Accueil Imprimer Annuaire Plan du site Crédits Fil RSS du site Twitter Plans d'accès Contacts Annuaire Webmail Intranet Logo

Accueil > Séminaires et conférences > Séminaires, soutenances de thèses et HDR précédents > 2015 > Séminaires 2015 > Le mercredi 18 mars à 11h

Le mercredi 18 mars à 11h

Anna Tenerani (UCLA, USA)

Fundamental Problems in Understanding the Origins of the Heliosphere

Lieu : Jussieu, salle de reunion du LPP-LERMA, Tour 24-34, 5eme etage

Résumé :
The Sun’s influence extends throughout the solar system via the high temperature corona and its extension into interplanetary space, the heliosphere. The origin of stellar coronae, winds, and, more generally, the ubiquitous existence in the universe of hot plasmas (million degree or more) remains one of the fundamental challenges of astrophysics.
There is overwhelming evidence that solar magnetic fields play a crucial role in heating the corona by providing a vehicle for both energy transport and dissipation, via the development of turbulent cascade, and for energy storage and release, via “fast” magnetic reconnection.
I will address these issues that I have been working on recently, by describing : 1) the effects of solar wind expansion on wave propagation and turbulence, introducing a viable approach to modeling the problem numerically (the Accelerating Expanding Box model), and 2)
recent progress on the triggering and development of fast (i.e. developing on ideal MHD time-scales) magnetic reconnection, including the role of current sheet aspect ratio in triggering plasma instabilities, the role of viscosity, and how kinetic effects intervene.

Tutelles : CNRS Ecole Polytechnique Sorbonne Université Université Paris Sud Observatoire de Paris Convention : CEA
©2009-2019 Laboratoire de Physique des Plasmas (LPP)

Mentions légales
Exploitant du site : Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay F-91128 PALAISEAU CEDEX
Hébergeur : Laboratoire de Physique des Plasmas, Ecole Polytechnique route de Saclay F-91128 PALAISEAU CEDEX
Directeur de la publication : Pascal Chabert (Directeur)