Accueil > Actualités > Séminaires > Angelo VULPIANI au LMD-ENS


Titre : On the Fluctuation-Response Relation in Geophysical Systems
Nom du conférencier : Angelo Vulpiani
Son affiliation : Département de Physique, Université de Rome 'La Sapienza'
Laboratoire organisateur : LMD
Date et heure : 09-06-2011 11h00
Lieu : LMD-ENS, Salle E314, 24 rue Lhomond, 75005
Résumé :

One of the major issues concerning the study of a dynamical system is the response to perturbations. In climate dynamics, for example, it is of major interest to understand how a given variable, e.g., the temperature, is sensitive to alterations of some other component of the system, e.g., the greenhouse gas concentration.

We review the connection between equilibrium and non-equilibrium properties, also known as Fluctuation-Relaxation Relation, and its main aspects in chaotic and turbulent systems. We consider, in particular,the effects of the fast variables on the slow variables in a multiscale system, as far as the sensitivity properties are concerned.

Two examples about (widely speaking) climate modelling are discussed: the Lorenz-96 model and the double-potential well model. Both of them, despite their apparent simplicity, hide the same kind of interesting features of much more complex systems.

Contact :

Riwal Plougonven
Laboratoire de Météorologie Dynamique
Ecole Normale Supérieure
24 rue Lhomond
75231 Paris Cedex 05, France
tel. (+33) 1 44 32 27 31