@PhDThesis{Marchezi:2020:EvULAc,
author = "Marchezi, Jos{\'e} Paulo",
title = "Evaluation of ULF activity on the electron transportation in the
outer radiation belt",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2020",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2020-05-19",
keywords = "Radiation belts, ULF waves, magnetosphere, diffusion coefficients,
cintur{\~o}es de radia{\c{c}}{\~a}o, ondas ULF, magnetosfera,
coeficiente de difus{\~a}o.",
abstract = "Van Allens radiation belts consist of two regions with entrapment
of charged particles in the Earths magnetic field: inner and outer
belts. The inner belt is composed mainly of protons with energies
between 100 keV and a few hundred MeV. The outer belt is primarily
consisting of high-energy electrons, ranging from dozens of keV to
a few dozen MeV. Those particles rotate around the field line,
mirroring movement along the magnetic field line and a drift
movement around the Earth. Each movement has a particular time and
is associated with an adiabatic invariant. Changes in the
configuration of the solar magnetic field influence the solar wind
and, consequently, all planets and spaceships within the
heliosphere can be affected by disturbances of the solar wind.
Interplanetary Coronal Mass Ejections (ICME) and fast solar wind
High-Speed Streams (HSS), cause disturbances in the Earths
magnetosphere, including radiation belts from Van Allen. ICME
events are more frequent during the growing phase of the solar
cycle, while HSS is more critical during the declining period. The
characteristics of the disturbances observed in the flux of
electrons from the outer radiation belt due to these events are
also different. Since October 2012, NASA initiated the Van Allen
Probes mission that monitors, among other parameters, the magnetic
field and the variation of particles in the radiation belts. The
main objective of this work is to describe, based on observational
data, the radial diffusion mechanism in the presence of ULF waves.
For this, it is necessary to explain the role of ULF waves in the
frequency bands corresponding to the natural oscillations of the
magnetosphere, that is, Pc4 and Pc5, observed in the region of the
external radiation belt, during periods of increased relativistic
electron flux in the outer radiation belt. The energy penetration
capacity as a function of the L-shell of the magnetosphere was
investigated for the different frequency ranges considered in this
research. The radiation belt events were investigated when related
to HSS and ICME occurrences. Statistical results considering all
ICMEs and HSS during the Van Allen Probes era show that for both
solar wind structures, solar wind plasma parameters are strongly
related to the radiation belt response at L \− shell = 5
RE, and on average they show a higher magnitude compared to those
related to decrease in particle flux. Also, the ULF wave power is
obtained as being more intense throughout enhancement events.
Finally, we compare the integrated ULF wave power measured by the
satellites and obtained via empirical modeling, for each L-shell,
the results show that the empirical model overestimates integrated
power for all the investigated L-shells and it discrepancy is
increased at higher L-shells. RESUMO: Os cintur{\~o}es de
radia{\c{c}}{\~a}o de Van Allen consistem em duas regi{\~o}es
com aprisionamento de part{\'{\i}}culas carregadas no campo
magn{\'e}tico da Terra: cintur{\~a}o interno e externo. O
cintur{\~a}o interno {\'e} composto principalmente de
pr{\'o}tons com energias entre 100 keV e algumas centenas de MeV.
O cintur{\~a}o externo, {\'e} composto principalmente por
el{\'e}trons de altas energias, variando de dezenas de keV e
algumas dezenas de MeV. Essas part{\'{\i}}culas realizam
tr{\^e}s movimentos peri{\'o}dicos: giro em torno da linha de
campo, movimento de espelhamento ao longo da linha de campo
magn{\'e}tico e um movimento de deriva em torno da Terra. Cada
movimento possui um tempo caracter{\'{\i}}stico e est{\'a}
associado a um invariante adiab{\'a}tico. As mudan{\c{c}}as na
configura{\c{c}}{\~a}o do campo magn{\'e}tico solar influenciam
o vento solar e, consequentemente, todos os planetas e
espa{\c{c}}onaves dentro da heliosfera podem ser afetados por
perturba{\c{c}}{\~o}es do vento solar. As Eje{\c{c}}{\~o}es de
Massa Coronal Interplanet{\'a}rias (Interplanetary Coronal Mass
Ejection - ICMEs) e os feixes r{\'a}pidos do vento solar (High
Speed Streams - HSS), causam dist{\'u}rbios na magnetosfera da
Terra, incluindo os cintur{\~o}es de radia{\c{c}}{\~a}o de Van
Allen. Os eventos de ICME s{\~a}o mais frequentes durante a fase
crescente do ciclo solar, enquanto os HSS s{\~a}o mais
importantes durante a fase de decl{\'{\i}}nio. As
caracter{\'{\i}}sticas dos dist{\'u}rbios observados no fluxo
de el{\'e}trons do cintur{\~a}o de radia{\c{c}}{\~a}o externo
devido a esses eventos tamb{\'e}m s{\~a}o diferentes. Desde
outubro de 2012, a NASA iniciou a Miss{\~a}o Van Allen Probes que
monitora o campo magn{\'e}tico e a varia{\c{c}}{\~a}o de
part{\'{\i}}culas nos cintur{\~o}es de radia{\c{c}}{\~a}o. O
objetivo principal deste trabalho {\'e} descrever, a partir de
dados observacionais, o mecanismo de difus{\~a}o radial na
presen{\c{c}}a de ondas ULF. Para isso, {\'e} preciso descrever
o papel das ondas ULF nas faixas de frequ{\^e}ncias
correspondentes as oscila{\c{c}}{\~o}es naturais da
magnetosfera, ou seja, Pc3, Pc4 e Pc5, observadas na regi{\~a}o
do cintur{\~a}o externo de radia{\c{c}}{\~a}o, durante
per{\'{\i}}odos de aumento de fluxo de el{\'e}trons
relativ{\'{\i}}sticos no cintur{\~a}o externo de
radia{\c{c}}{\~a}o. Ser{\~a}o investigadas a capacidade de
penetra{\c{c}}{\~a}o de energia em fun{\c{c}}{\~a}o das
camadas L (L-shell) da magnetosfera, para as diferentes faixas de
frequ{\^e}ncia consideradas nessa pesquisa. Com a finalidade de
associar os eventos a perturba{\c{c}}{\~o}es geomagn{\'e}ticas,
ser{\~a}o considerados os eventos relacionados a ocorr{\^e}ncias
de HSS e ICME. Os resultados estat{\'{\i}}sticos, considerando
todos os ICMEs e HSS durante a era de Van Allen Probes, mostram
que, para ambas as estruturas de vento solar, os par{\^a}metros
do plasma de vento solar est{\~a}o fortemente relacionados {\`a}
resposta do cinto de radia{\c{c}}{\~a}o em L \− shell = 5
RE e, em m{\'e}dia, mostram uma magnitude maior em
compara{\c{c}}{\~a}o com aqueles relacionado {\`a}
diminui{\c{c}}{\~a}o do fluxo de part{\'{\i}}culas. Al{\'e}m
disso, a pot{\^e}ncia da onda ULF {\'e} obtida como sendo mais
intensa durante os eventos de aprimoramento. Por fim, comparamos a
pot{\^e}ncia de onda ULF integrada medida pelos sat{\'e}lites e
obtida por modelagem emp{\'{\i}}rica, valor de L-shell, os
resultados mostram que o modelo emp{\'{\i}}rico superestima a
pot{\^e}ncia integrada para cada valor de L-shell investigadas e
sua discrep{\^a}ncia {\'e} aumentada em L-shell mais altos.",
committee = "Alves, Maria Virginia (presidente) and Alves, L{\'{\i}}via
Ribeiro (orientadora) and Silva, L{\'{\i}}gia Alves da
(orientadora) and Sibeck, David Gary (orientador) and Silva Souza,
Vitor Moura Cardoso e and Lucas, Aline de and Rojas, Fl{\'a}via
Reis Cardoso",
englishtitle = "Avalia{\c{c}}{\~a}o da atividade de ondas ULF no transporte de
el{\'e}trons no cintur{\~a}o de radia{\c{c}}{\~a}o externo",
language = "en",
pages = "139",
ibi = "8JMKD3MGP3W34R/42GSLS8",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/42GSLS8",
targetfile = "publicacao.pdf",
urlaccessdate = "25 abr. 2024"
}