Atmospheric Chemistry and Physics Regional-scale geostatistical inverse modeling of North American

Abstract. A series of synthetic data experiments is per-formed to investigate the ability of a regional atmospheric in-version to estimate grid-scale CO2 fluxes during the growing season over North America. The inversions are performed within a geostatistical framework without the use of any prior flux estimates or auxiliary variables, in order to focus on the atmospheric constraint provided by the nine towers col-lecting continuous, calibrated CO2 measurements in 2004. Using synthetic measurements and their associated concen-tration footprints, flux and model-data mismatch covariance parameters are first optimized, and then fluxes and their un-certainties are estimated at three different temporal resolu-tions. These temporal resolutions, which include a four-day average, a four-day-average diurnal cycle with 3-hourly in-crements, and 3-hourly fluxes, are chosen to help assess th