@Article{SahaiFJACKHPGAB:2011:StIoFr,
author = "Sahai, Y. and Fagundes, P. R. and Jesus, R. de and Abreu,
Alessandro Jos{\'e} de and Crowley, G. and Kikuchi, T. and Huang,
C. -S. and Pillat, V. G. and Guarnieri, F. L. and Abalde,
Jos{\'e} Ricardo and Bittencourt, J. A.",
affiliation = "Univ Vale Paraiba UNIVAP, Dept Phys \& Astron, Sao Jose Dos
Campos, SP, Brazil and Department of Physics and Astronomy,
Universidade do Vale do Paraiba (UNIVAP), S{\~a}o Jos{\'e} Dos
Campos, SP, Brazil and Univ Vale Paraiba UNIVAP, Dept Phys \&
Astron, Sao Jose Dos Campos, SP, Brazil and Department of Physics
and Astronomy, Universidade do Vale do Paraiba (UNIVAP), S{\~a}o
Jos{\'e} Dos Campos, SP, Brazil and Atmospheric \& Space
Technology Research Associates (ASTRA) LLC, San Antonio, TX, USA
and STELAB, Nagoya University, Furo-cho, Chikusa-ku, Nagoya
464-8601, Japan and Institute of Scientific Research, Boston
College, Chestnut Hill, MA, USA and Department of Physics and
Astronomy, Universidade do Vale do Paraiba (UNIVAP), S{\~a}o
Jos{\'e} Dos Campos, SP, Brazil and Vale Solu{\c{c}}{\~o}es em
Energia (VSE), S{\~a}o Jos{\'e} dos Campos, SP, Brazil and
Department of Physics and Astronomy, Universidade do Vale do
Paraiba (UNIVAP), S{\~a}o Jos{\'e} Dos Campos, SP, Brazil
2Atmospheric \& Space Technology Research Associates (ASTRA) LLC,
San Antonio, TX, USA and {Instituto Nacional de Pesquisas
Espaciais (INPE)}",
title = "Studies of ionospheric F-region response in the Latin American
sector during the geomagnetic storm of 21-22 January 2005",
journal = "Annales Geophysicae",
year = "2011",
volume = "29",
number = "5",
pages = "919--929",
keywords = "Ionosphere, Ionosphere-magnetosphere interactions,
GENERAL-CIRCULATION MODEL, GPS PHASE FLUCTUATIONS, EQUATORIAL
REGION, LOW LATITUDES, ELECTRODYNAMICS, SIMULATIONS, CONVECTION,
VELOCITIES, MINIMUM, EQUINOX.",
abstract = "In the present investigation, we have studied the response of the
ionospheric F-region in the Latin American sector during the
intense geomagnetic storm of 21-22 January 2005. This geomagnetic
storm has been considered {"}anomalous{"} (minimum Dst reached -
105 nT at 07: 00 UT on 22 January) because the main storm phase
occurred during the northward excursion of the B(z) component of
interplanetary magnetic fields (IMFs). The monthly mean F(10.7)
solar flux for the month of January 2005 was 99.0 sfu. The
F-region parameters observed by ionosondes at Ramey (RAM; 18.5
degrees N, 67.1 degrees W), Puerto Rico, Jicamarca (JIC; 12.0
degrees S, 76.8 degrees W), Peru, Manaus (MAN; 2.9 degrees S, 60.0
degrees W), and Sao Jose dos Campos (SJC; 23.2 degrees S, 45.9
degrees W), Brazil, during 21-22 January (geomagnetically
disturbed) and 25 January (geomagnetically quiet) have been
analyzed. Both JIC and MAN, the equatorial stations, show
unusually rapid uplifting of the F-region peak heights (hpF2/hmF2)
and a decrease in the NmF2 coincident with the time of storm
sudden commencement (SSC). The observed variations in the F-region
ionospheric parameters are compared with the TIMEGCM model run for
21-22 January and the model results show both similarities and
differences from the observed results. Average GPS-TEC (21, 22 and
25 January) and phase fluctuations (21, 22, 25, 26 January)
observed at Belem (BELE; 1.5 degrees S, 48.5 degrees W), Brasilia
(BRAZ; 15.9 degrees S, 47.9 degrees W), Presidente Prudente (UEPP;
22.3 degrees S, 51.4 degrees W), and Porto Alegre (POAL; 30.1
degrees S, 51.1 degrees W), Brazil, are also presented. These GPS
stations belong to the RBMC/IBGE network of Brazil. A few hours
after the onset of the storm, large enhancements in the VTEC and
NmF2 between about 20:00 and 24:00 UT on 21 January were observed
at all the stations. However, the increase in VTEC was greatest at
the near equatorial station (BELE) and enhancements in VTEC
decreased with latitude. It should be pointed out that no phase
fluctuations or spread-F were observed in the Latin American
sector during the post-sunset pre-reversal time in the geomagnetic
disturbance (21 January). The disturbance dynamo electric field
possibly resulted in downward drift of the F-region plasma and
inhibited the formation of spread-F.",
doi = "10.5194/angeo-29-919-2011",
url = "http://dx.doi.org/10.5194/angeo-29-919-2011",
issn = "0992-7689",
label = "self-archiving-INPE-MCTIC-GOV-BR",
language = "en",
targetfile = "angeo-29-919-2011.pdf",
urlaccessdate = "20 maio 2024"
}