Impact of cloud-borne aerosol representation on aerosol direct and indirect effects

摘要: Aerosol particles attached to cloud droplets are much more likely be removed from the atmosphere and less efficient at scattering sunlight than if unattached. Models used estimate direct indirect effects of aerosols employ a variety representations such cloud-borne particles. Here we use global aerosol model with relatively complete treatment sensitivity simulated aerosol, radiation fields various approximations representation We find that neglecting transport introduces little error, but diagnosing produces mean biases 20% local errors up 40% for droplet number, radiative forcing. optical depth number significantly underestimated in regions seasons where when wet removal is primarily by stratiform rather convective clouds (polar during winter), biased because limited there then. A predicts total mass concentration each mode yields smaller runs faster treatment. The current estimates uncertainty aerosols, which suggests not significant source effects.