Study of the magnetic turbulence in a corotating interaction region in the interplanetary medium

[摘要] We study the geometry of magneticfluctuations in a CIR observed by Pioneer 10 at 5 AU between days 292 and 295 in1973. We apply the methodology proposed by Bieber et al. to make acomparison of the relative importance of two geometric arrays of vectorpropagation of the magnetic field fluctuations: slab and two-dimensional (2D).We found that inside the studied CIR this model is not applicable due to therestrictions imposed on it. Our results are consistent with Alfvenicfluctuations propagating close to the radial direction, confirmingMavromichalaki et al.'s findings. A mixture of isotropic andmagnetoacoustic waves in the region before the front shock would be consistentwith our results, and a mixture of slab/2D and magnetoacoustic waves in a regionafter the reverse shock. We base the latter conclusions on the theoreticalanalysis made by Kunstmann. We discuss the reasons why the composite model cannot be applied in the CIR studied although the fluctuations inside it are twodimensional.

Key words. Solar physics · astrophysics and astronomy(magnetic fields) · Space plasma physics (turbulence; waves and instabilities)

[学科分类] 地球科学(综合)