Albedo
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The land surface albedo is the ratio of the radiant flux reflected from Earth’s surface to the incident flux. It is a key forcing parameter controlling the partitioning of radiative energy between the atmospheric and surface. In the case of vegetation, a reference surface is typically defined at or near the top of the canopy and must be specified explicitly. Surface albedo depends on natural variations, highly variable in space and time as a result of terrestrial properties changes, and with illumination conditions and human activities and is a sensitive indicator of environmental vulnerability. |
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| Domain: | Terrestrial | |
| Subdomain: | Biology | |
| Scientific Area: | Energy | |
| ECV Steward: | Nadine Gobron | |
| Products: | Spectral and Broadband (visible, near infrared and shortwave) DHR & BHR with Associated Spectral Bidirectional Reflectance Distribution Function (BRDF) parameters (required to derive albedo from reflectance) | |
Trend of Albedo
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Figure: Trend of Albedo in March from 2000 to 2018. Significant slopes in [% year -1] MCD43C3 (WSA-Shortwave).
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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 Albedo.
| Products | Spectral and Broadband (visible, near infrared and shortwave) DHR & BHR with Associated Spectral Bidirectional Reflectance Distribution Function (BRDF) parameters (required to derive albedo from reflectance) | ||
| (*) | Unit | Values | |
| Horizontal Resolution | G | m | 10 |
| B | |||
| T | 250 | ||
| Vertical Resolution | G | - | |
| B | - | ||
| T | - | ||
| Temporal Resolution | G | day | 1 |
| B | |||
| T | 10 | ||
| Timeliness | G | day | 1 |
| B | |||
| T | 5 | ||
| Required Measurement Uncertainty (2-sigma) | G | y | 3% for values ≥0.05; 0.0015 (absolute value) for smaller values |
| B | |||
| T | 5% for values ≥0.05; 0.0025 for smaller values |
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| Stability | G | %/decade | < 1 % |
| B | |||
| T | < 1.5 % | ||
(*) 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.
- MODIS Collection 6 surface albedo
https://modis.gsfc.nasa.gov/data/dataprod/mod43.php
- Copernicus Climate Change Service (C3S) data store
https://cds.climate.copernicus.eu/#!/home
- Satellite ECV Inventory by the CEOS/CGMS Working Group on Climate (WGClimate)
