@Article{SahaiFBACPIAPB:2004:LoDiOb,
author = "Sahai, Y. and Fagundes, P. R. and Becker Guedes, F. and Abalde, J.
R. and Crowley, G. and Pi, X. and Igarashi, K. and Amarante, G. M.
and Pimenta, Alexandre Alvares and Bittencourt, Jos{\'e}
Augusto",
affiliation = "{Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and
{Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and
{Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and
{Universidade do Vale do Para{\'{\i}}ba (UNIVAP)} and {Southwest
Research Institute} and {Jet Propulsion Laboratory} and
{Communications Research Laboratory} and {The Abdus Salam (ICTP)}
and Instituto Nacional de Pesquisas Espaciais, Divis{\~a}o de
Aeronomia (INPE.DAE) and Instituto Nacional de Pesquisas
Espaciais, Divis{\~a}o de Aeronomia (INPE.DAE)",
title = "Longitudinal differences observed in the ionospheric F-region
during the major geomagnetic storm of 31 March 2001",
journal = "Annales Geophysicae",
year = "2004",
volume = "22",
number = "9",
pages = "3221--3229",
keywords = "AERONOMY, Ionosphere, Ionospheric disturbances, Modelling and
forecasting, Magnetospheric physics, Storms and substorms,
Atmospheric, Gravity waves, Equatorial ionosphere, Imaging
observations, Plasma depletions, Mangetic storms, Wags campaign,
Disturbances, AERONOMIA, Ionosfera, Dist{\'u}rbios
ionosf{\'e}ricos, F{\'{\i}}sica magnetosf{\'e}rica,
Tempestades, Ondas da gravidade atmosf{\'e}rica, Ionosfera
equatorial, Observa{\c{c}}{\~a}o de imagens, Tempestades
magn{\'e}ticas.",
abstract = "A new ionospheric sounding station using a Canadian Advanced
Digital Ionosonde (CADI) was established for routine measurements
by the {"}Universidade do Vale do Paraiba (UNIVAP){"} at Sao Jose
dos Campos (23.2degrees S, 45.9degrees W), Brazil, in August 2000.
A major geomagnetic storm with gradual commencement at about 01:00
UT was observed or 31 March 2001. In this paper, we present and
discuss salient features from the ionospheric sounding
measurements carried out at S. J. Campos on the three consecutive
UT days 30 March (quiet), 31 March (disturbed) and I April
(recovery) 2001. During most of the storm period. the foF2 values
showed negative phase, whereas during the two storm-time peaks,
large F-region height variations were observed. In order to study
the longitudinal differences observed in the F-realon during the
storm, the simultaneous ionospheric sounding measurements carried
out at S. J. Campos. El Arenosillo (37.1degrees N, 6.7degrees W),
Spain, Okinawa (26.3degrees N, 127.8degrees E), Japan and Wakkanai
(45.5degrees N, 141.7degrees E), Japan, during the period 30
March-1 April 2001, have been analyzed. A comparison of the
observed ionospheric parameters (h'F and foF2) in the two
longitudinal zones (1. Japanese and 2. Brazilian-Spanish) shows
both similarities and differences associated with the geomagnetic
disturbances. Some latitudinal differences are also observed in
the two longitudinal zones. In addition, global ionospheric TEC
maps from the worldwide network of GPS receivers are presented,
showing widespread TEC changes during both the main and recovery
phases of the storm. The ionospheric sounding measurements are
compared with the ASPEN-TIMEGCM model runs appropriate for the
storm conditions. The model results produce better agreement
during the quiet period. During the disturbed period, some of the
observed F-region height variations are well reproduced by the
model results. The model foF2 and TEC results differ considerably
during the recovery period and indicate much stronger negative
phase at all the stations, particularly at the low-latitude
ones.",
copyholder = "SID/SCD",
issn = "0992-7689",
language = "en",
targetfile = "longitudinal differences.pdf",
urlaccessdate = "11 maio 2024"
}