Knowledge of albedo is of critical importance to land surface monitoring and modelling,
particularly with regard to considerations of climate forecasting and energy exchanges within the biosphere.
When albedo is used in models, it has often been specified as a fixed number for some given land cover type.
However, many years of monitoring from single instruments, such as MODIS, have shown that it can vary significantly
both spatially and temporally. That said, being an angular and spectral integral, it is relatively conservative inter-annually,
other than due to factors such as snow and possibly fire and dramatic land cover change (e.g. flooding, urbanisation).
As particularly high changes in albedo occur due to the presence or absence of snow, modellers tend to consider these two cases separately:
a snow free albedo and one with snow included.
Global albedo data of the land surface is produced from data from 1982-2016 from European and US satellites
daily and monthly with estimated uncertainties for every pixel. There are 3 data products including:
1) AVHRR+GEO Broadband Albedo at 0.5 and 0.05 degrees;
2) Spectral Albedo at 1km; and
3) Sea Ice Spectral Albedo at 1km.