Open AccessField-aligned structure of poloidal Alfvén waves in a finite pressure plasma
Author(s) -
P. N. Mager,
D. Yu. Klimushkin,
В. А. Пилипенко,
Stefan Schäfer
Publication year - 2009
Publication title -
annales geophysicae
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.522
H-Index - 93
eISSN - 1432-0576
pISSN - 0992-7689
DOI - 10.5194/angeo-27-3875-2009
Subject(s) - physics , ionosphere , alfvén wave , field line , plasma , magnetic field , computational physics , equator , geophysics , plasma sheet , mechanics , classical mechanics , magnetosphere , magnetohydrodynamics , latitude , quantum mechanics , astronomy
This paper is devoted to analytical and numerical studies of the parallelstructure of poloidal Alfvén waves in a finite pressure plasma. The effectsof finite-beta plasma are especially essential near the magnetosphericequator, where an opaque (non-transparent) region for Alfvén waves can beformed. This region is bounded by two turning points which restrainpenetration of the wave energy far from the ionosphere, and an Alfvénresonator appears on a part of the field line adjacent to the ionosphere. Dueto this effect the ULF pulsations in the Northern and Southern Hemispherescan be non-conjugated. Another result is a peculiar field-aligned structureof the wave magnetic field: its fundamental harmonic must have three nodes,rather than one node as is the case in cold plasma