%0 Dataset
%T A long-term daily 500 m snow cover extent product over China (1981–2000)
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/500dc6a7-7280-4fa0-83fe-3ee9b7ca36a1
%W NCDC
%R 10.12072/ncdc.lzu.db6929.2025
%A SHEN Yanlong 
%A WANG Xiaoyan 
%A ZHU Ruixiang
%A LIANG Shi
%A CHE Tao 
%A HAO Xiaohua 
%K None;None;None
%X Snow is the most widely distributed and significantly changing member of the cryosphere. Its unique high albedo and low thermal conductivity characteristics make it play a key role in regulating surface energy balance, ground atmosphere interactions, and hydrological processes. Due to the limited spatial resolution, temporal resolution, and available time series of early sensors, there is still a lack of long-term series Snow Cover Extend (SCE) products with a spatial resolution of 500m before 2000. To fill this data gap, the study extended the existing SCBOT (Similar Conditional Probability&OTSU) algorithm to the entire China region and made improvements to address some of the shortcomings in the original algorithm. Firstly, the similarity conditional probability (SCP) between images at different scales was calculated using MODIS SCE and AVHRR SCE covering the same time period. Furthermore, based on the 5km AVHRR SCE during the period of 1981-2000, this set of downscaled products was generated through a series of post-processing. The spatial resolution of the product is 500m, the temporal resolution is 1 day, and the data naming format is "YYYYMMDD. tif", such as "19810626. tif", which contains six pixel values (0=land, 1=SCP identified snow, 2=spatiotemporal cube (STCPI) interpolated snow, 3=snow depth interpolated snow, 4=water, 255=fill value). This product effectively fills the data gap during this period and is of great significance for long-term climate change research, water resource management, and ecological protection.