Long-term Monthly ESA CCI–DLR Average Snow Cover Probability, 2000–2025 at 500 m resolution

This dataset contains long-term monthly products for snow cover probability, derived from DLR Global SnowPack and ESA CCI MODIS Terra snow cover data. The ensemble product combines long-term monthly statistics from both input products. For areas north of 30°N, the DLR and ESA CCI products were merged using equal weights. For areas south of 30°N, the DLR product was given a 10 times smaller weight.

Dataset contents

The archive includes long-term monthly ensemble layers for each calendar month from January to December. The available statistics are:

• p05

• p50

• p95

All products are stored as Byte GeoTIFFs:

• 0–100 = snow cover probability in percent

• 255 = NoData

The products are provided at 500 m spatial resolution and follow the source grid used in the processing workflow.

Data sources

The DLR Global SnowPack data were downloaded from: https://download.geoservice.dlr.de/GSP/files/daily/

The ESA CCI snow cover data were downloaded from: https://data.ceda.ac.uk/neodc/esacci/snow/data/scfg/MODIS/v4.0

The ESA CCI product is a daily MODIS Terra snow cover product at 1 km spatial resolution. It was resampled to 500 m to match the DLR Global SnowPack product.

Processing summary

First, monthly snow cover products were prepared separately for DLR Global SnowPack and ESA CCI.

For the DLR product, snow-covered pixels were selected using the original source encoding:

• snow-covered pixels: values >= 64

• valid snow-free land: bit 32

NoData, invalid, water and non-land pixels were excluded from the monthly denominator.

For the ESA CCI product, monthly snow cover statistics were calculated from daily snow cover probability values. A 10% snow threshold was used to identify valid snowy days, following the same general approach used for the DLR SnowPack processing.

For both products, long-term monthly statistics were calculated for each calendar month:

• p05 (0.05% quantile),

• p50 (median),

• p95 (0.95% quantile),

The two products were then merged into an average ensemble product.

Ensemble weighting

The ensemble product uses different weights by latitude:

• north of 30°N: equal weights for DLR and ESA CCI

• south of 30°N: the DLR product receives a 10 times smaller weight

This weighting was used to reduce the influence of DLR Global SnowPack in lower-latitude areas.

Data encoding

All ensemble products are stored as Byte GeoTIFFs:

• 0–100 = snow cover probability in percent

• 255 = NoData

Spatial and temporal coverage

Spatial coverage: global land areas covered by the input products
Spatial resolution: 500 m
Coordinate reference system: EPSG:4326
Temporal coverage: 2000–2025
Temporal summary: long-term monthly statistics for January to December

File naming

The products follow the OGH-style naming convention.

Example:

snowcover_cci.dlr.average.jan_p50_500m_s_20000101_20251231_go_epsg.4326_v20260605.tif

where:

• snowcover = variable name

• cci.dlr.average.jan = ESA CCI and DLR average product for January

• p50 = statistic

• 500m = spatial support

• s = surface

• 20000101_20251231 = temporal range

• go = global extent

• epsg.4326 = coordinate reference system

• v20260605 = processing version

Citation note

Users should cite this derived dataset together with the original DLR Global SnowPack and ESA CCI snow cover products.