Constraining the Eurasian biogenic boreal carbon-cycle with satellite-SIF

The Eurasian boreal ecosystem acts as a major terrestrial carbon sink in the northern hemisphere. Under changing climatic conditions, it is crucial to monitor biogenic carbon fluxes in this area. The Siberian in-situ CO₂ data are, however, sparse in spatial coverage and limit model-validation there. Satellite observations of CO₂ and Sun-Induced Fluorescence (SIF) can provide essential information to constrain the Eurasian boreal biogenic carbon-cycle and further, to improve carbon cycle inverse models.

In this study, we investigate the Eurasian boreal carbon cycle with satellite observations of the Orbiting Carbon Observatory 2 (OCO-2) and the Greenhouse gase Observing SATellite (GOSAT). We compare the observed carbon cycle dynamics to model data such as provided by CarbonTracker (CT2019, CT-NRT.v2020-1) and find differences in the ppm range. Various sensitivity studies with respect to region selection, sampling biases and model choices are used to consolidate the robustness of the detected pattern. Using SIF and FLUXCOM GPP data, we will show first attempts to attribute the model-measurement differences to uncertainties in biogenic carbon fluxes.