Extraordinary isotopic fractionation in ozone photolysis

[1] Analysis of experimental ozone absorption spectra reveals that ultraviolet photolysis within the structured Huggins band yields extraordinary wavelength-dependent isotopic fractionation, oscillating between complete enrichment and complete depletion for changes of less than 2 nm in the excitation wavelength. Visible photolysis yields wavelength-dependent fractionation that varies from 300% to +300%. Photochemical modeling demonstrates photolysis contributes fractionation up to +45% to the heavy ozone anomaly in the middle stratosphere with measurable O and O isotopologue-dependent variations as a function of altitude despite the fact that the extraordinary photolysisinduced isotopic fractionation effect is dampened in the atmosphere due to the integration over all excitation wavelengths. Citation: Miller, C. E., R. M. Onorato, M.-C. Liang, and Y. L. Yung (2005), Extraordinary isotopic fractionation in ozone photolysis, Geophys. Res. Lett., 32, L14814, doi:10.1029/ 2005GL023160.