Laboratory and field studies of oxidation processes occurring in the atmospheric marine boundary layer (OCEANO-NOX CEC project)
In: 1991; (1991)
Online
Elektronische Ressource
The atmospheric chemistry of the marine boundary layer has been investigated within the CEC OCEANO-NOX project funded by the Commission of the European Communities under contract n° EV4V 0075-C, This research area is integrated into the activities implemented within the COST project 611 "Physico-Chemicai Behaviour of Atmospheric Polluants". The OCEANO-NOX project combines laboratory kinetics studies, field measurements and chemical modelling. This research has been conducted by six collaborating groups : Harwell Laboratory (U.K.), CNRS Orleans (F), University of Wuppertal (FRG), KFA Jülich (FRG), University of Paris VII (F) and CFR Gif-sur-Yvette (F). Laboratory studies of the kinetics on the iodine chemistry and dimethyl sulphide (DMS) oxidation have been investigated by the first three groups, while the latter three have performed field measurements during two campaigns in 1988 and 1989 at the Pointe de Penmarc'h, a coastal area of Brittany with large natural emissions of DMS. This project has provided significant new insights of the chemical processes occurring in the atmospheric marine boundary layer. Concerning the iodine chemistry, it was particularly found from the laboratory studies that HOI may be an important reservoir of active iodine and that the DMS oxidation by the IO radical is definitely negligible under atmospheric conditions. Laboratory and field studies of the OH radical initiated (daytime) oxidation of DMS have shown that the CH3S03H/S02 increases in the presence of NOx. For the nighttime oxidation of DMS, the simultaneous field measurements of N03 and DMS for the first time, and the observation of vertical concentration gradients, indicate that the reaction of N03 with DMS is very likely to be the main loss process of both N03 and DMS when NOx polluted air advects over DMS source areas. It was also suggested from chemical modelling using these field data that the N03-DMS interaction could be a significant nighttime source of peroxy radicals. Some of the results obtained are important for the evaluation of the role of DMS oxidation in the climate - atmosphere interaction
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Laboratory and field studies of oxidation processes occurring in the atmospheric marine boundary layer (OCEANO-NOX CEC project)
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Autor/in / Beteiligte Person: | Commission, European |
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Quelle: | 1991; (1991) |
Veröffentlichung: | 1991 |
Medientyp: | Elektronische Ressource |
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