Sandy is a senior research fellow in the School of Chemistry. He is an expert in the kinetics of heterogeneous processes. In previous work he developed laboratory techniques to quantify the impact of aerosol on polar stratospheric clouds by measuring heterogeneous nucleation of nitric acid hydrate phases and water ice. This unique laboratory facility was used to show that meteoric smoke, produced by evaporation and recondensation of meteoric metals is sufficiently active to explain observed cloud, whilst fragments of unablated meteoroids are unlikely to contribute significantly. Sandy’s group also apply gas / surface flow tube techniques to quantify the effect of aerosol on gas phase chemistry, having examined for example uptake of HNO3 and catalysis of the self-reaction of HO2 by meteoric material in the middle atmosphere.
