气候变化领域集成服务门户(CCPortal): A Spatiotemporal Enhanced SMAP Freeze/Thaw Product (1980-2020) over China and Its Preliminary Analyses

CCPortal

DOI	10.3390/rs16060950
	A Spatiotemporal Enhanced SMAP Freeze/Thaw Product (1980-2020) over China and Its Preliminary Analyses
	Cui, Hongjing; Chai, Linna; Li, Heng; Zhao, Shaojie; Li, Xiaoyan; Liu, Shaomin
发表日期	2024
EISSN	2072-4292
起始页码	16
结束页码	6
卷号	16 期号:6
英文摘要	The soil freeze/thaw (FT) state has emerged as a critical role in the ecosystem, hydrological, and biogeochemical processes, but obtaining representative soil FT state datasets with a long time sequence, fine spatial resolution, and high accuracy remains challenging. Therefore, we propose a decision-level spatiotemporal data fusion algorithm based on Convolutional Long Short-Term Memory networks (ConvLSTM) to expand the SMAP-enhanced L3 landscape freeze/thaw product (SMAP_E_FT) temporally. In the algorithm, the Freeze/Thaw Earth System Data Record product (ESDR_FT) is sucked in the ConvLSTM and fused with SMAP_E_FT at the decision level. Eight predictor datasets, i.e., soil temperature, snow depth, soil moisture, precipitation, terrain complexity index, area of open water data, latitude and longitude, are used to train the ConvLSTM. Direct validation using six dense observation networks located in the Genhe, Maqu, Naqu, Pali, Saihanba, and Shandian river shows that the fusion product (ConvLSTM_FT) effectively absorbs the high accuracy characteristics of ESDR_FT and expands SMAP_E_FT with an overall average improvement of 2.44% relative to SMAP_E_FT, especially in frozen seasons (averagely improved by 7.03%). The result from indirect validation based on categorical triple collocation also shows that ConvLSTM_FT performs stable regardless of land cover types, climate types, and terrain complexity. The findings, drawn from preliminary analyses on ConvLSTM_FT from 1980 to 2020 over China, suggest that with global warming, most parts of China suffer from different degrees of shortening of the frozen period. Moreover, in the Qinghai-Tibet region, the higher the permafrost thermal stability, the faster the degradation rate.
英文关键词	soil freeze/thaw product; temporal expanding; SMAP; long time series; spatiotemporal fusion; ConvLSTM
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Geology ; Remote Sensing ; Imaging Science & Photographic Technology
WOS类目	Environmental Sciences ; Geosciences, Multidisciplinary ; Remote Sensing ; Imaging Science & Photographic Technology
WOS记录号	WOS:001192559000001
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/309960
作者单位	Beijing Normal University
推荐引用方式 GB/T 7714	Cui, Hongjing,Chai, Linna,Li, Heng,et al. A Spatiotemporal Enhanced SMAP Freeze/Thaw Product (1980-2020) over China and Its Preliminary Analyses[J],2024,16(6).
APA	Cui, Hongjing,Chai, Linna,Li, Heng,Zhao, Shaojie,Li, Xiaoyan,&Liu, Shaomin.(2024).A Spatiotemporal Enhanced SMAP Freeze/Thaw Product (1980-2020) over China and Its Preliminary Analyses.REMOTE SENSING,16(6).
MLA	Cui, Hongjing,et al."A Spatiotemporal Enhanced SMAP Freeze/Thaw Product (1980-2020) over China and Its Preliminary Analyses".REMOTE SENSING 16.6(2024).