Anisotropy and Symmetry of Fluctuations in the Solar Wind Magnetic Field and Velocity

Erofeev D.V.

Geomagnetism and Aeronomy, Vol. 52, No. 8, 1097–1106 (2012)

DOI: 10.1134/S0016793212080099

Ключевые слова: Solar Wind, Solar Activity, Solar Cycle, Local Magnetic Field, Solar Wind Parameter

Аннотация

The behavior of correlation tensors of fluctuations in the solar wind magnetic field and velocity is studied during different phases of a solar cycle on the basis of a 45-year measurement series of solar wind parameters. It is found that the orientation of fluctuations in the magnetic field and velocity is approximately axisymmetric relative to the direction of a local magnetic field during high solar activity. This symmetry is violated significantly during periods of low solar activity, and deviations from the symmetry are regular and oppositely directed during minima of even and odd 11-year cycles, which is probably connected with variations in the orientation of the Sun’s magnetic field. The dependence of the power of fluctuations on the local magnetic field direction reveals significant deviations from local symmetry during all phases of a solar cycle, especially for velocity fluctuations.