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Geomagnetic conjugate observations of medium‐scale traveling ionospheric disturbances at midlatitude using all‐sky airglow imagers
Author(s) -
Otsuka Y.,
Shiokawa K.,
Ogawa T.,
Wilkinson P.
Publication year - 2004
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 - 10.1029/2004gl020262
Subject(s) - airglow , earth's magnetic field , ionosphere , conjugate points , middle latitudes , sky , magnetic dip , geophysics , geology , geodesy , physics , magnetic field , atmospheric sciences , astrophysics , geometry , mathematics , quantum mechanics
We report for the first time simultaneous observations of medium‐scale traveling ionospheric disturbances (MSTIDs) at geomagnetic conjugate points in both hemispheres, using two all‐sky airglow imagers at midlatitudes. A 630‐nm all‐sky CCD imager at Sata, Japan, detected MSTIDs with a wavefront elongated from NW to SE on the night of August 9, 2002. During this event, MSTIDs with a wavefront elongated from SW to NE were observed at the geomagnetic conjugate point, Darwin, Australia. To investigate geomagnetic conjugacy of the MSTID structures, the Darwin images were mapped The MSTID structures mapped from Darwin to its magnetic conjugate points along the geomagnetic field lines ( B ) coincide closely with those in the Sata images. This result suggests that polarization electric field ( E p ) plays an important role in the generation of MSTIDs. E p maps along B and moves the F region plasma upward or downward by E × B drifts, causing plasma density perturbations with structures mirrored in the northern and southern hemispheres.