The Soil Moisture Active Passive (SMAP) “Gross Primary Production (L4, 9 km Grid Cell Mean, Model Value-Added)” layer displays global daily mean vegetation gross primary productivity (GPP) in grams of carbon uptake per meter squared per day (gC m-2 day-1) posted on a 9 km EASE-Grid 2.0. Gross Primary Production (GPP) is defined as the rate at which vegetation captures and stores carbon dioxide in a given length of time via a photosynthetic process.
The SMAP spacecraft carries two instruments, a radar (active) and a radiometer (passive), that together make global measurements of land surface soil moisture and freeze/thaw state. It is useful for monitoring and predicting natural hazards such as floods and droughts, understanding the linkages between Earth’s water, energy and carbon cycles, and reducing uncertainties in predicting weather and climate.
References: SMAP L4 Global Daily 9 km Carbon Net Ecosystem Exchange
Data field: gpp_mean