Quantum yields of O(1D) formation in the photolysis of ozone between 230 and 308 nm -: art. no. 4440

Ozone molecules are photolyzed in the strong photoabsorption band of the Hartley band at 230-308 nm, and the O(P-3(j)) photofragments produced by the photolysis are detected directly by a technique of laser-induced fluorescence around 130 nm. The quantum yield values for O( 1 D) formation in the photolysis of ozone at 297 +/- 2 K are determined as a function of the photolysis wavelength, using the O(D-1) quantum yield value of 0.79 at 308 nm as a reference. The O(D-1) quantum yield values obtained are found to be almost independent of the photolysis wavelength over the Hartley band (similar to0.91). The results are compared with the values measured previously using various experimental techniques and also with the recommendation values for use in atmospheric modeling. The effects of the present yield data on the O(D-1) production rates from ozone photolysis in the stratosphere are evaluated. Impact of our new O(D-1) quantum yield values on the stratospheric chemistry has also been explored using a one-dimensional photochemical model. The smaller O(D-1) production rates as compared to the latest NASA/JPL recommendation values are followed by changes in the efficiency of the chemical chain reactions involving HOx, NOx, and ClOx and result in the higher O-3 concentrations throughout the stratosphere.