Date of Award
Program or Major
Doctor of Philosophy
Martin A Lee
In Part I we present a revised version of the self-consistent theory of ion diffusive shock acceleration and associated generation of hydromagnetic waves at a planar stationary shock. Coupled wave kinetic and energetic particle transport equations are solved numerically and compared with an analytical approximation similar to that derived by Lee [1982, 1983]. The analytical approximation provides an accurate representation of both the proton distribution and the wave intensity. Excellent agreement between the predicted wave magnetic power spectral density adjacent to the shock as a function of frequency and the wave spectrum measured by ISEE 3 at the November 11--12, 1978, interplanetary traveling shock is achieved. A comparison is also made between the predicted total wave energy density and that observed upstream of Earth's bow shock by the AMPTE/IRM satellite for a statistical study of approximately 400 near-to-nose events from late 1984 and 1985. The correlation between the observed wave power and the prediction is very good with a correlation coefficient of 0.92. However, the average observed wave magnetic energy density is approximately 63% of that predicted, suggesting possible wave dissipation, which is not included in the theory.
In Part II we present a semi-analytical solution of the gyrophase-averaged ion transport equation for ion distribution functions in the extended corona. We adopt the essential features of the kinetic shell model [Isenberg , 1997; 2001a, b, c; Isenberg et al., 2000, 2001] and thus, we describe the ion distribution as comprised of cyclotron-resonant and nonresonant parts. We include gravity, the ambipolar electric field, adiabatic deceleration, and magnetic mirroring, but keep the solar wind and wave phase speeds constant. The cold, electron-proton plasma dispersion relation is used to determine the wave-ion resonance condition. The actual, analytical forms of the ion distribution functions obtained are clearly not Maxwellian or bi-Maxwellian. Our solutions describe some of the non-thermal phenomena frequently observed in the extended corona: anisotropic temperature distributions, and differential streaming between protons and minor ion species. However, we fail to model the observed radial temperature dependence of protons and O5+ ions.
Gordon, Bruce Edward, "Resonant wave-ion interactions in the heliosphere: I. Interplanetary traveling shocks, II. Ion heating and acceleration in the extended corona" (2002). Doctoral Dissertations. 103.