This data set comprises the (8-) daily gross primary production (GPP) and the annual net primary production (NPP) together with various quality and confidence flags derived from MODIS collection 6 radiance and reflectance observations.
Derivation of the NPP is rooted on i) plant NPP is directly related to the absorbed solar energy; ii) NDVI and EVI as observed, e.g. by MODIS, are connected with the solar energy absorbed by the plants, and iii) biophysical reasons determine the ratio between actual and potential efficiency of conversion of solar energy by the plants.
Based on this concept, and expressed very simple, the fraction of absorbed photosynthetically active radiation (FAPAR) can be linked via the efficiency of the plants to convert solar radiation into their growth, to estimate primary production. This conversion efficiency depends on biome type, LAI, and evapotranspiration & respiration conditions. Hence derivation of the two primary production parameters GPP and NPP offered here requires data about land cover, LAI, FAPAR, soil and atmospheric conditions as input as described in the User Guide.
The data sets (MODIS collection 6) offered here (NPP: MOD17A3H and GPP: MOD17AH2) have 8-daily (GPP) and annual (NPP) temporal resolution.
The data sets were included into the ICDC data holding on: November 25, 2016