A simple oblique dip model for geomagnetic micropulsations

[摘要] It is pointed out that simple models adoptedso far have tended to neglect the obliquity of the magnetic field lines enteringthe Earth's surface. A simple alternative model is presented, in which theambient field lines are straight, but enter wedge shaped boundaries at half aright-angle. The model is illustrated by assuming an axially symmetric,compressional, impulse type disturbance at the outer boundary, all otherboundaries being assumed to be perfectly conducting. The numerical method usedis checked from the instant the excitation ceases, by an analytical method. Thefirst harmonic along field lines is found to be of noticeable size, but appearsto be mainly due to coupling with the fundamental, and with the first harmonicacross field lines.

Key words. Magnetospheric physics (MHD waves andinstabilities).

[学科分类] 地球科学(综合)