Accueil > Actualités > Séminaires > Séminaire de Paul KONOPKA


Titre : Asian monsoon - an important pathway into the stratosphere
Nom du conférencier : Paul KONOPKA
Son affiliation : Institute for Energy and Climate Research - Stratosphere (IEK-7) Forschungszentrum Juelich, D-52425 Germany
Laboratoire organisateur : LMD
Date et heure : 08-11-2013 14h00
Lieu : ENS, 24 rue Lhomond, Paris - Salle 314
Résumé :

The great population growth in Southeast Asia and the accompanying rapid economic growth cause increasing regional and global pollution of the atmosphere. The Asian summer monsoon in particular constitutes a persistent circulation pattern transporting climate-relevant emissions from the surface boundary layer to the lower stratosphere. The Asian monsoon forms a high-pressure area at an altitude of approx. 10-18 km that is almost stationary for three months and covers almost all of Asia in the form of an anticyclone. This anticyclone, with its core located at approx. 30°N, very effectively traps emissions from Asia transported to this altitude by strong convection current, particularly above India, southern China and Indonesia. As a direct consequence, elevated levels of tropospheric trace gases sush as water vapour, CO and HCN can be found in the anticyclone as well as reduced amounts of stratospheric trace gases such as ozone or HCl. This finding, which has been the subject of much discussion in the last few years, was derived mainly from satellite observation data. However, the extent to which emissions from Asia influence the ocmpositon of the tropical tropopause layer (TTL) is still uncertain. The TTL is a region of the atmosphere stretching across the equator which has a decisive impact on mass transport into the stratosphere and is therefore referred to as the "gateway to the stratosphere". The presentation discusses the methods of modelling such processes as sell as gives the current state of knowledge about this topic.