A preliminary study of the effect of ammonia on particle nucleation in the marine boundary layer

Abstract

A ternary nucleation model for the H 2 SO 4 ‐NH 3 ‐H 2 O system is presented in an effort to examine the effect of NH 3 on heteromolecular homogeneous nucleation in the marine boundary layer (MBL). The results from this nucleation model suggest that ammonia could, in fact, enhance the nucleation rate over that of the binary system, H 2 SO 4 ‐H 2 O. The magnitude of this enhancement is introduced as an enhancement ratio, which, in principle, is applicable to any binary nucleation rate for H 2 SO 4 ‐H 2 O. Also presented are preliminary results from a simple aerosol model using this enhancement ratio. These results suggest that under conditions typical of the marine environment it may be possible to produce enough particles to balance the various particle sinks characteristic of the MBL.