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Transmission of solar wind hydromagnetic energy into the terrestrial magnetosphere
Author(s) -
Slawinski R.,
Venkatesan D.,
Wolfe A.,
Lanzerotti L. J.,
Maclennan C. G.
Publication year - 1988
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/gl015i011p01275
Subject(s) - magnetopause , physics , magnetosphere , solar wind , geophysics , interplanetary magnetic field , ionosphere , computational physics , ring current , astrophysics , magnetic field , quantum mechanics
The relationships of hydromagnetic energy in the band ∼20‐50 mHz, as measured on the ground near a dayside magnetopause field line, to the magnitude of the interplanetary magnetic field (IMF) are examined. While previous investigations of high latitude hydromagnetic waves have focused on a few selected events, this letter reports the results of a statistical study of a large sample of data. Specifically, the present study examines previously reported linear relationships between the physical quantities. When a certain selection criterion is imposed, the distribution of signal frequencies ƒ as a function of IMF magnitude B T has two distinct branches for ƒ∼20‐50 mHz. One branch has ƒ independent of B T while the other has ƒ as a linear function of B T similar to the result of Gul'elmi [1974] from a study based upon lower latitude data and more qualitative, visual criteria. It is suggested that this second branch is probably produced by an upstream wave source, most likely the direct transmission of interplanetary ion cyclotron waves into the terrestrial magnetosphere. The branch independent of B T can have a variety of sources, including surface wave excitation on the magnetopause, waves produced by flux transfer events, and ionospheric processes.