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. |
|
| Domain: | Terrestrial | |
| Subdomain: | Cryosphere | |
| Scientific Area: | Snow and Ice | |
| ECV Steward: | Colleen Mortimer | |
| Products: | Area covered by snow; Snow depth; Snow water equivalent | |
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 | ||||||
| (*) | Unit | Values | Unit | Values | Unit | Values | |||
| Horizontal Resolution | G | m | 50 | km | 0.5 | km | 0.5 | ||
| B | 500 | 5 | 5 | ||||||
| T | 1000 | 25 | 25 | ||||||
| Vertical Resolution | G | - | - | - | |||||
| B | - | - | - | ||||||
| T | - | - | - | ||||||
| Temporal Resolution | G | h | 6 | d | 6 | h | 6 | ||
| B | 24 | 24 | 24 | ||||||
| T | 48 | 48 | 48 | ||||||
| Timeliness | G | h | 3 | h | 1 | h | 3 | ||
| B | 24 | 6 | 24 | ||||||
| T | 240 | 24 | 240 | ||||||
| Required Measurement Uncertainty (2-sigma) | G | % | 5 | mm | 10 | mm | 1 | ||
| B | 15 | 25 | 5 | ||||||
| T | 20 | 50 | 10 | ||||||
| Stability | G | % | 1 | cm | 1 | mm | 5 | ||
| B | 5 | 2 | 8 | ||||||
| T | 10 | 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 GCOS Secretariat.
- Satellite ECV Inventory by the CEOS/CGMS Working Group on Climate (WGClimate)
