Ozone and water vapor in the troposphere
Centre Européen de Recherche et de Formation Avancée en Calcul Scientifique42, Avenue Gaspard Coriolis
31057 Toulouse Cedex
Tel : 05 61 19 31 31 - Fax : 05 61 19 30 00
OZONE AND WATER VAPOR IN THE TROPOSPHERE
Dieter Kley
(Institut Pierre-Simon Laplace des Sciences de L'Environnement Global Université Pierre-et-Marie Curie, Paris)
(On leave of absence from Forschungszentrum Julich and Universitat Wuppertal, Germany)
Thursday April 2, 11.00 a.m. CERFACS Conference Room
Ozone is not a photochemically stable trace gas in the troposphere. Its lifetime is as short as 3-5 days in the tropical planetary boundary layer. The classical view on the origin of tropospheric ozone held that transfer from the stratosphere was the only source where it is produced by oxygen photodissociation.
However, photochemical production from reduced, carbon-containing, trace gases in the presence of oxides of nitrogen provides a tropospheric source of ozone.
The upper troposphere is receiving considerable attention with regard to the ozone budget question because ozone in this altitude regime exhibits a significant greenhouse effect. Furthermore, commercial and military aviation, through emission of oxides of nitrogen, is thought to contribute to the production of ozone at cruise altitudes which, in turn, in the way of atmospheric transport to lower altitudes, could influence the ozone background concentration even in the planetary boundary layer.
The seminar is concerned with results from the MOZAIC project, an experimental approach to measure water vapor and ozone simultaneously on board of scheduled passenger aircraft. The talk will concentrate on the Atlantic region form 40-60=B0N. One year (1995) of at least daily flights between Europe and U.S.A. will be statistically analysed. The analysis will focus on the tropospheric part of the data set. Conclusions will be drawn as to the origin of upper tropospheric ozone.
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