@InProceedings{SilviaSVARASDMCMAWALL:2024:WhCaAu,
author = "Silvia, Ligia Alves da and Shi, Jiankui and Vieira, Luis Eduardo
Antunes and Agapitov, Oleksiy and Resende, Laysa Cristina
Ara{\'u}jo and Alves, Livia Ribeiro and Sibeck, David G. and
Deggeroni, Vinicius and Marchezi, Jos{\'e} Paulo and Chen, Sony
Su and Moro, Juliano and Aras, Christina and Wang, Chi and
Andrioli, V{\^a}nia F{\'a}tima and Liu, Zhengkuan and Li, Hui",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{China-Brazil Joint Laboratory for Space Weather} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {China-Brazil Joint
Laboratory for Space Weather} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {China-Brazil Joint Laboratory for Space Weather} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto
Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {China-Brazil Joint Laboratory for Space
Weather} and {China-Brazil Joint Laboratory for Space Weather} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{China-Brazil Joint Laboratory for Space Weather} and
{China-Brazil Joint Laboratory for Space Weather}",
title = "Why Can the Auroral-Type Sporadic E Layer Be Detected Over the
South American Magnetic Anomaly (SAMA) Region? An Investigation of
a Case Study Under the Influence of the HighSpeed Solar Wind
Stream",
booktitle = "Proceedings...",
year = "2024",
organization = "Conferencia Latinoamericana de Geof{\'{\i}}sica Espacial, 14.",
abstract = "We present a study of the large amplitude longitudinal
oscillations observed in two solar filaments (F1 and F2), prior to
their eruptions. To analyze a possible implication of oscillations
in the precursor processes of eruptive events, we analyzed the F1
and F2 oscillation periods and their variations during the pre-
and post-eruption of filaments, the formation of coronal mass
ejection (CME) and the corresponding magnetic field evolution. The
F2 pre-eruption oscillations, exhibit a period of approximately 1
hour, aligning with previous reports. Applying a mathematical
model and assuming a plasma density of 1.6 x 1011 cm-3 (Luna, M.,
\& Karpen, J. 2012), we estimate the minimum magnetic field
values of 95G for F1 and 33G for F2. Our results show that the F2s
magnetic field is similar to previously reported values, while the
F1s magnetic field is unexpectedly high and challenges previous
estimations of the filaments magnetic field. In addition, we
establish a connection between the onset of observed longitudinal
oscillations and the appearance of new photospheric magnetic
fluxes, triggering a magnetic reconnection process. The F2
pre-eruption oscillations are related to the F2 eruption and
formation of the associated CME, while we note the absence of any
CME immediately after the F1 eruption; although, F1 also undergoes
pre-eruption oscillations, it is accompanied by a gradual and slow
expansion of F1, unlike the F2, leading to the F1 eruption and
formation of partial halo CME only four days after the onset of F1
expansion. A more detailed analysis, using wavelet techniques
reveals the temporal variations of oscillation periods, suggesting
a link with the filaments body expansion process and variation of
filaments geometric properties, particularly their curvature
radius. In summary, the proposed model indicates that the filament
oscillation periods and their variations are highly correlated
with the evolution of the filament geometric properties, the
linked magnetic configuration, their eruption and formation of
CMEs. More comprehensive studies are needed to verify our
results.",
conference-location = "Monterrey, Mexico",
conference-year = "08-12 Apr. 2024",
language = "en",
urlaccessdate = "21 maio 2024"
}