Kinetics of reactions of ground state nitrogen atoms (4S3/2) with NO and NO2

Abstract

The discharge flow technique has been used with resonance fluorescence detection of N atoms to study the fast radical-radical reaction of ground state nitrogen atoms (4S3/2) with NO and NO2. The rate constants obtained are (in units of cm3 molecule-1s-1) k1=(2.2±0.2)×10-11exp[(160±50)/T] in the temperature range 213 K ≤ T ≤ 369 K for N + NO → N2 + O and k2 = (5.8±0.5)×10-12 exp[(220±50)/T] in the temperature range 223 K ≤ T ≤ 366 K for N + NO2 → N2O + O. The reaction kinetics are consistent with other radical-radical reactions. Substitution of the measured rate of R1 for the value recommended in the latest Jet Propulsion Laboratory compendium results in a small change in the concentration of ozone predicted in a two-dimensional photochemical model. Modeled ozone concentrations are higher (approximately 1%) in the high-latitude upper stratosphere as a result of a 3-10% reduction in the calculated concentrations of NOy . -from Authors