Evidence for new sulfate particle formation in the remote troposphere involving biogenic trace gas species

Abstract

Findings from earlier field studies (Weber et al., 1995; Weber et al., 1997) showed that rates of new particle formation in the remote troposphere can be significantly higher than those predicted by classical heteromolecular sulfuric acid water (H$04-H20) nucleation theory (Jaecker-Voirol and Mirabel, 1989). We have speculated that higher rates may be due to the participation of ammonia (NH3) through a ternary mechanism involving H#04-NH3Hz0 (Weber et al., 1996). Airborne measurements made in the vicinity of Macquarie Island during the first Aerosol Characterization Experiment (ACE 1) support the hypothesis that participation of additional species can result in particle formation rates that significantly exceed rates for H$S04-Hz0 nucleation (Weber et al., 1998a).