Skip to main content

INTERACTIONS OF STRATOSPHERIC AEROSOLS AND TRACE GASES IN RELATION TO OZONE DEPLETION

Objective

This multidisciplinary project is aimed at investigating the physical and chemical processes involving particles of polar stratospheric clouds (and other stratospheric aerosols), and the potential role of these processes in the chemistry of the stratosphere.

The project will include the measurement of significant laboratory data for the development of models of aerosol catalysed reactions relevant to the depletion of ozone. The results will be confronted to the result of field measurements.

The main elements of the project are as follows:

In-situ measurements of stratospheric aerosols, trace gases and cluster ions with high resolution altitude measurements. Such vertically resolved profiles of concentration will allow the study of the formation and destruction of PSC particles as well as their roles in processing trace gases.
The second part consists of an extensive experimental programme concerning the thermodynamics and physico-chemistry of ice and hydrate particle. The aims are to understand and to quantify the different elementary steps leading to the conversion of passive to active chlorine molecules on stratospheric aerosols using laboratory simulation. The steps to be studied are the following: condensation and evaporation of ice and hydrate particles, sticking and adsorption of trace gases on particle surfaces, diffusion of hydrogen chloride into ice, heterogeneous reactions of ClONO2 and nitrogen pentoxide with water and HCl on ice or hydrate particles, and release of HOCl , chlorine and/or ClONO.
The third part is computer modelling of ice-catalysed reactions using classical trajectory calculations simulating chemical processes and reactions occurring on ice crystals. This approach is complementary to the experimental one to allow detailed understanding of the contribution of each elementary step in the overall process.

In order to evaluate the role of heterogeneous processes on ozone chemistry, vertical profiles of various key chemical species (simulated by model calculations using heterogeneous chemistry kinetic data) will be compared with in-situ measurements.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
Address
Rue Molière 54, Université De Grenoble 1
38402 Saint-martin-d'heres
France

Participants (3)

CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
France
Address
Avenue De La Recherche Scientifique 1 C
45071 Orleans
MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V.
Germany
Address
Saupfeicheckweg 1
69117 Heidelberg
THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF CAMBRIDGE
United Kingdom
Address
Trinity Lane, The Old Schools,
CB2 1TN Cambridge