A 45-year (1979-2023) Global Daily Snow Cover Fraction Climate Data Record from multiple AVHRR satellites (AVHRR10C1.V4)

VERSION UPDATE NOTE: ----Jan. 15, 2026 Update------ Now the algorithm description is available. You can refer to the publication (Xiao et al. 2025 RSE). If you use this data, please cite this paper. Xiao, X., Naegeli, K., Premier, V., Li, S., Neuhaus, C., Wiesmann, A. & Wunderle, S. (2026). Introduction to a 45-year ( 1979 – 2023 ) global daily snow cover fraction product from multiple AVHRR satellites with accuracy assessment. Remote Sensing of Environment, 334 (March 2026), 115235. https://doi.org/10.1016/j.rse.2026.115235 ------------------------------------------------------------------------------------------------------------------------------------------------- Data Description AVHRR10C1.V4 dataset provides gobla daily snow cover fraction (SCF) data at a 0.05° grid cell, spanning four decades (Jan. 1979 to Dec. 2023). SCF represents the proportion of snow-covered area observed from space. This dataset consolidates multiple AVHRR SCF observations derived from three generations of Advanced Very High-Resolution Radiometer (AVHRR) sensors, as part of the ESA Snow CCI+ Phase-2 project (AVHRR/1: TIROS-N, NOAA-6, 8, and 10; AVHRR/2: NOAA-7, 9, 11, 12, and 14; AVHRR/3: 16, 17, 18, 19, and METOP-A/B/C). The algorithm description will be updated lately [The latest update date --- August 6th, 2025]. Date types The dataset includes two types of SCF: Snow Cover Fraction Viewable (SCFV): Represents the area of snow visible over land surface from space, while snow area in forested area refers to snow visible on top of forest canopies. Snow Cover Fraction on Ground (SCFG): Represents snow on the ground, with corrections applied in forested areas to account for the obstruction caused by forest canopy. Both SCFV and SCFG are provided in percentage (%) per grid, at a spatial resolution of 0.05° (approximately 5 km). The data covers all land areas globally, excluding Antarctica and Greenland ice sheets. Important Notes: The dataset contains gaps for 110 days due to limited availability of AVHRR sensor observations. The missing dates are listed in the accompanying file Dates List of Missing Data.xlsx." The dataset is organized by year, with each day's data stored in a separate GeoTIFF (*.tif) file. Code values of AVHRR10C1.V4 SCF data: Codes Description 0 - 100 Snow cover fraction (SCF) [%]; 0: snow freee; 100: fully snow covered 205 Cloud 206 Polar night 210 Water 215 Glacier, Icecaps, Icesheets 254 ERROR: No satellite acuqisition