pre-monsoon seasons. A steeper LRT (i.e. a rapid decrease of temperature with elevation) is found at high elevations (> 4500 m) while shallower LRT values (i.e. a slower decrease or even increase of temperature with elevation) are apparent at lower elevations. During the pre-monsoon season, high net insolation rates and a reduced latent heat loss from snow free surfaces cause strong sensible heating at low elevations, while the presence of snow at high elevations leads to reduced sensible heating. This strong contrast results in steeper LRT values. Early post-monsoon shows similar characteristics but with a reduced magnitude. The shallow LRT during monsoon season is shown to be caused by the large-scale moisture supply and the associated latent heat release at the Himalayan slopes. This effect is further intensified due to strong up-valley winds which contribute to a well-mixed troposphere. Temperature inversions associated with cold air pooling cause shallow LRT values in lower river valleys during Nov–Dec. The results suggest that the identified processes should be considered for downscaling applications, particularly if distributed temperature fields are required for climate impact investigations. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	Central Himalayas; Latent heat of condensation; Sensible heat; Temperature lapse rate; Wind; WRF
语种	英语
scopus关键词	air temperature; climate modeling; complex terrain; condensation; downscaling; latent heat flux; mountain region; research work; sensible heat flux; spatiotemporal analysis; surface temperature; weather forecasting; wind field; Himalayas
来源期刊	Climate Dynamics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/145767
作者单位	Center for Earth System Research and Sustainability, Institute of Geography, University of Hamburg, Bundesstraße 55, Hamburg, 20146, Germany; Department of Hydrology and Meteorology, Government of Nepal, 406 Naxal, Kathmandu, Nepal; Department of Space Sciences, Institute of Space Technology, Islamabad, 44000, Pakistan; Soil Science and Geomorphology, Department of Geosciences, University of Tübingen, Rümelinstrasse 19-23, Tübingen, 72070, Germany; Section Hydrology, GFZ German Research Centre for Geosciences, Telegrafenberg, Potsdam, 14473, Germany
推荐引用方式 GB/T 7714	Karki R.,Hasson S.,Schickhoff U.,et al. Near surface air temperature lapse rates over complex terrain: a WRF based analysis of controlling factors and processes for the central Himalayas[J],2020,54(2020-01-02).
APA	Karki R.,Hasson S.,Schickhoff U.,Scholten T.,Böhner J.,&Gerlitz L..(2020).Near surface air temperature lapse rates over complex terrain: a WRF based analysis of controlling factors and processes for the central Himalayas.Climate Dynamics,54(2020-01-02).
MLA	Karki R.,et al."Near surface air temperature lapse rates over complex terrain: a WRF based analysis of controlling factors and processes for the central Himalayas".Climate Dynamics 54.2020-01-02(2020).