@PhDThesis{Resende:2014:EsSoFo,
author = "Resende, L{\'a}ysa Cristina Araujo",
title = "Estudo sobre a forma{\c{c}}{\~a}o e domin{\^a}ncia das camadas
E-espor{\'a}dicas considerando a competi{\c{c}}{\~a}o entre
ventos e campos el{\'e}tricos",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2014",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2014-10-20",
keywords = "ionosfera, camadas E-espor{\'a}dicas, ventos, campos
el{\'e}tricos, ionosphere, sporadic E-layers, winds, eletric
fields.",
abstract = "Este trabalho apresenta um estudo sobre a forma{\c{c}}{\~a}o e
domin{\^a}ncia das camadas E-espor{\'a}dicas de bloqueio,
\$Es_{b}\$, considerando a competi{\c{c}}{\~a}o entre ventos e
campos el{\'e}tricos para duas regi{\~o}es
{\'{\i}}onosf{\'e}ricas brasileiras, S{\~a}o Lu{\'{\i}}s,
uma regi{\~a}o equatorial, e Cachoeira Paulista, que se situa em
baixa latitude. Neste contexto, foram utilizados dois m{\'e}todos
de an{\'a}lise. O primeiro se refere par{\^a}metros de
frequ{\^e}ncia obtidos em ionogramas, a saber: \emph{fo}Es
(frequ{\^e}ncia m{\'a}xima do tra{\c{c}}o ordin{\'a}rio) e
\emph{fb}Es (frequ{\^e}ncia de bloqueio). J{\'a} o segundo
m{\'e}todo consistiu no aprimoramento de um modelo te{\'o}rico
da regi{\~a}o E, chamado MIRE, para que fosse poss{\'{\i}}vel
simular a din{\^a}mica das camadas \$ES_{b}\$ levando em
considera{\c{c}}{\~a}o ventos e campos el{\'e}tricos
observacionais. Dessa forma, foi poss{\'{\i}}vel verificar o
efeito de ambos na forma{\c{c}}{\~a}o das camadas Es
atrav{\'e}s de simula{\c{c}}{\~o}es e compar{\'a}-los com os
dados observacionais. Os resultados confirmam a import{\^a}ncia
dos ventos na forma{\c{c}}{\~a}o de camadas \$Es_{b}\$. Com
rela{\c{c}}{\~a}o aos campos el{\'e}tricos, verificou-se que
eles s{\~a}o mais eficazes na regi{\~a}o de S{\~a}o
Lu{\'{\i}}s, onde se constatou que quando h{\'a} a
presen{\c{c}}a de irregularidades no plasma nesta regi{\~a}o, os
campos el{\'e}tricos verticais inibem a forma{\c{c}}{\~a}o das
camadas \$Es_{b}\$. Al{\'e}m disso, para complementar este
estudo, foram analisados dois eventos de tempestades
magn{\'e}ticas em que ocorreram penetra{\c{c}}{\~a}o de campos
el{\'e}tricos, a fim de averiguar o comportamento das camadas Es
via simula{\c{c}}{\~a}o nessas condi{\c{c}}{\~o}es. Nesta
an{\'a}lise simplificada, foi observado que as camadas
\$ES_{b}\$ obtidas nas simula{\c{c}}{\~o}es foram menos
expressivas quando a componente vertical do campo el{\'e}trico
perturbado foi considerada. Por fim, este trabalho possibilitou
uma an{\'a}lise mais real{\'{\i}}stica envolvendo
simula{\c{c}}{\~o}es e dados observacionais da din{\^a}mica de
forma{\c{c}}{\~a}o das camadas Es, que validou os mecanismos de
competi{\c{c}}{\~a}o entre ventos e campos el{\'e}tricos.
ABSTRACT: This work presents a study on the formation and
dominance of blankenting sporadic E-layers, \$Es_{b}\$,
considering the competition between winds and electric fields for
two Brazilian ionospheric regions, S{\~a}o Lu{\'{\i}}s, an
equatorial region, and Cachoeira Paulista, which is a low station.
In this context, two rnethods were used. The first refers to
analysis of the frequency parameters obtained from ionograms:
\emph{fo}Es (rnaximum frequency of the ordinary trace) and
\emph{fb}Es (blankenting frequency). The second method consisted
in the improvement of a theoretical model for the E region, MIRE,
in arder to sirnulate the dynamics of \$ES_{b}\$ layers taking
into account winds and electric fields observations. In that way,
it was possible to evaluate the effect of both, wind anel electric
field, in the Es layer formation through simulations and compare
it with observational data. The results confirrned the
significance of winds in \$ES_{b}\$ formation. The electric
fields were found to be more effective over S{\~a}o Lu{\'{\i}}s
was found that in the presence of plasma irregularities in that
region, the vertical electric fields inhibit the \$ES_{b}\$
formation. In addition, to cornplement this study, two magnetic
storrn events, during which disturbed electric fields penetrated
from high to low latitudes, were analyzed in arder to verify the
behavior of Es layers via simulation. In this simplified analysis,
it was observed that the \$ES_{b}\$ layers simulated were less
expressive when the vertical component of the disturbed electric
field was considered. Finally, this work has provided a more
realistic analysis involving simulations and observational data of
Es layers dynamics, which validated the competition mechanisrns
between winds and electric fields.",
committee = "Dal Lago, Alisson (presidente) and Batista, Inez Staciarini
(orientadora) and Nardin, Clezio Marcos de (orientador) and Abdu,
Mangalathayil Ali and Batista, Paulo Prado and Carrasco, Alexander
Jos{\'e} and Lima, Lourivaldo Mota",
copyholder = "SID/SCD",
englishtitle = "Study about the formation and dominance of the sporadic e layers
considering the competition between winds and electric fields",
language = "pt",
pages = "214",
ibi = "8JMKD3MGP5W34M/3H52UHS",
url = "http://urlib.net/ibi/8JMKD3MGP5W34M/3H52UHS",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}