Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model
Item
Title (Dublin Core)
Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model
Description (Dublin Core)
The Whole Atmosphere Community Climate Model (WACCM) is utilised to study the daily ozone cycle and underlying photochemical and dynamical processes. The analysis is focused on the daily ozone cycle in the middle stratosphere at 5 hPa where satellite-based trend estimates of stratospheric ozone are most biased by diurnal sampling effects and drifting satellite orbits. The simulated ozone cycle shows a minimum after sunrise and a maximum in the late afternoon. Further, a seasonal variation of the daily ozone cycle in the stratosphere was found. Depending on season and latitude, the peak-to-valley difference of the daily ozone cycle varies mostly between 3 and 5% (0.4 ppmv) with respect to the midnight ozone volume mixing ratio. The maximal variation of 15% (0.8 ppmv) is found at the polar circle in summer. The global pattern of the strength of the daily ozone cycle is mainly governed by the solar zenith angle and the sunshine duration. In addition, we find synoptic-scale variations in the strength of the daily ozone cycle. These variations are often anti-correlated to regional temperature anomalies and are due to the temperature dependence of the rate coefficients <i>k</i><sub>2</sub> and <i>k</i><sub>3</sub> of the Chapman cycle reactions. Further, the NO<sub>x</sub> catalytic cycle counteracts the accumulation of ozone during daytime and leads to an anti-correlation between anomalies in NO<sub>x</sub> and the strength of the daily ozone cycle. Similarly, ozone recombines with atomic oxygen which leads to an anti-correlation between anomalies in ozone abundance and the strength of the daily ozone cycle. At higher latitudes, an increase of the westerly (easterly) wind cause a decrease (increase) in the sunshine duration of an air parcel leading to a weaker (stronger) daily ozone cycle.
Creator (Dublin Core)
Schanz, A.
Hocke, K.
Kämpfer, N.
Date (Dublin Core)
2018-09-11
Type (Dublin Core)
info:eu-repo/semantics/Text
Format (Dublin Core)
info:eu-repo/semantics/application/pdf
Identifier (Dublin Core)
10.5194/acp-14-7645-2014
https://acp.copernicus.org/articles/14/7645/2014/
Source (Dublin Core)
eISSN: 1680-7324
Language (Dublin Core)
eng
Relation (Dublin Core)
info:eu-repo/grantAgreement/EC/FP7/284421
Rights (Dublin Core)
info:eu-repo/semantics/openAccess
