Atmospheric loss of nitrous oxide (NO) is not influenced by its potential reactions with OH and NO radicals

• Published in: Physical chemistry chemical physics : PCCP Vol. 21; no. 44; pp. 24592 - 246
• Main Authors: Ravishankara, A. R, Pele, Anne-Laure, Zhou, Li, Ren, Yangang, Zogka, Antonia, Daële, Véronique, Idir, Mahmoud, Brown, Steven S, Romanias, Manolis N, Mellouki, Abdelwahid
• Format: Journal Article
• Published: 13.11.2019
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c9cp04818a

The rate coefficient for the possible reaction of OH radical with N 2 O was determined to be k 1 < 1 × 10 −17 cm 3 molecule −1 s −1 between 253 and 372 K using pulsed laser photolysis to generate OH radicals and pulsed laser induced fluorescence to detect them. The rate coefficient for the reaction of NO 3 radical with N 2 O was measured to be k 2 < 5 × 10 −20 cm 3 molecule −1 s −1 at 298 K using a direct method that involves a large reaction chamber equipped with cavity ring down spectroscopic detection of NO 3 and N 2 O 5 . Various tests were carried out ensure the accuracy of our measurements. Based on our measured upper limits, we suggest that these two reactions alter the atmospheric lifetime of N 2 O of ∼120 years by less than 4%. The rate coefficient for the possible reaction of OH and NO 3 radical with N 2 O are shown to be, respectively, <1 × 10 −17 and <5 × 10 −20 cm 3 molecule −1 s −1 . They are too low to contribute significantly to the atmospheric removal of N 2 O.