SOLAR PHOTOLYSIS OF OZONE TO SINGLET D OXYGEN-ATOMS

The ground level photolysis frequency of ozone J(O3) to produce metastable singlet D oxygen atoms (O(1D)) has been measured using a novel instrumental technique involving electrical conductivity. The O(1D) atoms produced react with nitrous oxide (N2O) carrier gas to form higher oxides of nitrogen (NOx). These oxides (NOx) were detected by mixing with methanol and determining the increase in electrical conductivity with a continuous flow dual conductivity cell. Over 70 days of data were collected under varying sky conditions. The effect of temperature on J(O3) was measured. The results agree with model predictions. The effects of atmospheric aerosols, changes in overhead ozone column, and local cloudiness are discussed.