EUROSOLVE: Improved understanding of stratospheric ozone loss by collaboration with the sage iii ozone loss and validation experiment

• Unité de recherche: PCRD EU
• Numéro de projet: 99.0218-2
• Titre du projet anglais: EUROSOLVE: Improved understanding of stratospheric ozone loss by collaboration with the sage iii ozone loss and validation experiment

Mots-clé (Anglais)

Ozone depletion; polar stratospheric clouds; gravity waves; denitrification; trajectories

Programme de recherche (Anglais)

EU-programme: 5. Frame Research Programme - 1.4a.2 Global change, climate and biodiversity

Description succincte (Anglais)

See abstract

Partenaires et organisations internationales (Anglais)

Coordinator: Norsk institutt for luftforskning, Kjeller (N)

Résumé des résultats (Abstract) (Anglais)

The EU project EuroSOLVE aimed at increasing our understanding of the chemical ozone depletion in the Arctic stratosphere. More than 20 partners were involved and contributed to an extensive field campaign in Kiruna during the winter 199912000 (together with the American SOLVE project), and to the analysis and theoretical interpretation of the observed experimental data. The winter 1999/2000 was characterized by extremely cold temperatures, several episodes of strong gravity wave activity and mountain wave PSCs (polar stratospheric clouds) over the Scandinavian mountains, the in-situ observation of very large NAT aerosols which led to a significant denitrification of the Arctic stratosphere, and eventually severe ozone depletion, in particular in the lower stratospheric layers from 400 to 550k.
The main activities of the ETH group for the EuroSOLVE project can be summarized in three strongly inter-related topics: (i) mesoscale weather prediction (NWP) models with a horizontal resolution of 15km were operated during and after the field campaign in order to provide detailed temperature forecasts (including the effects of vertically propagating mountain waves) for the lower stratosphere; (ii) very detailed microphysical box modelling of PSCs air parcels along trajectories computed with the output from the NWP models; and (iii) the implementation and application of an aerosol particle trajectory tool (including the growth and sedimentation of the particles) to study the life-cycle of the observed large NAT particles. Activity (i) yielded valuable high-resolution wave activity and temperature forecasts and served as a prerequisite for activity (ii) where it was possible for the first time to use unmodified NWP model output to accurately simulate the microphysics of mesoscale PSCs. Finally activity (iii) led to a careful and novel Lagrangian investigation of mechanisms that might be responsible for the formation of the very large NAT aerosols. This issue constitutes one of the keys for the understanding of the present state and future development of the Arctic stratospheric ozone layer.

Références bases de données (Anglais)

Swiss Database: Euro-DB of the
State Secretariat for Education and Research
Hallwylstrasse 4
CH-3003 Berne, Switzerland
Tel. [phone]
Swiss Project-Number: 99.0218-2