%0 Journal Article
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%3 VHF radar studies.pdf
%X We have analyzed the data collected during an observational campaign of the equatorial electrojet (EEJ) plasma irregularities using 50MHz coherent back-scatter radar operated at Sao Luis, Brazil. The 7-day campaign were characterized by a disturbed 3-day period in the beginning followed by 'quiet' days. A correlative analysis of the auroral electrojet (AE) indices and radar and magnetometer data are carried out to investigate the diverse characteristics of the responses of the EEJ and its instabilities processes to the disturbance zonal electric fields that penetrate to equatorial latitudes during auroral disturbance. Large degrees of day-to-day variability in the EEJ current intensity, 3-m echo powers and spectral features were observed even under absence of any auroral disturbances. Among the outstanding results of this analysis are the following findings: (a) the observed EEJ current and 3-m irregularity response phases to the intensification/decay phases of an auroral sub-storm event agree with the prediction by the existing models; (b) the phase relationship of the EEJ response versus AE intensification is altered/inverted under the presence of a ring current (D-st) development; (c) the amplitude of the EEJ response show clear local time dependence being maximum around noon; and (d) significant increase in the type-1 (two-stream wave) Doppler velocity exceeding the nominal ion-acoustic speed is observed under magnetically disturbed conditions. These results are presented and discussed. (C) 2004 Elsevier Ltd. All rights reserved..
%8 Nov.
%N 17
%T VHF radar studies of the equatorial electrojet 3-m irregularities over Sao Luis: day-to-day variabilities under auroral activity and quiet conditions
%@secondarytype PRE PI
%K equatorial, E-region, equatorial electrojet, VHF coherent scatter radar echoes, plasma instabilities / DISTURBANCE DYNAMO, FIELD, IONOSPHERE, FLUCTUATIONS, PENETRATION, VELOCITY, ORIGIN, WAVES.
%@visibility shown
%@group DAE-INPE-MCT-BR
%@secondarykey INPE-12967-PRE/8246/
%@copyholder SID/SCD
%@issn 1364-6826
%2 sid.inpe.br/iris@1916/2005/08.16.13.34.33
%@affiliation Instituto Nacional de Pesquisas Espaciais, Divisão de Aeronomia  (INPE. DAE)
%B Journal of Atmospheric and Solar-Terrestrial Physics
%P 1603-1613
%4 sid.inpe.br/iris@1916/2005/08.16.13.34
%D 2004
%V 66
%A C, Denardini,
%A Abdu, Mangalathayil Ali,
%A Sobral, Jose Humberto Andrade,
%@dissemination WEBSCI; PORTALCAPES; AGU; MGA; COMPENDEX.
%@area CEA