Accueil > Actualités > Séminaires > Séminaire de Dale DURRAN au LMD-ENS


Titre : Stratospheric-Tropospheric Exchange and the Mesoscale Dynamics of Thin Tropical Tropopause Cirrus
Nom du conférencier : Dale DURRAN
Son affiliation : Department of Atmospheric Sciences, University of Washington, Seattle, U.S.A.
Laboratoire organisateur : LMD
Date et heure : 31-05-2011 14h30
Lieu : LMD-ENS, Salle E314, Departement des Géosciences, 24 rue Lhomond, 75005
Résumé :

Subvisible cirrus clouds (SVC) occur very frequently in the tropical tropopause layer (TTL), where they play an important role in regulating the stratospheric water-vapor budget. SVC are warmed through the absorption of infrared radiation. The response of the cloud and the surrounding atmosphere to this thermal forcing plays a key role in extending the lifetime of SVC and in increasing the rate at which moist layers in the TTL are dehydrated.
This seminar will explore the mesoscale dynamics of SVC, beginning with an idealized linear model and progressing through a series of increasingly realistic numerical simulations, culminating in a simulation in which the homogeneous nucleation of SVC is triggered in a moist region by large-scale Kelvin waves and the processing of cloud ice by SVC is followed over an several-day life cycle.

Contact :

Riwal Plougonven, LMD-ENS, 01 44 32 27 31