Hybrid simulations of the magnetosheath compression: Marginal stability path

0176490 - UFA-U 20033537 RIV US eng J - Článek v odborném periodiku
Hellinger, Petr - Trávníček, Pavel - Mangeney, A. - Grappin, R.
Hybrid simulations of the magnetosheath compression: Marginal stability path.
Geophysical Research Letters. Roč. 30, č. 18 (2003), s. 13-1-13-4. ISSN 0094-8276. E-ISSN 1944-8007
Grant CEP: GA AV ČR IAB3042106
Grant ostatní: CNRS(FR) PICS 1175
Výzkumný záměr: CEZ:AV0Z3042911
Klíčová slova: magnetosheath compression * marginal stability path * hybrid simulations
Kód oboru RIV: DG - Vědy o atmosféře, meteorologie
Impakt faktor: 2.422, rok: 2003

This paper reports a two-dimensional hybrid simulation study which utilizes an expanding box model to represent the slow compression of the plasma as it flows through the magnetosheath. In the code we model the compression as an external force: Physical sizes of the simulation box decrease with the time. We present results of a simulation which starts in a parameter region of low beta where the plasma is stable with respect to both the Alfvén ion cyclotron (AIC) and mirror instabilities. In this stable region the plasma behaves double-adiabatically and important proton temperature anisotropy appears. When the plasma become unstable to AIC instability the adiabatic behavior is broken and the AIC waves keep the system close the marginal stability, the theoretical growth rate is about constant and is small and positive. The AIC waves are continuously generated and the proton parallel beta increases with time. This marginal stability behavior is slightly disrupted for high proton parallel beta, where the mirror mode become unstable. The mirror waves rapidly grow and coexist with AIC wave, in later times the growth of AIC waves is inhibited and mirror wave become dominant. During the stages dominated by AIC and mirror waves the anticorrelation between anisotropy and proton parallel beta is observed. The hybrid expanding box simulation directly verifies the marginal stability evolution of the magnetosheath plasma.
Trvalý link: http://hdl.handle.net/11104/0073466