Skip to Main content Skip to Navigation
Theses

Développement d'une chaîne automatique d'écriture de schémas chimiques explicites et réduits adaptés à l'étude de la pollution photooxydante aux différentes échelles

Abstract : Millions of compounds are involved in atmospheric chemistry. Chemical schemes must then be reduced to model the photo-oxidant pollution using chemistry-transport models (CTM). Such reduced schemes describe the atmospheric VOC oxidation using typically a hundred of species. The reduction methods depend actually on the particular case under consideration.
The recent emergence of multi-scale CTM sets the problem of the use of reduced chemical schemes developed for a specified scale to the simultaneous modeling of several space scales.

The objective of this work was to develop and assess an automatic procedure allowing to write explicit and reduced chemical schemes suited to the study of photo-oxidant pollution at different scales. The method is based on (1) the development of a tool dedicated to the writing of explicit schemes for VOC oxidation and (2) the assessment of reduced schemes using the explicit scheme as a reference.

In order to minimize the problems involved in the development of chemical schemes, an automatic generator of explicit chemical schemes was developed for the tropospheric VOC oxidation. This generator is based on state of the art in terms of reactivity and mechanisms. It allows the writing of the whole set of reactions implied in the oxidation of a given primary compound, from its initiation to its total oxidation in CO2 et H2O.

A reference chemical scheme was built, using the generator, for about seventy primary VOC, chosen to be representative of both anthropogenic and biogenic emissions. The scheme describes their oxidation through more than 2 millions of reactions and 350.000 species.

Three methods were applied to reduce the size of the chemical scheme: (i) use of operators, based on the redundancy of inorganic chemistry implied in the VOC oxidation, (ii) lumping of primary species having similar reactivities and (iii) lumping of secondary products into surrogate species. The number of species in the final reduced scheme is 150, i.e. low enough for 3D modeling purposes using CTM. Tests were carried out with a box model for several typical tropospheric conditions. These tests showed the capacity of the reduced chemical scheme to accurately model the ozone and oxidant chemistry in various tropospheric situations, from polluted to remote conditions.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-00006599
Contributor : Sophie Laval-Szopa <>
Submitted on : Wednesday, July 28, 2004 - 11:59:42 AM
Last modification on : Tuesday, September 1, 2020 - 5:30:05 PM
Long-term archiving on: : Friday, April 2, 2010 - 8:22:03 PM

Identifiers

  • HAL Id : tel-00006599, version 1

Citation

Sophie Laval-Szopa. Développement d'une chaîne automatique d'écriture de schémas chimiques explicites et réduits adaptés à l'étude de la pollution photooxydante aux différentes échelles. Océan, Atmosphère. Université Paris XII Val de Marne, 2003. Français. ⟨tel-00006599⟩

Share

Metrics

Record views

359

Files downloads

819