Premium
The effectiveness of N 2 O in depleting stratospheric ozone
Author(s) -
Revell Laura E.,
Bodeker Greg E.,
Smale Dan,
Lehmann Ralph,
Huck Petra E.,
Williamson Bryce E.,
Rozanov Eugene,
Struthers Hamish
Publication year - 2012
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2012gl052143
Subject(s) - ozone , stratosphere , ozone layer , ozone depletion , atmospheric sciences , oxygen , environmental science , atomic oxygen , yield (engineering) , chlorine , climatology , environmental chemistry , chemistry , physics , geology , thermodynamics , organic chemistry
Recently, it was shown that of the ozone‐depleting substances currently emitted, N 2 O emissions (the primary source of stratospheric NO x ) dominate, and are likely to do so throughout the 21st century. To investigate the links between N 2 O and NO x concentrations, and the effects of NO x on ozone in a changing climate, the evolution of stratospheric ozone from 1960 to 2100 was simulated using the NIWA‐SOCOL chemistry‐climate model. The yield of NO x from N 2 O is reduced due to stratospheric cooling and a strengthening of the Brewer‐Dobson circulation. After accounting for the reduced NO x yield, additional weakening of the primary NO x cycle is attributed to reduced availability of atomic oxygen, due to a) stratospheric cooling decreasing the atomic oxygen/ozone ratio, and b) enhanced rates of chlorine‐catalyzed ozone loss cycles around 2000 and enhanced rates of HO x ‐induced ozone depletion. Our results suggest that the effects of N 2 O on ozone depend on both the radiative and chemical environment of the upper stratosphere, specifically CO 2 ‐induced cooling of the stratosphere and elevated CH 4 emissions which enhance HO x ‐induced ozone loss and remove the availability of atomic oxygen to participate in NO x ozone loss cycles.