Accueil > Actualités > Séminaires > Séminaire de Gabriele Stiller au LMD-ENS


Titre : Global stratospheric mean age of air and its temporal variation from MIPAS SF6 observations
Nom du conférencier : Gabriele Stiller
Son affiliation : Institute for Meteorology and Climate Research, Karslruhe Institute of Technology
Laboratoire organisateur : LMD
Date et heure : 29-05-2013 14h30
Lieu : Salle E314 du département de geoscience à l'ENS
Résumé :

The first global stratospheric mean age of air observational data record covering almost 10 years has been derived from monthly zonal means of SF6 measured by MIPAS/Envisat. The 10-years time series of global stratospheric age of air has been analysed regarding its short-term variations (seasonal, semi-annual, QBO), and its decadal behaviour. The derived linear trends were found to be inhomogeneous over the globe, with increasing age of air in Northern mid-latitudes and middle tropics, and decreasing age of air in the tropical lowermost stratosphere and larger parts of the Southern mid-latitudes. The trend pattern will be compared to that of other transport tracers measured by MIPAS. Analysis of the amplitudes and phases of the seasonal variation allows conclusions on the coupling of tratospheric regions to each other. The observational data will be nterpreted in terms of a accelaration/decelaration of the Brewer-Dobson circulation and discussed in context with recent published modelling results.