@PhDThesis{Cardoso:2011:AuElPr,
author = "Cardoso, Flavia Reis",
title = "Auroral electron precipitating energy during magnetic storms with
peculiar long recovery phase features",
school = "Instituto Nacional de Pesquisas Espaciais",
year = "2011",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2010-11-29",
keywords = "aurora, estimativa de deposi{\c{c}}{\~a}o de energia auroral,
precipita{\c{c}}{\~a}o de part{\'{\i}}culas, HILDCAA,
tempestades magn{\'e}ticas, auroral energy estimate, particle
precipitation, HILDCAA, aurora,magnetic storms.",
abstract = "Aurora, emiss{\~o}es geradas por colis{\~o}es entre
el{\'e}trons energ{\'e}ticos e part{\'{\i}}culas
atmosf{\'e}ricas, {\'e} frequentemente observada na regi{\~a}o
polar. Embora muito se sabe sobre a aurora, ainda existem
in{\'u}meras quest{\~o}es sem respostas. Por exemplo, n{\~a}o
se conhece qual a fonte das part{\'{\i}}culas energ{\'e}ticas
ou por quais processos tais part{\'{\i}}culas s{\~a}o
energizadas. A compreens{\~a}o do comportamento da aurora {\'e}
um problema cient{\'{\i}}fico importante porque prov{\^e}
informa{\c{c}}{\~a}o sobre os processos que ocorrem durante a
intera{\c{c}}{\~a}o vento solar-magnetosfera. A zona auroral
{\'e} significantemente afetada por tempestades magn{\'e}ticas e
subtempestades. Ocasionalmente, tempestades magn{\'e}ticas exibem
fase de recupera{\c{c}}{\~a}o longa que pode perdurar por
v{\'a}rios dias. Durante tais eventos, os eletrojatos aurorais
podem apresentar atividade de longa dura{\c{c}}{\~a}o e alta
intensidade. Esses eventos s{\~a}o conhecidos como eventos
HILDCAA (\textit{High Intensity Long Duration Continuous AE
Activity}). A pot{\^e}ncia injetada na magnetosfera/ionosfera,
carregada por precipita{\c{c}}{\~a}o de el{\'e}trons, {\'e} um
importante par{\^a}metro que pode ser estimado pelo instrumento
\textit{Ultraviolet Imager} (UVI) a bordo do sat{\'e}lite Polar.
Esse instrumento monitora a morfologia espacial e a
evolu{\c{c}}{\~a}o temporal da aurora na faixa do ultravioleta
distante em ambas condi{\c{c}}{\~o}es de luz e escurid{\~a}o.
Aplicando as corre{\c{c}}{\~o}es necess{\'a}rias ao instrumento
e a remo{\c{c}}{\~a}o de \textit{dayglow}, {\'e}
poss{\'{\i}}vel calcular a energia que chega {\`a} zona
auroral. Nosso objetivo {\'e} obter informa{\c{c}}{\~a}o
quantitativa sobre a fonte de energia de tempestades
magn{\'e}ticas com longa (LRP) e curta (SRP) fase de
recupera{\c{c}}{\~a}o, estimando a quantidade de energia de
precipita{\c{c}}{\~a}o depositada. A energia de
precipita{\c{c}}{\~a}o foi encontrada altamente vari{\'a}vel
para eventos LRP. Uma significante entrada de energia durante
longas fases de recupera{\c{c}}{\~a}o de tempestades
magn{\'e}ticas implica em fonte de energia adicional para manter
a atividade magn{\'e}tica no eletrojato auroral, o qual
acredita-se estar relacionado com flutua{\c{c}}{\~o}es de
velocidade e do campo magn{\'e}tico do vento solar. Por outro
lado, o campo magn{\'e}tico interplanet{\'a}rio IMF permaneceu
na dire{\c{c}}{\~a}o sul por algum tempo em eventos SRP. Todos
os resultados sugerem que os eventos LRP poderiam ser uma
consequ{\^e}ncia de um sistema conduzido pelo vento solar e os
eventos SRP seriam associados a processos de descarregamento de
energia. ABSTRACT: Aurora, light emissions generated by collisions
between energetic electrons and atmospheric particles, is often
seen in the polar region. Although much is known about the aurora,
there are still many questions unanswered. For example, it is not
well known what is the source of the energetic particles or by
what processes the particles are energized. Understanding the
behavior of the aurora is an important scientific problem because
it provides information about the processes occurring during the
solar wind-magnetosphere interaction. The auroral zone is
significantly affected by magnetic storms and substorms.
Occasionally, magnetic storms exhibit a long recovery phase which
can last for several days. During such events, the auroral
electrojet can display high-intensity, long duration activity.
These events are known as HILDCAA events (High Intensity Long
Duration Continuous AE Activity). The power input to the
magnetosphere/ionosphere carried by precipitating electrons is an
important parameter which can be estimated by the Ultraviolet
Imager (UVI) on board the Polar satellite. This instrument
monitors the spatial morphology and temporal evolution of the
aurora in the far ultraviolet range in both sunlight and darkness.
Applying the necessary instrument corrections and the dayglow
removal, it is possible to evaluate the energy coming into the
auroral zone. Our goal is to obtain quantitative information about
the energy source for magnetic storms with long (LRP) and short
(SRP) recovery phases by estimating the amount of precipitation
energy input. Precipitation energy has been found highly variable
for LRP. A significant energy input during long storm recovery
phases implies additional energy source to maintain the magnetic
activity in the auroral electrojet which is believed to be related
to the fluctuating solar wind magnetic field and velocity. On the
other hand, IMF (interplanetary magnetic field) remained southward
for a while in SRP events. All the results suggest LRP could be a
consequence of a solar wind driven system and SRP would be
associated to an energy unloading process.",
committee = "Souza, Jonas Rodrigues de (presidente) and Alves, Maria
Virg{\'{\i}}nia (orientador) and Guarnieri, Fernando
Luiz(orientador) and Echer, Ezequiel and Dallaqua, Renato
S{\'e}rgio and Fillingim, Matthew O. and Ziebell, Luiz Fernando",
copyholder = "SID/SCD",
englishtitle = "Energia de precipita{\c{c}}{\~a}o auroral de el{\'e}trons
durante tempestades magn{\'e}ticas com caracter{\'{\i}}sticas
peculiares de longa fase de recupera{\c{c}}{\~a}o",
language = "en",
pages = "147",
ibi = "8JMKD3MGP7W/38HLGUE",
url = "http://urlib.net/ibi/8JMKD3MGP7W/38HLGUE",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}