Absolute rate constant for the reaction OH (v=0)+O3→HO2 +O2 over the temperature range 238–357 °K

The technique of laser flash photolysis–resonance fluorescence has been employed to measure absolute rate constants for the reaction OH (v=0)+O3→HO2+O2 over the temperature range 238–357 K. The results are described by the Arrhenius expression k =1.82+0.35−0.29×10−12 exp[(−930±50)/T] cc/molecule s. Extrapolation of this expression to 225 K, the temperature of the stratosphere in the region where O3 levels are highest, gives a rate constant which is ∼65% higher than the currently recommended value.