EVOLUTION OF THE SUBTROPICAL MARINE BOUNDARY-LAYER - PHOTOCHEMICAL OZONE LOSS

A diurnally averaged ozone decay rate of about 0.11 day(-1) was observ ed under partly cloudy sky in the boundary layer over the eastern Atla ntic during the second Lagrangian experiment in the Atlantic Stratocum ulus Transition Experiment. The observed decay rate can be accounted f or by the combined effects of ozone loss through photolysis by UV radi ation, reaction with HO2 radical, and deposition on the sea surface, a nd effects of ozone production through photooxidation of carbon monoxi de and methane in the presence of nitrogen oxides. The main contributo r to the ozone decay is photolysis by UV radiation, but the other sour ces and sinks also make significant contributions.