Snow

Snow refers to forms of ice crystals that precipitate from the atmosphere (usually from clouds) and undergo changes on the Earth's surface. Snow cover on the ground plays a significant role in the climate system due to its high albedo, heat insulation and contribution to soil moisture and runoff, thus an important variable in monitoring climate change.

Change in Snow Cover Extent

Figure: 12-month running anomalies of monthly snow extent are plotted on the 7th month using values from November 1966 to December 2018.

Source : Global Snow Lab,, https://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=0&ui_region…


ECV Products and Requirements

These products and requirements reflect the Implementation Plan 2022 (GCOS-244).

The requirements are found in the complete 2022 ECVs Requirements document as well: ECV Snow.

Products Area Covered by Snow  Snow Depth  Snow-Water Equivalent
 (*)UnitValues UnitValues UnitValues
Horizontal ResolutionGm50 km0.5 km0.5
B500 5 5
T1000 25 25
Vertical ResolutionG -  -  -
B- - -
T- - -
Temporal ResolutionGh6 d6 h6
B24 24 24
T48 48 48
TimelinessGh3 h1 h3
B24 6 24
T240 24 240
Required Measurement Uncertainty (2-sigma)G%5 mm10 mm1
B15 25 5
T20 50 10
StabilityG%1 cm1 mm5
B5 2 8
T10 5 10
 

(*) Goal (G): an ideal requirement above which further improvements are not necessary. Breakthrough (B): an intermediate level between threshold and goal which, if achieved, would result in a significant improvement for the targeted application. The breakthrough value may also indicate the level at which specified uses within climate monitoring become possible. It may be appropriate to have different breakthrough values for different uses. Threshold (T): the minimum requirement to be met to ensure that data are useful.

Data sources

This list provides sources for openly accessible data sets with worldwide coverage for which metadata is available. It is curated by the respective GCOS ECV Steward(s). The list does not claim to be complete. Anyone with a suitable dataset who wishes it to be added to this list should contact the abombelliatwmo [dot] int (GCOS Secretariat).

Snow
Домен:
Land
Subdomain:
Cryosphere
Scientific Area:
Snow and Ice
ECV Steward:
Colleen Mortimer
Products:
Area covered by snow; Snow depth; Snow water equivalent