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Propagation of perturbation energy fluxes in the subsolar magnetosheath: AMPTE IRM observations
Author(s) -
Lin N.,
Engebretson M. J.,
Baumjohann W.,
Luehr H.
Publication year - 1991
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 - 10.1029/91gl01849
Subject(s) - magnetosheath , physics , poynting vector , magnetosphere , magnetopause , energy flux , flux (metallurgy) , kinetic energy , poynting's theorem , geophysics , computational physics , perturbation (astronomy) , magnetic flux , magnetic field , atmospheric sciences , classical mechanics , astronomy , materials science , quantum mechanics , metallurgy
We have studied the propagation properties of perturbation energy fluxes of subsolar magnetosheath fluctuations. The Poynting flux, kinetic energy flux, and enthalpy flux are calculated using magnetic field and plasma measurements from the AMPTE IRM satellite during five intervals in 1984. The results are then compared with a disturbance indicator R of the magnetic field in the same magnetosheath region. It is shown that during disturbed periods with large transverse variations (low R level), the perturbation Poynting flux and the kinetic energy flux increase, and a significant portion of the fluxes consistently propagates toward the magnetopause. The Poynting flux of those fluctuations which consist of mainly compressional perturbations does not appear to propagate in any certain direction. The enthalpy flux of the perturbations does not propagate in any certain direction in any of the cases. The kinetic energy flux appears to be more important in exciting harmonic ULF waves in the dayside magnetosphere. What portion of this energy flux is transferred into the magnetosphere needs further investigation.