@Article{FejerJenKikAbdCha:2007:EqIoEl,
author = "Fejer, B. G. and Jensen, J. W. and Kikuchi, T. and Abdu,
Mangalathayil Ali and Chau, J. L.",
affiliation = "Center for Atmospheric and Space Science, Utah State University
and Center for Atmospheric and Space Science, Utah State
University and Solar Terrestrial Environment Laboratory, Nagoya
University and {Instituto Nacional de Pesquisas Espaciais (INPE)}
and Radio Observatorio de Jicamarca, Instituto Geofisico del
Peru",
title = "Equatorial ionospheric electric fields during the November 2004
magnetic storm",
journal = "Journal of Geophysical Research",
year = "2007",
volume = "112",
number = "A10",
pages = "A10304 (11pp)",
month = "Oct.",
keywords = "disturbance electric fields, ionospheric storm effects, ionos
plasma drifts.",
abstract = "We use radar measurements from the Jicamarca Radio Observatory,
magnetometer observations from the Pacific sector and ionosonde
data from Brazil to study equatorial ionospheric electric fields
during the November 2004 geomagnetic storm. Our data show very
large eastward and westward daytime electrojet current
perturbations with lifetimes of about an hour (indicative of
undershielding and overshielding prompt penetration electric
fields) in the Pacific equatorial region during the November 7
main phase of the storm, when the southward IMF, the solar wind
and reconnection electric fields, and the polar cap potential
drops had very large and nearly steady values. This result is
inconsistent with the recent suggestion that solar wind electric
fields penetrate without attenuation into the equatorial
ionosphere for several hours during storm main phase. The largest
daytime prompt penetration electric fields (about 3 mV/m) ever
observed over Jicamarca occurred during the November 9 storm main
phase, when large equatorial electrojet current and drift
perturbations were also present in the Pacific and Brazilian
equatorial regions. The rise and decay times of these equatorial
electric fields were about 20 min longer than of the corresponding
solar wind electric fields. The ratios of prompt penetration
electric fields and corresponding solar wind electric field
changes were highly variable even during the day, and had largest
values near dawn. Also, the prompt penetration electric fields did
not show polar cap potential drop saturation effects. Our results
clearly highlight that the relationships of prompt penetration and
solar wind electric fields, and polar cap potentials are far more
complex than implied by simple proportionality factors.",
doi = "10.1029/2007JA012376",
url = "http://dx.doi.org/10.1029/2007JA012376",
issn = "0148-0227 and 2156-2202",
label = "self-archiving-INPE-MCTIC-GOV-BR",
language = "en",
targetfile = "jgra18869.pdf",
urlaccessdate = "20 maio 2024"
}