The Reaction of Salt (NaCl) Particles with Nitrate Radical (NO3): A Potential Source of Nighttime Chlorine Compounds

University Of California-Irvine, Irvine CA

Investigators

Abstract

This project supports laboratory studies of the reaction of the nitrate radical (NO3) with salt (NaCl) particles. The objective of this work is to study possible nighttime mechanisms of chlorine (Cl2) production. Field studies have established that Cl2 (and perhaps other photochemically labile chlorine containing inorganics such as HOCl) are generated at night in coastal marine areas, however, none of the known processes can explain this phenomenon. Particles will be introduced into an aerosol chamber under conditions of temperature, pressure, and relative humidity relevant to the marine boundary layer. NO3 will be generated in situ, and the reactants and products monitored by FTIR and UV/VIS spectrometry and atmospheric pressure ionization spectrometry (APIMS). Experimental results will be interpreted using a computational kinetics model that includes gas and liquid diffusion, mass accommodation and chemistry in real time in both the gas and liquid phases, and where appropriate, the interface.