气候变化领域集成服务门户(CCPortal): An improved vegetation emissivity scheme for land surface modeling and its impact on snow cover simulations

CCPortal

DOI	10.1007/s00382-019-04924-9
	An improved vegetation emissivity scheme for land surface modeling and its impact on snow cover simulations
	Ma X.; Jin J.; Liu J.; Niu G.-Y.
发表日期	2019
ISSN	0930-7575
起始页码	6215
结束页码	6226
卷号	53 期号:2020-09-10
英文摘要	This study developed an improved vegetation emissivity scheme for the Community Land Model (CLM) version 4.5 to more accurately simulate the effects of vegetation emissivity on snow processes in the Northern Hemisphere over winter and spring. The original scheme of vegetation emissivity in CLM produced an unreasonably low vegetation emissivity with a minimum value of around 0.70 in the cold season. Thus, we developed a new vegetation emissivity scheme based on maximum emissivity and leaf and stem area indices of vegetation, which can simulate vegetation emissivity more realistically than the original scheme. Our simulations were driven by the Climatic Research Unit-National Centers for Environmental Prediction (CRU-NCEP) reanalysis data. Results show that CLM with the new scheme produces stronger longwave radiation to the ground surface and generates more solid water drips off vegetation over winter and spring than with the original scheme. Such changes improve snow cover fraction (SCF) simulations for the middle and high latitudes in North America, central Eurasia, and the eastern Tibetan Plateau. About 200 and 350 thousand km2 with the SCF changes show a better SCF simulation with the new scheme over winter and spring, respectively. However, increased errors were found in SCF simulations with the new scheme, and further analysis indicates that such errors may be related to biases in the CLM forcing variables from the CRU-NCEP reanalysis data as compared with those from in situ observations. Moreover, the new emissivity scheme decreases total upward longwave radiation and increases surface net radiation and turbulent fluxes. Overall, the improved vegetation emissivity scheme in this study provides an effective tool to generate better understanding of the effects of vegetation on snow at regional scales and gives strong insight into improved land surface process modeling. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
英文关键词	CLM; Longwave radiation; Snow cover fraction; Solid canopy drips; Vegetation emissivity
语种	英语
scopus关键词	canopy; computer simulation; land surface; longwave radiation; modeling; Northern Hemisphere; snow cover; vegetation
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/145875
作者单位	Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas, Ministry of Education, Northwest A&F University, Yangling, Shaanxi Province 712100, China; College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Department of Watershed Sciences, Utah State University, Logan, UT 84322, United States; Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, United States; Biosphere 2, University of Arizona, Tucson, AZ, United States
推荐引用方式 GB/T 7714	Ma X.,Jin J.,Liu J.,et al. An improved vegetation emissivity scheme for land surface modeling and its impact on snow cover simulations[J],2019,53(2020-09-10).
APA	Ma X.,Jin J.,Liu J.,&Niu G.-Y..(2019).An improved vegetation emissivity scheme for land surface modeling and its impact on snow cover simulations.Climate Dynamics,53(2020-09-10).
MLA	Ma X.,et al."An improved vegetation emissivity scheme for land surface modeling and its impact on snow cover simulations".Climate Dynamics 53.2020-09-10(2019).