Production of O(1D) from photolysis of O3

We have used a model accounting for absorption by vibrationally and rotationally excited ozone (03) to examine published measurements of he quantum yield of O(•D) and O2(•Ag) from 03 photolysis in the Huggins band (305-325 nm). We conclude that the quantum yield of O(•D) is 0.2-0.3 for wavelengths between 312 and 320 nm at 298 K; in contrast, the JPL recommended quantum yield of O(•D) is negligible in this wavelength region. We present a compilation of our results at temperatures and wavelengths relevant to atmospheric calculations. Production f O(•D) from excited 03 increases calculated concentrations f O(•D) by up to 40% and OH by 15% for the troposphere and lower stratosphere. The temperature dependence of ß in the tail region provides a test of Hypothesis (3) since the population of 03 in vibrationally excited states falls with decreasing temperature. Data for ß in the tail region for temperatures lower than 298 K are only available from the low resolution experiment by Moortgat et al. [ 1977], measurements made by Lin and Demore [1973] at 233 K, and studies performed by Kuis et al. [1975] and Kajimoto and Cvetanovic • [1976] only at 313 nm. We have analyzed these data and those obtained at 298 K with a model that includes absorption by vibrationally and rotationally excited 0 3. The results confirm that •(298 K) exceeds 0.2 in the tail region. This model can be used to predict • at temperatures outside of the range 233-298 K.