Radiative Forcing from Carbonaceous Emissions

Black Carbon particles are emitted as primary particles from incomplete combustion process, such as fossil fuel and biomass burning. Organic carbon particles are released in the atmosphere both from primary emissions and secondary emission of gaseous compounds via condensation or gas phase oxidation of hydrocarbons. Black carbon aerosols absorb the solar radiation and induce positive forcing whereas organic matter aerosols reflect solar radiation and produce negative forcing. Direct radiative forcing at the top of the atmosphere (TOA) for black carbon aerosols from these two inventories comes out to be +0.33 W/m2 (GEIA) and +0.14 W/m2 (Bond et al. 2004) respectively. However, for organic matter aerosols, it is simulated as -0.44 W/m2 for GEIA and -0.11 W/m2 with the inventory of Bond et al. (2004). In the present study we have compared the annual global burden, aerosol optical depth (AOD) and direct radiative forcing of carbonaceous aerosols using two emission inventories with the help of the general circulation model of the Laboratoire de Météorologie Dynamique (LMD). Normalised difference plots clearly show that with GEIA inventory model simulates generally higher values carbonaceous aerosols which are far superior in some parts of the globe in comparison to the BOND emission inventory.