Dayside long-period magnetospheric pulsations: Solar wind dependence

Journal Article · Mon Feb 01 04:00:00 EST 1988 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA093iA02p00877· OSTI ID:5378041

Junginger, H; Baumjohann, W

The spectral power and occurrence rate of long-period magnetospheric pulsations (predominantly fundamental mode toroidal Pc 5) observed by the electron beam experiment on board GEOS 2 are compared with IMF and solar wind parameters. No clear influences of IMF orientation and magnitude on pulsation amplitudes and occurrence rate are found. Significant correlations, however, do exist between the spectral power of pulsations and the solar wind bulk velocity, and between the spectral power and the solar wind kinetic energy flux. The sign of the latter correlation depends on the Kp index. For Kp = 0 the pulsation power decreases with increasing solar wind kinetic energy flux, whereas it increases for Kpgreater than or equal to1. Our results are consistent with the Kelvin-Helmholtz instability at the inner side of the low-latitude boundary layer being the dominant mechanism for the generation of fundamental mode toroidal Pc 5 magnetospheric pulsations. Flux transfer events play only an inferior role as energy sources for these pulsations. The coupling efficiency of surface waves at the boundary layer to shear Alfven waves near geostationary orbit seems to change significantly if the geostationary orbit is inside the plasmasphere. copyright American Geophysical Union 1988

• Research Organization: Institut fuer Angewandte Geodaesie, Satellitenbeobachtungsstation Wettzell Koetzting, Federal Republic of Germany
• OSTI ID: 5378041
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 93:A2; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALFVEN WAVES
BOUNDARY LAYERS
CORRELATIONS
DAILY VARIATIONS
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC FIELDS
ENERGY SPECTRA
HELMHOLTZ INSTABILITY
HYDROMAGNETIC WAVES
INSTABILITY
INTERPLANETARY MAGNETIC FIELDS
LAYERS
MAGNETIC FIELDS
PLASMA INSTABILITY
PLASMA MACROINSTABILITIES
PLASMA WAVES
PULSATIONS
SOLAR ACTIVITY
SOLAR WIND
SPECTRA
VARIATIONS