Open AccessMagnetic impulse events and related Pc1 bursts observed by the Automatic Geophysical Observatories network in Antarctica
Author(s) -
Sato Mitsuteru,
Fukunishi Hiroshi,
Lanzerotti Louis J.,
Maclennan Carol G.
Publication year - 1999
Publication title -
journal of geophysical research: space physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999ja900111
Subject(s) - geology , geophysics , latitude , earth's magnetic field , magnetosphere , fluxgate compass , longitude , ionosphere , magnetometer , geomagnetic latitude , local time , magnetic field , geodesy , physics , statistics , mathematics , quantum mechanics
Magnetic field data obtained by fluxgate and search coil magnetometers installed at four Automatic Geophysical Observatories (AGO Pl, P2, P3, and P4) and at South Pole and McMurdo in Antarctica and at Iqaluit on Baffin Island are used to study the relationship between magnetic impulse events (MIEs) and Pc1 bursts at high geomagnetic latitudes. The spatial scale sizes of MIEs are determined in the investigation of the sources of these events in the magnetosphere. Four MIE events with simultaneous Pc1 bursts are studied. Contour plots of MIE amplitudes show the scale sizes of the examined MIEs to be 5° to 7° in the magnetic latitude direction and 40° to 60° in the magnetic longitude direction. Temporal changes of the ionospheric currents calculated from the fluxgate H‐ and D‐component data indicate that the “convection vortices” associated with the MIEs traveled westward and decayed rapidly. An important finding is that MIE‐related Pc1 bursts were observed at higher‐latitude (Pl, P4 near 80°) and lower‐latitude (P2, P3 near 70°) AGO stations and South Pole Station at 74° with different spectral structures, although the Pc1 spectral power was always a maximum at South Pole Station. These results imply that Pc1 bursts are excited not only in the dayside outer magnetosphere but also in the low‐latitude boundary layer region.