Global inversions of black carbon emissions using TM5-MP coupled with CTDAS

Black Carbon (BC) aerosol is a major short-lived climate forcer which plays a significant role in both atmospheric warming and air quality. BC is emitted during incomplete combustion during fossil fuel combustion, biomass burning and domestic heating but its emission fluxes estimate remains uncertain. The accurate representation of BC fluxes and its atmospheric fate in climate models is crucial for understanding BC contribution to climate change. This study aims to optimize the total BC emissions, using as starting point the emission inventories provided by CMIP6 for both anthropogenic and biomass burning sources. For this, a data assimilation global 3-d modeling system was used together with filter and aethalometer measurements of BC worldwide. The assimilation system used is the forward chemistry and transport model TM5-MP combined with the Carbon Tracker Data Assimilation Shell (CTDAS) that utilizes an Ensemble Kalman filter data assimilation method. The TM5-MP model simulates atmospheric chemistry and aerosol microphysics using the M7 module in the global atmosphere driven by ERA-5 meteorology and running with a 2^ox3^o horizontal resolution and 25 hybrid levels up to 0.1 hPa. The efficiency of the optimisation method is evaluated by comparing the forward simulations with the aerosol optical depth observations from the AERONET network before and after the emission optimization.