Atmospheric CO2 inversions at the mesoscale using data driven prior uncertainties. Part2: the European terrestrial CO2 fluxes

摘要

Optimized biogenic carbon fluxes for Europe were estimated from high resolution regional scaleinversions, utilizing atmospheric CO measurements at 16 stations for the year 2007. Additionalsensitivity tests with different data-driven error structures were performed. As the atmosphericnetwork is rather sparse and consequently contains large spatial gaps, we use a priori biosphericfluxes to further constrain the inversions. The biospheric fluxes were simulated by theVegetation Photosynthesis and Respiration Model (VPRM) at a resolution of 0.1° and optimizedagainst Eddy covariance data. Overall we estimate an a priori uncertainty of 0.54 GtC y relatedto the poor spatial representation between the biospheric model and the ecosystem sites. The sinkestimated from the atmospheric inversions for the area of Europe (as represented in the modeldomain) ranges between 0.23 and 0.38 GtC y (0.30 and 0.49 GtC y up-scaled to geographicalEurope). This is within the range of posterior flux uncertainty estimates of previous studies usingground based observations.