46 45 Reference: R.E.Shetter et al. Actinometric and Radiometric Measurement and Modeling of the Photosylis Rate Coefficient of Ozone to O(1D) During MLOPEX II Journal of Geophysical Research, v 101 (D9), pg. 14,631-14,641, June 20, 1996 O3 + hv -> O2 + O(1D) "The measurements have been compared to modeled photolysis rate coefficients calculated using quantum yields from DeMore et al. [1994], from Michelsen et al. [1994], and from a reevaluation of the existing data. Indications from the comparison of many days of clear sky data are that quantum yields in the 312-320 nm range are not close to zero as suggested by DeMore et al. [1994] but closer to the data of Brock and Watson [1980] and Armerding et al. [1995], thus agreeing with the conclusions of Muller et al. [1995]. A recommendation for the quantum yield as a function of wavelength and temperature is made from our reevaluation of the existing data and fits well with the data taken at MLOPEX II." "At present, to obtain data at temperatures other than room temperature, the expressions of Adler-Golden and Michelsen are used (after multiplication by 0.95) to give Phi versus wavelength data at 230 K, and interpolations between 230 and 298 K are conducted using the following expression: Phi(lambda,T) = A(lambda) Exp[ -B(lambda)/T ] (11) Table 1 lists the recommended O(1D) quantum yields at 298 K and 230 K normalized to 0.95 at 305 nm and the A and B factors for extrapolating the data to other temperatures using the above equation." "Table 1: Recommended ozone photolysis O(1D) quantum yileds at 298 K and 230 K normalized to 0.95 at 305 nm and the A and B factors for extrapolating the data to other temperatures using Equation 11." [Comment: Table 1 has been extended by 'artificial' values of A and B from 280-306 nm to generalize the applicability of Phi=A*EXP(-B/T). Also, the recommended value at 260 nm has been included in the table. ***SF**] ------------------------------------------------------------------------------ Wavelength Phi(298) Phi(230) A B (nm) ------------------------------------------------------------------------------ 260 0.870 0.870 0.870 0.0 280 0.893 0.893 0.893 0.0 281 0.895 0.895 0.895 0.0 282 0.897 0.897 0.897 0.0 283 0.900 0.900 0.900 0.0 284 0.902 0.902 0.902 0.0 285 0.904 0.904 0.904 0.0 286 0.907 0.907 0.907 0.0 287 0.909 0.909 0.909 0.0 288 0.911 0.911 0.911 0.0 289 0.913 0.913 0.913 0.0 290 0.916 0.916 0.916 0.0 291 0.918 0.918 0.918 0.0 292 0.920 0.920 0.920 0.0 293 0.923 0.923 0.923 0.0 294 0.925 0.925 0.925 0.0 295 0.927 0.927 0.927 0.0 296 0.929 0.929 0.929 0.0 297 0.932 0.932 0.932 0.0 298 0.934 0.934 0.934 0.0 299 0.936 0.936 0.936 0.0 300 0.939 0.939 0.939 0.0 301 0.941 0.941 0.941 0.0 302 0.943 0.943 0.943 0.0 303 0.945 0.945 0.945 0.0 304 0.948 0.948 0.948 0.0 305 0.950 0.950 0.950 0.0 306 0.893 0.893 0.893 0.0 307 0.827 0.808 0.89 23.44 308 0.751 0.665 1.13 121.91 309 0.646 0.485 1.71 289.97 310 0.466 0.333 1.45 339.14 311 0.380 0.219 2.47 557.78 312 0.285 0.143 2.97 698.65 313 0.228 0.105 3.19 786.35 314 0.209 0.089 3.71 857.09 315 0.209 0.081 5.21 958.53 316 0.200 0.067 7.81 1093.04 317 0.181 0.061 7.16 1096.78 318 0.162 0.055 6.13 1083.90 319 0.133 0.038 9.21 1262.71 320 0.114 0.021 35.39 1709.92 321 0.095 0.018 26.14 1673.92 325 0.051 0.000 330 0.011 0.000