Study of the quantum-yields of the products in the photolysis of ozone

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The quantum yield for 0(1D) production in the photolysis of ozone in the ultraviolet region as a function of wavelength and temperature is a key input for modeling calculations in the atmospheric chemistry. Ozone molecules have been photolysed in its strong photoabsorption band of the Hartley band at 230 - 308 nm and the 0(3Pj) photo fragments have been detected directly by a technique of laser-induced fluorescence around 130 nm. The quantum yield values for 0(1D) formation in the photolysis of ozone at 297 ± 2 K have been determined as a function of the photolysis wavelength, using the absolute 0(1D) quantum yield value of 0.79 at 308 nm as a reference. The 0(1D) quantum yield values obtained are found to be almost independent of the wavelength over the Hartley band (〜0.91). The results are compared with the values measured previously with various experimental techniques. The results are also compared with the recommendation values for use in atmospheric modeling. The relative production rates of 0(1D) from 03 photolysis in the stratosphere have been evaluated. We have shown that the 0(1D) production rates calculated with the 0(1D) quantum yield values obtained in this study are smaller than those calculated with the latest NASA/JPL recommendation by 1.9, 3.5 and 4.8 % , at the altitudes of 15, 25 and 40 km, respectively. On the other hand, the the 0(1D) production rates calculated with our 0(1D) quantum yield data are smaller than those with the IUPAC recommendation by 4.0 and 5.7 % at 15 and 25 km, respectively, and larger by 0.2 % at 40 km.