Astronomy and Astrophysics – Astrophysics
Scientific paper
Mar 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990ap%26ss.165..153l&link_type=abstract
Astrophysics and Space Science (ISSN 0004-640X), vol. 165, no. 1, March 1990, p. 153-161.
Astronomy and Astrophysics
Astrophysics
10
Earth Ionosphere, Earth Magnetosphere, Extremely Low Radio Frequencies, Magnetohydrodynamic Stability, Magnetohydrodynamic Waves, Polar Cusps, Electric Fields, Ion Acoustic Waves, Ion Beams, Perturbation Theory, S Waves
Scientific paper
The velocity shear of ion beams observed in the polar cusp region can drive the kinetic Alfven modes unstable. A hot ion beam can excite both a resonant kinetic Alfven wave instability and a nonresonant coupled Alfven ion-acoustic wave instability. For the case of a cold ion beam only the latter instability is excited. For the altitude range of 5-7 R(E), velocity shear S of about 0.04-1.0 is needed to excite the kinetic Alfven wave instabilities. The excited modes have frequencies, in the satellite frame of reference, in the ULF frequency range. The noise generated by the velocity shear-driven Alfven modes is electromagnetic in nature. These modes have a substantial component of parallel electric fields and, therefore, they can play an important role in the ionosphere-magnetosphere coupling process occurring in the polar cusp region.
No associations
LandOfFree
Generation of ULF waves in the polar cusp region by velocity shear-driven kinetic Alfven modes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Generation of ULF waves in the polar cusp region by velocity shear-driven kinetic Alfven modes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Generation of ULF waves in the polar cusp region by velocity shear-driven kinetic Alfven modes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1885887