VOTALP II: Vertical ozone transports in the alps

• Unité de recherche: PCRD EU
• Numéro de projet: 97.0021-1
• Titre du projet anglais: VOTALP II: Vertical ozone transports in the alps

Mots-clé (Anglais)

Free troposphere/cosmogenic radionuclides/radon/Pb-210

Autre Numéro de projet (Anglais)

EU project number: ENV4-CT97-0413

Programme de recherche (Anglais)

EU-programme: 4. Frame Research Programme - 3.1 Environment

Description succincte (Anglais)

See abstract

Partenaires et organisations internationales (Anglais)

Coordinator: Universität für Bodenkultur Wien (A)

Résumé des résultats (Abstract) (Anglais)

The Be-7 measurements at Jungfraujoch were completed for the four-year period 1996-1999. The average activity concentrations of this cosmogenic radionuclide at this site was found to be 7.25 mBq/m3 , roughly 3.5 times higher compared to data measured by the SUER in the Swiss midlands. This altitudinal effect clearly points to a scavenging effect as the prime cause.

The new data from 1999 corroborate previous observation, that at Jungfraujoch Be-7 activity concentrations exhibit only a weak seasonal fluctuation, with maxima in late summer. This observations may be explained by convective transport in the lower troposphere rather than intrusions from the stratosphere.

In order to perform a quantitative intercomparison of Be-7 measurements from other highalpine stations such as Sonnblick, Zugspitze, and Monte Cimone an additional intercomparison of the detection devices used to measure this nuclides via its 478 keV gamma line was performed. As a result, the four participating laboratories were able to deliver values which did not scatter by more than two standard deviations.

To conclude, VOTALP I and II delivered for the first time a continuous atmospheric record of the short-lived cosmogenic radionuclide Be-7 at the high-alpine station Jungfraujoch. Interpretation of the data set, however, clearly proved that average activity concentrations are not primarily influenced by stratospheric intrusions but more by scavenging effects and transport processes in the troposphere. This may be different for single cases, where indeed
- at least for one case - a high Be-7 activity concentration could be correlated to a tropopause folding in Northern Europe followed by advective transport to the Alps.

Future research will concentrate on Be-7/Be-10 measurements as a possible new tool to quantify stratospheric intrusions. This project has already been approved within the EU-project STACCATO.

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: 97.0021-1