气候变化领域集成服务门户(CCPortal): Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River (SAYR)

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DOI	10.1007/s11434-014-0189-6
	Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River (SAYR)
	Luo, Dongliang; Jin, Huijun; Lu, Lanzhi; Wu, Qingbai
发表日期	2014
ISSN	1001-6538
EISSN	1861-9541
起始页码	3034
结束页码	3045
卷号	59 期号:24
英文摘要	Based on the analysis of data on temperatures and moisture of soils in the active layer at four different permafrost sites in the source areas of the Yellow River (SAYR) in 2010-2012, the freeze-thaw processes of soils in the active layer were compared and contrasted for understanding the spatiotemporal variations. At the four studied sites, the thickness and mean annual temperature of permafrost are different. The temperatures at the top of permafrost (TTOP), i.e., the maximum depth(s) of seasonal frost and/or thaw penetration, are -1.9 A degrees C at the Chalaping site (CLP), -0.9 A degrees C at the site on the southern bank of the Zhaling Lake (ZLH), -0.4 A degrees C at the Maduo Town site (MDX), and 1.1 A degrees C at the site on the northern bank of the Eling Lake (ELH). Differences in the mean annual ground temperature of permafrost and TTOPs may be responsible for the differentiations in the freeze-thaw processes of soils in the active layer. With rising TTOPs, the ground thawing started earlier: CLP in early June, ZLH in late May, MDX in early May, and ELH in mid-April, while the freezing began later: CLP in early October, ZLH in early to mid-October, MDX in mid-October, and ELH in the mid- to late October. With increasing TTOPs, the freeze-up periods for permafrost sites were shortened: 202 days at CLP, 130 days at ZLH, 100 days at MDX, and the period of complete thaw was 89 days at ELH. At the CLP and ZLH sites, the two-directional ground freezing (downwards from ground surfaces and upwards from the permafrost table) and thawing finished in the same year, but the ground freezing at the MDX continued to the end of the next January, with very slow freezing rates in the end. At the ELH site, ground freezing kept on until early May when thawing began on the surface, and upward and downward thawing became increasingly stable in late June to early July. At each site, with rising TTOPs, the downward freezing accelerated in comparison with the upward freezing, and with an increasing proportion of downward frozen depth, and with the larger ratios of freezing to thawing duration. In summary, the patterns of thawing and freezing processes in the active layer in the SAYR differ from those in other parts of the Qinghai-Tibet Plateau to a noticeable extent.
英文关键词	Warm permafrost; Active layer; Freezing processes; Thawing processes; Freeze-up period; Zero-curtain
语种	英语
WOS研究方向	Science & Technology - Other Topics
WOS类目	Multidisciplinary Sciences
WOS关键词	THERMAL REGIME ; VEGETATION COVER ; COASTAL-PLAIN ; PERMAFROST ; THICKNESS ; DEPTH ; SOIL
WOS记录号	WOS:000339104800013
来源期刊	CHINESE SCIENCE BULLETIN
来源机构	中国科学院西北生态环境资源研究院
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/240212
作者单位	[Luo, Dongliang; Jin, Huijun; Lu, Lanzhi; Wu, Qingbai] Chinese Acad Sci, State Key Lab Frozen Soils Engn, Cold & Arid Reg Environm & Engn Res Inst, Lanzhou 730000, Peoples R China
推荐引用方式 GB/T 7714	Luo, Dongliang,Jin, Huijun,Lu, Lanzhi,et al. Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River (SAYR)[J]. 中国科学院西北生态环境资源研究院,2014,59(24).
APA	Luo, Dongliang,Jin, Huijun,Lu, Lanzhi,&Wu, Qingbai.(2014).Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River (SAYR).CHINESE SCIENCE BULLETIN,59(24).
MLA	Luo, Dongliang,et al."Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River (SAYR)".CHINESE SCIENCE BULLETIN 59.24(2014).