Improved Representation of the Reaction of N2O5 on Aerosols for Mesoscale Air Quality Models

摘要

An important mechanism for the conversion of NO2 to HNO3, and hence the termination of photochemically active NOx, involves nighttime reactions of NO3 and N2O5. A key step in this chemical pathway is the heterogeneous reaction of N2O5 with H2O to form HNO3. The rate of this reaction has been found to be proportional to the surface area of ambient wetted aerosols. The paper describes a simple technique for estimating the rate of this reaction using sulfate concentration and relative humidity to estimate aerosol surface area. The scheme for computing the N2O5 rate coefficient is tested in the Regional Acid Deposition Model (RADM).