Kinetics and mechanism of the heterogeneous interaction of ozone with soot aerosol

Abstract

INTRODUCTION Atmospheric soot concentrations typically range from 0.002 μg/m3 in the stratosphere up to 40 μg/m3 in the polluted urban troposphere. Due to its irregular agglomerate structure soot aerosol offers a large surface for interactions with reactive trace gases like ozone. Recent model results indicated a possible effect of the soot ozone interaction on tropospheric (Bekki et al., 1997) and stratospheric ozone concentrations (Lary et al., 1997). However, the model predictions are uncertain because they rely on soot surface reaction probabilities mainly measured on short time scales (seconds to minutes) using bulk soot samples and high surface to trace gas concentration ratios, thus being not directly comparable to atmospheric conditions.