气候变化领域集成服务门户(CCPortal): Permafrost variability over the Northern Hemisphere based on the MERRA-2 reanalysis

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DOI	10.5194/tc-13-2087-2019
	Permafrost variability over the Northern Hemisphere based on the MERRA-2 reanalysis
	Tao J.; Koster R.D.; Reichle R.H.; Forman B.A.; Xue Y.; Chen R.H.; Moghaddam M.
发表日期	2019
ISSN	19940416
EISSN	13
起始页码	2087
结束页码	2110
卷号	13 期号:8 页码:2087-2110
英文摘要	This study introduces and evaluates a comprehensive, model-generated dataset of Northern Hemisphere permafrost conditions at 81 resolution. Surface meteorological forcing fields from the Modern-Era Retrospective Analysis for Research and Applications 2 (MERRA-2) reanalysis were used to drive an improved version of the land component of MERRA-2 in middle-to-high northern latitudes from 1980 to 2017. The resulting simulated permafrost distribution across the Northern Hemisphere mostly captures the observed extent of continuous and discontinuous permafrost but misses the ecosystem-protected permafrost zones in western Siberia. Noticeable discrepancies also appear along the southern edge of the permafrost regions where sporadic and isolated permafrost types dominate. The evaluation of the simulated active layer thickness (ALT) against remote sensing retrievals and in situ measurements demonstrates reasonable skill except in Mongolia. The RMSE (bias) of climatological ALT is 1.22m (-0.48) across all sites and 0.33m without the Mongolia sites. In northern Alaska, both ALT retrievals from airborne remote sensing for 2015 and the corresponding simulated ALT exhibit limited skill versus in situ measurements at the model scale. In addition, the simulated ALT has larger spatial variability than the remotely sensed ALT, although it agrees well with the retrievals when considering measurement uncertainty. Controls on the spatial variability of ALT are examined with idealized numerical experiments focusing on northern Alaska; meteorological forcing and soil types are found to have dominant impacts on the spatial variability of ALT, with vegetation also playing a role through its modulation of snow accumulation. A correlation analysis further reveals that accumulated above-freezing air temperature and maximum snow water equivalent explain most of the year-to-year variability of ALT nearly everywhere over the model-simulated permafrost regions. © 2019 Copernicus GmbH. All rights reserved.
语种	英语
WOS研究方向	Physical Geography ; Geology
scopus关键词	active layer; air temperature; airborne sensing; in situ measurement; Northern Hemisphere; permafrost; remote sensing; snow accumulation; spatial variation; Alaska; Mongolia; Siberia; United States
来源期刊	The Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/101356
作者单位	Earth System Science Interdisciplinary Center, University of Maryland, College Park, Maryland, United States; Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, Maryland, United States; Department of Civil and Environmental Engineering, University of Maryland, College Park, Maryland, United States; Department of Electrical Engineering, University of Southern California, Los Angeles, California, United States; Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States; Department of Civil and Environmental Engineering, University of Washington, Seattle, United States; Department of Geography and GeoInformation Science, George Mason University, Fairfax, Virginia, United States
推荐引用方式 GB/T 7714	Tao J.,Koster R.D.,Reichle R.H.,et al. Permafrost variability over the Northern Hemisphere based on the MERRA-2 reanalysis[J],2019,13(8):2087-2110.
APA	Tao J..,Koster R.D..,Reichle R.H..,Forman B.A..,Xue Y..,...&Moghaddam M..(2019).Permafrost variability over the Northern Hemisphere based on the MERRA-2 reanalysis.The Cryosphere,13(8),2087-2110.
MLA	Tao J.,et al."Permafrost variability over the Northern Hemisphere based on the MERRA-2 reanalysis".The Cryosphere 13.8(2019):2087-2110.