It has been suggested by radio observations of polarized synchrotronemissions that downstream magnetic field in some young supernova remnants areoriented radially. We study magnetic field distribution of turbulent supernovaremnant driven by the Richtmyer-Meshkov instability -- in other words, theeffect of rippled shock -- by using three-dimensional magnetohydrodynamicssimulations. We find that the induced turbulence has radially biasedanisotropic velocity dispersion that leads to a selective amplification of theradial component of the magnetic field. The Richtmyer-Meshkov instability isinduced by the interaction between the shock and upstream density fluctuations.Future high-resolution polarization observations can distinguish the followingcandidates responsible for the upstream density fluctuations: (i) inhomogeneitycaused by the cascade of large-scale turbulence in the ISM so-called thebig-power-law-in-the-sky, (ii) structures generated by the Drury instability inthe cosmic-ray modified shock, and (iii) fluctuations induced by the non-linearfeedback of the cosmic-ray streaming instability.
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