@PhDThesis{CondeCuellar:2017:3DMoMa,
author = "Conde Cuellar, Sandra Milena",
title = "3D model magneto-acoustic waves in coronal loops observed during
transient events",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2017-05-25",
keywords = "flares, waves, magnetohydrodynamic, relation to magnetic field,
structures, flares, ondas, magnetohidrodin{\^a}mica,
rela{\c{c}}{\~a}o com o campo magn{\'e}tico, estruturas.",
abstract = "We present a three-dimensional analysis of magneto-acoustic waves,
along the seven coronal loops, observed on the active region NOAA
11272 during the class B and C flares. We found 19-, 9-, 5-, 2-,
1-, and 0.6-minute waves using the pixelised wavelet filtering
method over images obtained from the Atmospheric Imaging Assembly
instrument. We modelled the velocity of these waves along the
extrapolated magnetic field lines that reproduce the observed
loops in extreme ultraviolet. The extrapolation was made over
magnetograms, got from the Helioseismic and Magnetic Imager
instrument, using the linear force-free approximation. From our
model, we found temperatures 10\$^{3}\$ (maior equivalente) T
(menor equivalente) 1.8 x 10\$^{7}\$ K and densities
10\$^{7}\$ (maior equivalente) n (menor equivalente)
10\$^{17}\$ cm\$^{\−3}\$, covering from photosphere to
corona, as expected in the solar atmosphere. Hence, we obtained
acoustic c\$_{s}\$ \$\approx\$ 10\$^{2}\$ km
s\$^{\−1}\$ and Alfv{\'e}nic \$\upsilon\$\$_{A}\$
\$\approx\$ 10\$^{4}\$ km s\$^{\−1}\$ velocities
values which are in agreement with the literature. In addition,
the brightness asymmetry observed along the coronal loops is
explained by the magnetic field and Alfv{\'e}n velocity
distributions along the extrapolated field lines. We found fast
magneto-acoustic waves at the beginning of B3.8 and C1.9 flares
and slow modes along the loops during all flares. Our 3D model
represents an unprecedented method to study waves in coronal
loops. All results are coherent with expected values in the solar
atmosphere conditions. RESUMO: Apresentamos uma an{\'a}lise
tridimensional de ondas magnetoac{\'u}sticas ao longo de sete
loops coronais, observados na regi{\~a}o ativa NOAA 11272 durante
os flares de classe B e C. Encontramos ondas de 19, 9, 5, 2, 1 e
0.6 minutos usando o m{\'e}todo Pixelised Wavelet Filtering sobre
imagens obtidas com o instrumento Atmospheric Imaging Assembly.
Modelamos as velocidades dessas ondas ao longo das linhas de campo
magn{\'e}tico extrapoladas que reproduzem os loops observados em
ultravioleta extremo. A extrapola{\c{c}}{\~a}o foi feita sobre
os magnetogramas obtidos com o instrumento Helioseismic and
Magnetic Imager, usando a aproxima{\c{c}}{\~a}o Linear
Force-Free. A partir do nosso modelo, encontramos temperaturas de
10\$^{3}\$ (maior equivalente) T (menor equivalente) 1.8 x
10\$^{7}\$ K e densidades de 10\$^{7}\$ (maior equivalente) n
(menor equivalente) 10\$^{17}\$ cm\$^{\−3}\$, cobrindo
desde a fotosfera at{\'e} a coroa, como esperado na atmosfera
solar. Desta forma, obtivemos valores para as velocidades
ac{\'u}stica e Alfv{\'e}nica de c\$_{s}\$ \$\approx\$
10\$^{2}\$ km s\$^{\−1}\$ e \$\upsilon\$\$_{A}\$
\$\approx\$ 10\$^{4}\$ km s\$^{\−1}\$
respectivamente, as quais est{\~a}o acorde com a literatura.
Adicionalmente, a assimetria no brilho observada ao longo dos
loops coronais {\'e} explicada pelas distribui{\c{c}}{\~o}es do
campo magn{\'e}tico e da velocidade Alfv{\'e}n ao longo das
linhas extrapoladas. N{\'o}s encontramos ondas
magnetoac{\'u}sticas r{\'a}pidas no inicio dos flares B3.8 e
C1.9 e modos lentos ao longo dos loops durante todos os flares. O
nosso modelo representa um m{\'e}todo in{\'e}dito para estudar
ondas em loops coronais. Todos os resultados s{\~a}o coerentes
com os valores esperados nas condi{\c{c}}{\~o}es da atmosfera
solar.",
committee = "Costa, C{\'e}sar Augusto (presidente) and Costa, Joaquim Eduardo
Rezende (orientador) and Viera, Luis Eduardo Antunes and Alves,
Maria Virg{\'{\i}}nia and Castro, Carlos Guillermo Gim{\'e}nez
de and Pereira, Vera Jatenco Silva and Silva Pereira, Vera
Jatenco",
englishtitle = "Modelo tridimensional de ondas magnetoac{\'u}sticas em ''loops''
coronais observados durante eventos transientes",
language = "en",
pages = "150",
ibi = "8JMKD3MGP3W34P/3NR6PP2",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3NR6PP2",
targetfile = "publicacao.pdf",
urlaccessdate = "28 abr. 2024"
}