How well can TROPOMI satellite measurements constrain methane emissions? An OSSE study for North America using the GEOS-Chem adjoint model

Abstract:

The TROPOMI satellite sensor dramatically expands our ability to characterize the distribution of atmospheric methane at high spatial and temporal resolution. In this study, we perform a series of Observation System Simulation Experiments (OSSEs) with the GEOS-Chem adjoint model (nested at 25km over North America) to quantify the ability of this new dataset to constrain methane emissions. This presentation will explore the degree to which prior emission biases can be corrected, and at what spatial resolution, for time windows ranging from 1-day to 1-month. We further assess the importance of instrument error, coverage limitation due to clouds, and model transport errors in restricting inversion fidelity. Finally, given limitations of standard scale-factor inversions for correcting missing or mis-located sources, we compare alternate optimization frameworks in terms of their ability to correct such errors.