Abstract:
Soil moisture impacts atmospheric CO2 and CH4 exchange with vegetation and soils and plays an important role in the terrestrial carbon cycle. A better representation of the carbon-water-cycle coupling in terrestrial ecosystem models could potentially improve model estimates of large-scale carbon fluxes and climate feedbacks. Here we investigate using observations from the Soil Moisture Active Passive (SMAP) satellite mission to constrain carbon fluxes in the global terrestrial ecosystem model LPJ-wsl. Results suggest that SMAP assimilation reduces the bias in simulated soil moisture vs. in situ measurements. A wavelet analysis between the model and measurements from 26 FLUXNET sites suggests that assimilation can reduce the bias of simulated carbon fluxes for boreal sites at 30-70 day time scales. Better characterization of SMAP and model errors in soil moisture is needed to further enhance the use of SMAP measurements in global carbon cycle modeling.