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Solargis provides 2 solutions for surface albedo data:
Both solutions use MODIS albedo data products as the primary data source, although additional processing and error corrections have been carried out by Solargis.
The Moderate Resolution Imaging Spectroradiometer (MODIS) is an instrument aboard the Terra and Aqua satellites. The orbits of the satellites around the Earth are so that Terra crosses over the equator from north to south in the morning. Aqua moves in the opposite direction, from south to north in the afternoon. The instruments cover the globe every 1 to 2 days.
Technical characteristics of Solargis albedo data products:
Characteristic |
Long-term monthly averages |
Time series |
Data sources |
MODIS (main): MCD43GF MODIS (snow albedo): MCD43C3, MOD10CM, MYD10CM ERA-5 (gap-filling) NSIDC (sea ice) Solargis (1km land-sea mask) |
MODIS: MCD43A3 Diffuse fraction (D2G) from Solargis irradiance database |
Spatial resolution |
1 km x 1 km |
0.5 km x 0.5 km |
Temporal structure |
Monthly-means (12) + annual-means (1) Monthly-means from 8-days values (each day value is a weighted average based on a temporal window of 16 days) |
Daily time series Each day value is a weighted average based on a temporal window of 16 days centred in day 9 |
Time coverage |
2006 to 2015, 10 years |
Feb 2000 to present, 18+ years |
Gaps in data |
No |
Yes |
Access |
Solargis Prospect Pro |
Upon request. A technical report is issued along with the data file. |
The database of long-term average albedo values is of a set of 12 (monthly averages) +1 (annual average) maps that can be accessed via the Solargis Prospect tool. It provides gap-free albedo data at high resolution and with global coverage.
The gap-filled snow-free MODIS product MCD43GF has been used as the primary data source. However, since this MODIS product does not include albedo values for ephemeral snow, information from several MODIS products and ERA5 data has been combined to prepare a gap-free high-resolution dataset for all kind of land surfaces (including ephemeral snow). Finally, additional information was used to add the albedo of ocean ice, and to correct imperfections and errors related to imprecisions of the MODIS land-sea mask.
For Solargis time series of albedo, data sources that have a long historic record and reasonably high temporal resolution (at least daily values) are used. These include MODIS products MCD43A1 and MCD43A3. However, these products present missing data (data gaps), mainly due to persistent cloudiness.
The choice of data solution (monthly averages or time series) that should be used depends on project requirements. Typically, the use of the monthly average database is recommended in the pre-feasibility stage and use of time series is recommended in the due diligence phase.
Some examples of situations when the use of time series is more appropriate include: