@InProceedings{ArrudaSobAndAbdMas:2007:EvPrPe,
author = "Arruda, D. and Sobral, Jos\é and Andrade, Humberto and Abdu,
Mangalathayil Ali and Mascarenhas, M.",
affiliation = "{} and {Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)}",
title = "Evidences of prompt penetration and disturbance dynamo electric
field responses in the equatorial and low-latitude ionosphere
during HILDCAA events",
booktitle = "Proceedings...",
year = "2007",
organization = "Latin-American Conference on Space Geophysics, 8. (COLAGE).",
abstract = "This study focuses equatorial and low-latitude ionospheric
responses to High Intensity Long Duration Auroral Electrojet
Activity (HILDCAA) events. Such HILDCAA events, identified by
Tsurutani and Gonzalez (1987), are characterized essentially by a)
intense activities in the auroral zone during the absence of
geomagnetic storm (main phase) and b) high frequency fluctuations
in the north-south component of the interplanetary magnetic field.
Equatorial and low-latitude ionospheric responses in the Brazilian
sector (38o-45oW) are in the F-layer height and critical frequency
modifications obtained from digisondes located at Cachoeira
Paulista (low latitude region: 22.5oS, 45oW) and S{\"O}o Luis
(equatorial region: 2oS, 44oW). Of all HILDCAA events analyzed, 3
events that occurred on 11-14 May, 2001 (peak maximum solar), on
3-7 July and on 20-25 August, 2003 (descending solar cycle)
presented significant modifications as strong presences of prompt
penetrating and disturbance dynamo electric fields that on 3-7
July, 2003 were similar those observed during a typical
geomagnetic storm, and low-latitude F-layer critical frequency
increases attributed to equatorial anomaly expansion and
thermospheric composition. This study is an extension of
HILDCAA/Fast co-rotating beam event effects analyzed by Sobral et
al. (2006) and it intends to contribute to improve theoretical
simulations as well as the knowledge about near-Earth space
weather.",
conference-location = "Merida, Mexico",
conference-year = "11-17 July",
language = "en",
urlaccessdate = "16 jun. 2024"
}