CO Flux Inversion with Assimilation of MOPITT and IASI Observations in the Northern America Biomass Burning Plumes

Accurate representations of the location and magnitude of CO surface emissions are required to accurately quantify the global CO flux signal. The global coverage and the high resolution of satellites measuring CO by infrared remote sensing allow to improve our ability to map CO and to understand its variability. Among these orbiting instruments, there are the Measurements of Pollution in the Troposphere (MOPITT) from satellite TERRA and the Infrared Atmospheric Sounding Interferometer (IASI) on board satellite Metop-A. The advantage of using MOPITT is that it has a higher sensitivity in the lower troposphere than IASI.

In this presentation, we will demonstrate the potential of the MOPITT – IASI CO assimilation for qualitatively constraining the CO emissions from biomass burning sources over the Northern America for the 2008-2016 period. We will focus our study on biomass burning occurring over California and boreal forests in Canada. CO column retrievals from MOPITT v7 and IASI-FORLI are assimilated jointly. We apply a 4D-VAR data assimilation system using the 6°x4° global version of the chemistry transport model TM5.

Combination of IASI and MOPITT assimilated in TM5 allows hence an accurate vertical structure in the troposphere and a better exploitation of CO emissions. Validation against the Total Carbon Column Observing Network (TCCON) shows good agreement of CO flux magnitude and variability. The assimilation of IASI and MOPITT improves CO estimations and allows to accurately observe CO magnitudes and variability of forest fires plumes.