Hamiltonian reduced gyrofluid models

Emanuele Tassi
Université Cote d’Azur, Observatoire de la Cote d’Azur, CNRS, Laboratoire J.L. Lagrange, Boulevard de l’Observatoire, CS 34229, 06304 Nice Cedex 4, France
Reduced fluid models provide a useful tool for qualitative investigations of low-frequency phenomena in plasmas, in the presence of a strong, mean component of the magnetic field. Applications of such models include, for example, magnetic reconnection and turbulence, both in laboratory and astrophysical plasmas. In particular, when investigating phenomena occurring on scales comparable with the ion Larmor radius, the so called reduced gyrofluid models become especially relevant. In the non-dissipative limit, reduced gyrofluid models are supposed to possess a Hamiltonian structure, as is the case for all dynamical plasma models. In addition to its relevance for guaranteeing correct qualitative properties of the dynamics, the knowledge of the Hamiltonian structure can also be of use, for instance, for the identification of families of invariants, particularly relevant in the two-dimensional limit, or for stability analyses. In this talk I will present a rather general framework for deriving a class of Hamiltonian reduced gyrofluid models accounting for equilibrium temperature anisotropies and magnetic perturbations parallel to the mean magnetic field, which could make such models relevant for applications to space plasmas.