Diurnal variations of minor constituents in the stratosphere modeled as a function of latitude and season

Abstract

Photodissociation and collision processes in the atmosphere cause significant diurnal variations of short‐lived minor constituents, in particular among the group of catalysts HOx, NOx, and ClOx. Results of diurnal variation experiments within the framework of the Oxford zonally averaged model are presented. With 49 collision reactions and 13 photodissociation reactions, the model incorporates the most important processes known at present. The model extends from pole to pole and from the surface to about 60 km with a resolution of π/19 in the horizontal (∼9.5°) and half a pressure scale height in the vertical (∼3.5 km). The basic time increment for the integration is 5 min. Results are compared with experimental data.

Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model

“…The present study shows that the global view of WACCM on the daily ozone cycle is invaluable for understanding and planning a correction method. Generally, the results of WACCM are in good agreement with previously reported results of photochemical box models at northern midlatitudes (Herman, 1979;Fabian et al, 1982;Pallister and Tuck, 1983). WACCM and the box models show a daily cycle of stratospheric ozone with a 1 % decrease after sunrise and a slow ascent to approximately 3-5 % in the late afternoon (similar to Fig.…”

“…Pallister and Tuck (1983) modelled the diurnal ozone cycle at 34 • N with a photochemical box model and confirmed the results of Herman (1979). Furthermore, Fabian et al (1982) indicated latitudinal and seasonal effects by utilisation of a two-dimensional, zonally averaged model. At that time the model utilised by Fabian et al (1982) did not couple dynamics and diurnal photochemistry.…”

“…Pallister and Tuck, 1983;Herman, 1979;Fabian et al, 1982) indicate a strong connection to chemistry and photochemistry. In this section, we analyse WACCM simulations of chemical and photochemical processes under their coupling to dynamics and the thermal state of the atmosphere.…”

“…At that time the model utilised by Fabian et al (1982) did not couple dynamics and diurnal photochemistry. Observations as rocket-based measurements of day-and night-time ozone (Lean, 1982) and balloon-borne measurements (Aimedieu et al, 1981) seemed to support the simulation results of Fabian et al (1982); Herman (1979) and Pallister and Tuck (1983). However, quality and sampling of the few measurements were not sufficient to give observational evidence for the small, daily cycle of stratospheric ozone.…”

“…Furthermore, Fabian et al (1982) indicated latitudinal and seasonal effects by utilisation of a two-dimensional, zonally averaged model. At that time the model utilised by Fabian et al (1982) did not couple dynamics and diurnal photochemistry. Observations as rocket-based measurements of day-and night-time ozone (Lean, 1982) and balloon-borne measurements (Aimedieu et al, 1981) seemed to support the simulation results of Fabian et al (1982); Herman (1979) and Pallister and Tuck (1983).…”