Intermittency and Avalanching in Turbulent Space Plasmas: from Models to Reality
Vadim M. Uritsky
Institute for Space Research, University of Calgary
I present a new approach for quantifying multiscale intermittency in complex natural systems with spatially extended degrees of freedom, including those commonly studied in solar- and space physics. The approach is based on spatiotemporal decomposition of a continuum time-dependent turbulent field into a set of discrete dissipation events similar to energy avalanches in sandpile models, and its subsequent filtering and analysis. The idea is illustrated by a variety of examples, including flaring activity in the solar corona, electron precipitation dynamics in the auroral zone of Earth's ionosphere, and bursty magnetic energy transport in turbulent MHD simulations. In each case, the proposed method provides significant new information on the scaling regimes, predictability, correlation patterns and the underlying thermodynamic states of the studied systems.
Date: Vendredi, le 26 septembre 2008 Heure: 10:00 Lieu: Université de Montréal Pavillon Roger-Gaudry, Local D-460 Contact: Pierre Bergeron