Impacts of aerosol dry deposition on black carbon spatial distributions and radiative effects in the Community Atmosphere Model CAM5

Black carbon (BC) plays an important role in the Earth's climate, but is subject to large bias in remote regions in model simulations. In this study, to improve the BC simulations, the scheme of Petroff and Zhang () (PZ10) is implemented into the Community Atmospheric Model version 5 (CAM5), and model simulations using PZ10 are compared with the one using the default scheme of Zhang et al. () (Z01) and observations.

The PZ10 scheme predicts much lower dry deposition velocity (V-d) than Z01 for fine particles in Aitken, primary carbon, and accumulation modes, resulting in 73.0% lower of global mean BC dry deposition fluxes and 23.2% higher of global mean BC column burdens. CAM5 with PZ10 increases modeled BC concentrations at all altitudes and latitudes compared to Z01, which improves the agreement with observations of BC profiles in the lower troposphere in the Arctic.