气候变化领域集成服务门户(CCPortal): The ERA5-Land soil temperature bias in permafrost regions

CCPortal

DOI	10.5194/tc-14-2581-2020
	The ERA5-Land soil temperature bias in permafrost regions
	Cao B.; Gruber S.; Zheng D.; Li X.
发表日期	2020
ISSN	19940416
起始页码	2581
结束页码	2595
卷号	14 期号:8
英文摘要	ERA5-Land (ERA5L) is a reanalysis product derived by running the land component of ERA5 at increased resolution. This study evaluates ERA5L soil temperature in permafrost regions based on observations and published permafrost products. We find that ERA5L overestimates soil temperature in northern Canada and Alaska but underestimates it in mid-low latitudes, leading to an average bias of -0.08 ĝC. The warm bias of ERA5L soil is stronger in winter than in other seasons. As calculated from its soil temperature, ERA5L overestimates active-layer thickness and underestimates near-surface (<1.89 m) permafrost area. This is thought to be due in part to the shallow soil column and coarse vertical discretization of the land surface model and to warmer simulated soil. The soil temperature bias in permafrost regions correlates well with the bias in air temperature and with maximum snow height. A review of the ERA5L snow parameterization and a simulation example both point to a low bias in ERA5L snow density as a possible cause for the warm bias in soil temperature. The apparent disagreement of station-based and areal evaluation techniques highlights challenges in our ability to test permafrost simulation models. While global reanalyses are important drivers for permafrost simulation, we conclude that ERA5L soil data are not well suited for informing permafrost research and decision making directly. To address this, future soil temperature products in reanalyses will require permafrost-specific alterations to their land surface models. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License.
英文关键词	air temperature; decision making; land surface; parameterization; permafrost; sampling bias; shallow soil; soil column; soil temperature; Alaska; Canada; United States
语种	英语
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202041
作者单位	National Tibetan Plateau Data Center, Key Laboratory of Tibetan Environmental Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China; Department of Geography and Environmental Studies, Carleton University, Ottawa, Canada; Cas Center for Excellence in Tibetan Plateau Earth Sciences, Chinese Academy of Sciences, Beijing, China
推荐引用方式 GB/T 7714	Cao B.,Gruber S.,Zheng D.,et al. The ERA5-Land soil temperature bias in permafrost regions[J],2020,14(8).
APA	Cao B.,Gruber S.,Zheng D.,&Li X..(2020).The ERA5-Land soil temperature bias in permafrost regions.Cryosphere,14(8).
MLA	Cao B.,et al."The ERA5-Land soil temperature bias in permafrost regions".Cryosphere 14.8(2020).