Ground based measurements of atmospheric water vapour profiles

• Unité de recherche: COST
• Numéro de projet: C02.0059
• Titre du projet anglais: Ground based measurements of atmospheric water vapour profiles

Mots-clé (Anglais)

water vapor; stratosphere; global change; microwave; remote sensing

Programme de recherche (Anglais)

COST-Action 723 - The Role of the Upper Troposhere and Lower Stratosphere in Global Change

Description succincte (Anglais)

See abstract

Partenaires et organisations internationales (Anglais)

BE, BG, CH, CY, CZ, DE, DK, ES, FI, FR, GR, IT, NL, NO, PL, PT, SE, UK

Résumé des résultats (Abstract) (Anglais)

The main objective of the Action was to advance the understanding of the state of the global upper troposphere and lower stratosphere, and the role of the dynamical, chemical, and radiative processes in this altitude region, in order to provide an improved basis for policy advice in connection with global change. The above objectives can be addressed by considering the three areas of observations, data analysis, and understanding. The main issue for the Swiss contribution was to participate in the field ob observations with a special emphasis on humidity i.e. water vapour information. Water vapour, the most important greenhouse gas, is an atmospheric constituent of fundamental importance for climate. It also plays many roles in stratospheric chemistry and dynamics. However, very little is known about its actual distribution above the lower and mid troposphere where it is observed by meteorological balloon sondes on a regular basis. Especially in the climate-relevant upper troposphere/lower stratosphere (UT/LS) region that is targeted by COST action 723, measurements of the water vapour distribution are very sparse. Long term observations hardly exist at all, even though a trend in stratospheric water vapour has been established over the last few years that might be related to global change. The main idea of this project was to establish a ground based station that can provide altitude profiles of atmospheric water vapour from the ground to the mesosphere on a routine basis. Since no single measurement technique can cover this large altitude range, several techniques have to be employed at the same location to provide a complete profile. Though the original idea was to combine several techniques of humidity measurements this could not achieved in full detail due to lack of funding. However due to the boost of the COST project other Swiss projects have been strengthened. The highlight certainly is the realization of a new observatory for atmospheric humidity observations of the Institute of Applied Physics at Zimmerwald funded by the canton of Bern and the availability of data through the so called STARTWAVE database of NCCR-climate.

Références bases de données (Anglais)

Swiss Database: COST-DB of the State Secretariat for Education and Research Hallwylstrasse 4 CH-3003 Berne, Switzerland Tel. [phone] Swiss Project-Number: C02.0059