Estimation of Gross Primary Production from Space
Biomass production of terrestrial ecosystems
Gross primary production (GPP) in terrestrial ecosystems refers to the total amount of carbon fixed by plants in the process of photosynthesis in a given length of time, part of which is eventually accumulated as biomass. LSA SAF's satellite product Gross Primary Production (MGPP, LSA-411) is produced from MSG data every 10 days. Its inputs are the daily integrated down-welling surface shortwave radiation flux (DIDSSF, LSA‐203), the daily fraction of absorbed photosynthetically active radiation (MDFAPAR, LSA‐425) and the actual and reference evapotranspiration (DMET, LSA-302; DMETREF, LSA-303) LSA- SAF products. Terrestrial primary production is normally most important in the fields related to forestry management. In this sense, satellite derived data provide a reliable spatial and temporal coverage of GPP whereas in-situ measurements of primary production are often quite limited.
The figures to the left display terrestrial GPP in April-December 2018 over Europe, Africa and South America. Desert areas and areas with frequent cloud cover are masked (e.g. coastal parts of Central as well as West Africa and North Europe). GPP maximum values are reached over parts of equatorial Central Africa and South America (the Congo and the Amazon rainforests) owing to warm temperature, moist and radiation availability. Shorter growth season due to colder temperatures and moderate radiation causes the northern latitudes to experience lower GPP. The semi arid regions, e.g., SE Spain, Sahel, East and South Africa show the lowest GPP values. We can observe also that GPP in tropical rainforests of equatorial regions (2.3 kg/m2) is nearly twice as much as that of European temperate forests (1.3 - 1.4 kg/m2). GPP is even lower in the boreal forests, savannahs and cultivated lands ranging in 0.6 - 0.9 kg/m2.