Open AccessClimatologies of lower stratospheric NO y and O 3 and correlations with N 2 O based on in situ observations
Author(s) -
Strahan S. E.
Publication year - 1999
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jd900775
Subject(s) - stratosphere , atmospheric sciences , polar vortex , arctic , latitude , denitrification , environmental science , climatology , the arctic , altitude (triangle) , range (aeronautics) , chemical transport model , linear relationship , troposphere , nitrogen , physics , geology , mathematics , geometry , materials science , geodesy , oceanography , statistics , quantum mechanics , composite material
This paper presents NO y and O 3 seasonal mean distributions as a function of equivalent latitude and height from more than 140 ER‐2 flights. The observations span a height range of 360–530 K (∼150‐45 hPa) and have nearly pole‐to‐pole coverage in most seasons. These climatologies are intended to support efforts to evaluate the chemistry and dynamics of assessment models. Reasonable model representations of NO y , O 3 , and their seasonal variations are necessary to assess the effects of aircraft exhaust on the stratosphere. ER‐2 measurements of N 2 O are combined with the NO y data to examine their lower stratospheric relationship and to identify regions of denitrification. Measurements of these species above ER‐2 altitudes in the Arctic vortex support the interpretation of some of the ER‐2 NO y ‐N 2 O data, which suggest that transport rather than chemical denitrification causes deviations from the normally linear relationship. This places constraints on the use of a linear relationship to calculate denitrification. The observed relationship between N 2 O and O 3 is also presented. The spatial gradients in lower stratospheric O 3 photochemistry are used to explain observed variations in the N 2 O‐O 3 relationship. The N 2 O‐O 3 relationship above ER‐2 altitudes in the Arctic vortex, much like the case of NO y ‐N 2 O, also differs in slope from lower altitudes. This points to the difficulties in using tracer correlations to infer O 3 values in the vortex prior to polar stratospheric cloud processing. It is necessary to understand the photochemical and transport history of the air that descends into the lower stratospheric vortex in order to correctly quantify O 3 depletion.