气候变化领域集成服务门户(CCPortal): Dynamics of Freezing/Thawing Indices and Frozen Ground from 1961 to 2010 on the Qinghai-Tibet Plateau

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DOI	10.3390/rs15143478
	Dynamics of Freezing/Thawing Indices and Frozen Ground from 1961 to 2010 on the Qinghai-Tibet Plateau
	Fang, Xuewei; Wang, Anqi; Lyu, Shihua; Fraedrich, Klaus
发表日期	2023
EISSN	2072-4292
卷号	15 期号:14
英文摘要	Freezing/thawing indices are important indicators of the dynamics of frozen ground on the Qinghai-Tibet Plateau (QTP), especially in areas with limited observations. Based on the numerical outputs of Community Land Surface Model version 4.5 (CLM4.5) from 1961 to 2010, this study compared the spatial and temporal variations between air freezing/thawing indices (2 m above the ground) and ground surface freezing/thawing indices in permafrost and seasonally frozen ground (SFG) across the QTP after presenting changes in frozen ground distribution in each decade in the context of warming and wetting. The results indicate that an area of 0.60 x 10(6) km(2) of permafrost in the QTP degraded to SFG in the 1960s-2000s, and the primary shrinkage period occurred in the 2000s. The air freezing index (AFI) and ground freezing index (GFI) decreased dramatically at rates of 71.00 & DEG;C & BULL;d/decade and 34.33 & DEG;C & BULL;d/decade from 1961 to 2010, respectively. In contrast, the air thawing index (ATI) and ground thawing index (GTI) increased strikingly, with values of 48.13 & DEG;C & BULL;d/decade and 40.37 & DEG;C & BULL;d/decade in the past five decades, respectively. Permafrost showed more pronounced changes in freezing/thawing indices since the 1990s compared to SFG. The changes in thermal regimes in frozen ground showed close relations to air warming until the late 1990s, especially in 1998, when the QTP underwent the most progressive warming. However, a sharp increase in the annual precipitation from 1998 began to play a more controlling role in thermal degradation in frozen ground than the air warming in the 2000s. Meanwhile, the following vegetation expansion hiatus further promotes the thermal instability of frozen ground in this highly wet period.
关键词	freezing thawing indices permafrost dynamics Community Land Surface Model Qinghai-Tibet Plateau
英文关键词	NEAR-SURFACE AIR; PERMAFROST DEGRADATION; NORTHERN-HEMISPHERE; VEGETATION DYNAMICS; MODEL SIMULATIONS; CLIMATE-CHANGE; ACTIVE-LAYER; RIVER-BASIN; THAW; TEMPERATURE
WOS研究方向	Environmental Sciences ; Geosciences, Multidisciplinary ; Remote Sensing ; Imaging Science & Photographic Technology
WOS记录号	WOS:001036683500001
来源期刊	REMOTE SENSING
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/282857
作者单位	Chengdu University of Information Technology; Max Planck Society; Nanjing University of Information Science & Technology
推荐引用方式 GB/T 7714	Fang, Xuewei,Wang, Anqi,Lyu, Shihua,et al. Dynamics of Freezing/Thawing Indices and Frozen Ground from 1961 to 2010 on the Qinghai-Tibet Plateau[J],2023,15(14).
APA	Fang, Xuewei,Wang, Anqi,Lyu, Shihua,&Fraedrich, Klaus.(2023).Dynamics of Freezing/Thawing Indices and Frozen Ground from 1961 to 2010 on the Qinghai-Tibet Plateau.REMOTE SENSING,15(14).
MLA	Fang, Xuewei,et al."Dynamics of Freezing/Thawing Indices and Frozen Ground from 1961 to 2010 on the Qinghai-Tibet Plateau".REMOTE SENSING 15.14(2023).