Measurements > Snow and Ice >
Snow cover, edge and depth

Regular measurements of terrestrial snow cover are important because snow dramatically influences surface albedo, thereby making a significant impact on the global climate, as well as influencing hydrological properties and the regulation of ecosystem biological activity. Snow forms a vital component of the water cycle. In order to make efficient use of meltwater runoff, resource agencies must be able to make early predictions of the amount of water stored in the form of snow. Snow cover information has a range of additional applications such as detecting areas of winterkill in agriculture that result from lack of snow cover to insulate plants from freezing temperatures. Locally, monitoring of snow parameters is important for meteorology and for enabling warnings of when melting is about to occur – which is crucial for hydrological research and for forecasting the risk of flooding.
Detailed MeasurementDescription*InstrumentsTimeline
Snow cover
Fraction of snow in a given area - Physical unit: [ % ] - Accuracy unit: [ % ].55 instruments
Snow detection (mask)Binary product (snow or snow-free) derived from VIS/IR imagery - Accuracy expressed as Hit Rate [ HR ] and False Alarm Rate [ FAR ].1 instrument
Snow Grain SizeGrain size of snow ice particle - Physical unit: [ mm] - Accuracy unit: [ % ].1 instrument
Snow melting status (wet/dry)Binary product (dry or melting/thawing) derived from MW imagery - Accuracy expressed as Hit Rate [ HR ] and False Alarm Rate [ FAR ].2 instruments
Snow surface temperatureTemperature of the surface of the snow mantle - Physical unit: [ K ] - Accuracy unit: [ K ].2 instruments
Snow water equivalent
Total-column water if snow is reduced to liquid. Linked to snow depth through assumptions or observation on density - Physical unit: [ mm ] - Accuracy unit: [ mm ].9 instruments
* Description adapted from WMO.