The MODIS Aqua MYD17A2H Version 6.1 product provides an 8-day cumulative composite of Gross Primary Productivity (GPP) at 500 m spatial resolution. The dataset is based on the radiation use efficiency concept and can be used as input for models analyzing terrestrial energy balance, carbon and water cycles, and vegetation biogeochemistry. In addition to GPP, the product includes Net Photosynthesis (PSN), calculated as GPP minus Maintenance Respiration (MR). The dataset also contains a PSN Quality Control (QC) layer that provides quality information for both the GPP and PSN variables.