
Ionospheric responses to the October 2003 superstorm: Longitude/local time effects over equatorial low and middle latitudes
Author(s) -
Abdu Mangalathayil A.,
Maruyama Takashi,
Batista Inez S.,
Saito Susumo,
Nakamura Maho
Publication year - 2007
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 - 10.1029/2006ja012228
Subject(s) - longitude , ionosphere , equatorial electrojet , electrojet , geology , latitude , ionosonde , daytime , climatology , storm , geomagnetic storm , dynamo , geophysics , atmospheric sciences , geodesy , earth's magnetic field , oceanography , physics , plasma , magnetic field , electron density , quantum mechanics
Ionospheric responses to the major magnetic storm disturbances of October 2003 are investigated using database selected in the Brazilian and Japanese‐Asian longitude sectors. Data obtained from latitudinally spaced digisondes in the equatorial and low‐latitude sites in Brazil and from the Asian and Japanese ionosonde network, the total electron content data from the extensive Japanese GPS receiver chain, and magnetometer data from the Pacific equatorial electrojet stations are analyzed during the period 28–31 October. Prompt penetrating (PP) dawn‐dusk polar cap electric fields produce large F region plasma uplift on the dayside and eveningside, while the associated westward electric field on the nightside produces large downdraft of the F region plasma, and causes development of westward electrojet current, observed for the first time. Episodes of PP electric field effects appear to be of larger intensity over Brazil than over Asian longitudes. Equatorial anomaly, development due to undershielding as well as overshielding electric fields, was observed in the Brazilian and in the Asian sectors. Disturbance dynamo electric field causes large nighttime F layer uplifts that are modulated by strong meridional winds in both sectors. The disturbance electric field local time variation patterns are compared with the results of recent global model (MTIEGCM) simulation by Richmond et al. (2003) and validated in some cases. Transients of transequatorial winds, flipping direction from southward to northward, in the widely separated longitude sectors, were diagnosed to be present toward the final recovery phase of the storm. These results are presented and discussed in this paper.