The sensitivity of regionally averaged O3 and SO2 concentrations to ADOM dry deposition velocity parameterizations

The influence of three different surface resistance formulations upon the resulting grid-averaged dry deposition velocity and the concentrations of O₃ and SO₂ calculated using the Acid Deposition and Oxidant Model (ADOM) has been investigated. Four ADOM simulations of the O₃ and SO₂ concentrations were compared with each other and the observations. The results show that two of the resistance formulations can decrease the original ADOM area-averaged dry deposition velocity by as much as 50% and increase the corresponding concentration by as much as 37% for O₃ and SO₂. However, all versions of the ADOM considerably underpredict the concentrations, implying weaknesses in ADOM that are not related to dry deposition. Wet surfaces appeared to have little influence on the estimated dry deposition velocity and concentration of O₃ but had a strong influence on those for SO₂.