Impact of new laboratory studies of N₂O₅ hydrolysis on global model budgets of tropospheric nitrogen oxides, ozone, and OH

Abstract

We investigate the impact of new laboratory studies of N 2 O 5 hydrolysis in aerosols on global model simulations of tropospheric chemistry. We use data from these new studies to parameterize the reaction probability (γ N2O5 ) in the GEOS‐CHEM global model as a function of local aerosol composition, temperature, and relative humidity. We find a much lower global mean γ N2O5 (0.02) than commonly assumed in models (0.1). Relative to a model simulation assuming a uniform γ N2O5 = 0.1, we find increases in mass‐averaged tropospheric NO x , O 3 , and OH concentrations of 7%, 4%, and 8% respectively. The increases in NO x and O 3 concentrations bring the GEOS‐CHEM simulation in better agreement with climatological observations.