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Pi2 magnetic pulsations as response on spatio‐temporal oscillations of auroral arc current system
Author(s) -
Solovyev S. I.,
Baishev D. G.,
Barkova E. S.,
Molochushkin N. E.,
Yumoto K.
Publication year - 2000
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 - 10.1029/2000gl000037
Subject(s) - substorm , physics , amplitude , luminosity , latitude , arc (geometry) , astrophysics , wavelength , polarization (electrochemistry) , geophysics , middle latitudes , magnetic field , magnetosphere , atmospheric sciences , astronomy , optics , chemistry , geometry , mathematics , quantum mechanics , galaxy
Pi2 magnetic pulsations in the period range from 40 to 150 s are excited both at the magnetospheric substorm onset and during pseudobreakups. Using observations at the 190–210° MM we study the association between the characteristics of high‐latitude Pi2 pulsations and parameters of wave‐like and vortex auroral structures of 50–200 km scale in the brightening auroral arc during short‐term (∼5–10 min) activations. We found that the maximum Pi2 amplitude is observed at the same latitude where the auroral arc is located. The period of high‐latitude Pi2 pulsations is found to be consistent with the ratio of the luminosity wavelength to their propagation velocity and/or coincides with the lifetime of luminosity bright spots. The Pi2 polarization patterns are defined by the direction of luminosity bright spot rotation. These findings indicate that high‐latitude Pi2 pulsations are the response of spatio‐temporal current system oscillations of the auroral arc.