Time asymmetry of magnetic field variations in dynamo models

Abstract

We considered two types of magnetic field time asymmetry related to the inverse influence of the magnetic field on the currents in the dynamo models and observations. The first type includes variations in which the total time that the time derivative is positive is different from the time that this derivative is negative. In a monochromatic wave, this corresponds to a failure of symmetry with respect to the point at which the wave has an extremum. The second class includes the time signals at which another failure of antisymmetry appears relative to the mean value of the signal. None of these types of symmetry can be recorded by the methods of the Fourier or wavelet analysis. We use the Parker’s dynamo model in a thin layer and a threedimensional model in a flat rotating layer when heated from below and present estimates of the failure of the symmetry data. It was shown that in the paleo-variations the model time of field increase is smaller than the time of its decrease.