The Effective Radiative Forcing Due to Partly Internally Mixed and Externally Mixed Anthropogenic Aerosols and Their Effects on Global Climate

The total effective radiative forcing (ERF) of partly internally mixed (PIM) anthropogenic aerosols by considering the aerosol-cloud interaction since the pre-industrial times and their effects on global climate have been estimated by using an aerosol-climate online coupled model of BCC_AGCM2.0_CUACE/Aero and compared with externally mixed (EM) aerosols in this work. The total global mean ERF since the pre-industrial was thus obtained to be -1.02 W m^-2 including -0.85 W m^-2 of ERF_aci and -0.17 W m^-2 of ERF_ari for PIM case, and -1.68 W m^-2 including -1.38W m^-2 of ERF_aci and -0.30W m^-2 of ERF_ari for EM case, respectively. The global annual mean surface temperature, water evaporation and precipitation have been accordingly reduced for 0.99 K, 0.08 mm day^-1, 0.09 mm day^-1 in PIM case, and 1.84K, 0.14 mm day^-1, 0.15 mm day^-1 in EM case, respectively. However, the relative humidity near the surface was slightly increased in both cases. The Hadley circulation was suppressed due to the cooling effect of anthropogenic aerosols, and the intertropical convergence zone has been southwardly moved in both cases and thus the equatorial precipitation zone. In conclusion, the internal mixing could greatly reduce the negative ERF and cooling effect of anthropogenic aerosol.