Estimation of global primary production using NOAA/NASA Pathfinder AVHRR land data set

A new global primary production model, GLO-PEM (GLObal Production Efficiency Model), is described. The current version is driven by the NOAA/NASA Pathfinder AVHRR Land Data Set which has a spatial resolution of 8×8 km for the entire land cover of the Earth but GLO-PEM can, in principle, use any AVHRR data set that includes channels 1, 2, 4, and 5. GLO-PEM calculates both gross and net primary production at the time step of the AVHRR data used-10 days in the case of the decadal Pathfinder data set. The new model is unique in that it infers all necessary variables from satellite observations. These variables include absorbed photosynthetically active radiation (APAR), the potential “efficiency” of conversion of APAR into biomass, plant respiration, air temperature, vapor pressure deficit and soil-moisture