Interplanetary collisionless shock waves.

Thesis (Sc D.)--Massachusetts Institute of Technology, Dept. of Meteorology, 1970.Vita.Bibliography: leaves 148-150.Sc D

On the nature and shape of noctilucent cloud particles

Thesis (M.S.) University of Alaska Fairbanks, 1965The exact theory of the scattering of light from spheres, double-layer spheres, infinite long cylinders and coaxial cylinders is presented here in detail. The theory of scattering from spheres and infinite long cylinders is then applied to the noctilucent Cloud (NCL) problem. The intensity and polarization versus scattering angle, particle size, and wavelength for spherical particle scattering with index of refraction 1.33 (corresponding to ice and stone) were calculated with an IBM 1620 electronic computer and the results are compared with the available experimental data. The experimental data was also compared with the results of Deirmendjian, Clasen, etc., allowing conclusions with regard to the possibility of spherical pure metallic particles. The results indicate that the NLC particles are either stony dust or ice coated stony dust rather than pure metallic in nature. Consideration is given to the possibility of detecting through polarization and spectrographic studies the possible growth of NLC particles resulting from the formation of ice on them. If the NLC become visible only as a result of an increase of the number of particles, then the shape of the polarization versus scattering angle curve will not change, and the intensity versus wavelength curve will not change in shape but only in amplitude. However, if particle growth is responsible for the NLC becoming visible, then the shape of the polarization versus scattering angle curve will change. Careful experimental observations of these quantities should then answer this question about particle growth. A detailed analysis of the NLC particle sampling data obtained in Sweden during 1962 is made. A particle size distribution of the form Nα(diameter)⁻⁴ is required for the sampling data to be consistent with the polarization measurements that have been made

Simulation in the Front Region of the Earth¡¦s Magnetosphere

A laboratory experiment was conducted to investigate the interaction between a plasma beam and a magnetic dipole, simulating the interaction between the solar wind and magnetized planets. The emphasis in this paper is on the laboratory simulation in the front region of the Earth¡¦s magnetosphere and their variation under different solar wind conditions. The boundary in the front region of the magnetosphere is observed in a space simulation laboratory and the magnetospheric structure is produced by a super-Alfvénic and collisionless plasma beam interacting with terrella field. The boundary of the magnetosphere is determined by the factors that include solar wind parameters, such as magnetic fields, ion current density and magnetospheric structure images. It is interesting to compare the results of laboratory simulations with the empirical model by Shue et al. (1997) and the theoretical model by Cheng (1998) as well for the prediction of magnetopause locations under any solar wind condition. The comparisons show that for the northward IMF, magnetopause locations in the laboratory simulation are consistent with the theoretical model. As the magnitude of northward IMF Bz becomes higher, the subsolar distance and the flank position in laboratory simulations are consistent with the empirical model as well. For a lower southward IMF Bz, magnetopause locations in laboratory simulations are consistent with both the empirical and theoretical models. As the magnitude of the southward IMF Bz becomes higher, the subsolar distance and the flank position in laboratory simulations seem closer to the theoretical model than the empirical model