Four-Decade (1979-2022) Daily Global Snow Cover Fraction Climate Data Record from AVHRR (Version 3.0)

VERSION UPDATE NOTE: 

This version 3.0 composited dataset will not be publicly availble since January 2025. This composited dataset is generated with ESA CCI AVHRR SCF V3.0 products for single sensor, which are available at the website https://catalogue.ceda.ac.uk/uuid/7491427f8c3442ce825ba5472c224322/ and https://catalogue.ceda.ac.uk/uuid/56ff07acabab42888afe2d20b488ec49/.  Anyone interested in AVHRR SCF V3.0 product can test the composite processing according to your needs.

Moreover, our new version dataset (Version 4.0), including the daily compoisted AVHRR SCF product, will be avaiable soon. Given some obvious underestimation errors and missing errors of snow cover pixels in AVHRR 3.0 SCF products, we have done significant improvements for our updaed version AVHRR SCF products (V4.0). 

 [--12/23/2024]

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Data Description

This dataset provides daily composited snow cover fraction (SCF) data, spanning four decades from 1979 to 2022. SCF represents the proportion of snow-covered area observed from space. This dataset is combining the multiple SCF observations derived from three generations of Advanced Very High-Resolution Radiometer (AVHRR) sensors, as part of the ESA CCI+ Snow project (AVHRR/1: TIROS-N, NOAA-6, 8, and 10; AVHRR/2: NOAA-7, 9, 11, 12, and 14; AVHRR/3: NOAA-15, 16, 17, 18, 19, and METOP-A/B/C).

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:

Due to limitations in satellite observations, 110 days of data are missing from the dataset. A list of these dates is provided 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 for the AVHRR SCF products:

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