Correlated Wave and Particle Observations Upstream of the Earth's Bow Shock

摘要

Data from three International Sun Earth Explorer experiments during several periods of turbulence observed in the solar wind upstream of the Earth's quasi parallel bow shock were analyzed. Radio observations are used to validate a shock model, used to compute various geometrical parameters for the periods studied. It is shown that the radio noise spectrum has two components, one centered around the local electron plasma frequency and the other at somewhat lower frequencies. The latter component has a shorter wavelength and correlates with the level of (MHD) magnetohydrodynamic turbulence. A multivariate canonical analysis of particle and MHD data shows that the proton anisotropy and turbulence level correlate well with the minimum backstreaming proton parallel velocity. Trivariate analysis shows that the correlation of particles and turbulence with the angle between the magnetic field and the shock normal have their sense reversed. Good correlation is found between power and compressibility in magnetic fluctuations.