Cancellation properties in Hall magnetohydrodynamics with a strong guide magnetic field.
We present a signed measure analysis of compressible Hall magnetohydrodynamic turbulence with an external guide field. Signed measure analysis allows us to characterize the scaling behavior of the sign-oscillating flow structures and their geometrical properties (fractal dimensions of structures). A reduced numerical model, valid when a strong guide magnetic field is present, is used here. In order to discuss the effect of the Hall term, different values for the ion skin depth are considered in the simulations. Results show that as the Hall term is increased, the fractal dimension of the current and vorticity sheets decreases. This observation, together with previous analysis of the same fields, provides a comprehensive description of the effect of the Hall force on the formation of structures. Two main processes are identified, namely, the widening and unraveling of the sheets.
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Buenos Aires 1428, Argentina.
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Martin
Dipartimento di Fisica, Università degli Studi della Calabria, 87036 Rende, Cosenza, Italy.
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De Vita
CNR, IPCF, UOS di Cosenza, 87036 Rende, Cosenza, Italy and Space Sciences Laboratory, University of California, Berkeley, Berkeley, California 94720, USA.
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Sorriso-Valvo
Departamento de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and IFIBA, CONICET, Buenos Aires 1428, Argentina.
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Dmitruk
Dipartimento di Fisica, Università degli Studi della Calabria, 87036 Rende, Cosenza, Italy.
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Nigro
Dipartimento di Fisica, Università degli Studi della Calabria, 87036 Rende, Cosenza, Italy.
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Primavera
Dipartimento di Fisica, Università degli Studi della Calabria, 87036 Rende, Cosenza, Italy.
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Carbone