@PhDThesis{Jonah:2017:ObSi,
author = "Jonah, Olusegun Folarin",
title = "A study of daytime MSTIDs over equatorial and low latitude regions
during tropospheric convection: observations and simulations",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2017-02-17",
keywords = "TEC, daytime MSTIDs generation mechanisms, AGW activities,
convective weather activities, daytime MSTIDs geomagnetic
conjugate mappings, mecanismos de gera{\c{c}}{\~a}o de MSTIDs
diurnos, AGW atividade, atividade climat{\'e}rica convectiva,
mapeamento do conjugado geomagn{\'e}tico MSTIDs diurno.",
abstract = "Medium Scale Travelling Ionospheric Disturbances (MSTIDs) are the
highly dynamical phenomenona covering all latitudes in the F
region ionosphere and they propagate a long distance, often in the
form of wave-fronts. Their presence in a wide region pose threat
to the radio propagation and trigger the equatorial plasma bubble
which disrupts the GNSS navigation system. Atmospheric Gravity
Wave (AGW) is believed to be the cause of these MSTIDs during
daytime. However, the seeding mechanism of these AGWs is still a
research question. The objective of this thesis is to study the
dynamics of daytime MSTIDs over Brazil using detrended TEC, with
focus on understanding their propagation characteristics. In
addition, this thesis also presents novel results on daytime
MSTIDs geomagnetic conjugate mapping characteristics and
mechanisms responsible. Both observational and theoretical tools
are employed to pursue these objectives. Observational data
obtained using instruments such as a network of GNSS receivers,
digisonde, low-orbiting satellites (COSMIC) and meteorological
satellites (GOES Satellite) are analyzed to identify the driving
source of MSTIDs-AGW. Interesting characteristics associated with
the widely pursued convective-AGWs driven generation mechanism
from past literatures, are investigated. This mechanism is further
studied theoretically, by adapting a
Convectional-Atmosphere-Ionosphere-Coupled model (CAI-CM) to
incorporate the dynamics of convectively generated AGWs and their
coupling to the ionosphere. The numerical simulation work also
utilizes the SAMI3 (Sami3 is Another Model of the Ionosphere)
model to capture the fundamental physics of the ionosphere. The
SAMI3 model is used to simulate a large region of the ionosphere
for the self-consistent development of MSTIDs. Finally the
simulated MSTIDs from both CAI-CM and SAMI3 model are compared
with the observed MSTIDs. RESUMO: Os Dist{\'u}rbios
ionosf{\'e}ricos propagantes de m{\'e}dia escala (MSTIDs)
s{\~a}o fen{\^o}menos altamente din{\^a}micos que cobrem todas
as latitudes na ionosfera da regi{\~a}o F e propagam uma longa
dist{\^a}ncia, geralmente sob a forma de frentes de onda. Suas
presen{\c{c}}as em uma regi{\~a}o ampla afetam a
propaga{\c{c}}{\~a}o de r{\'a}dio e podem gerar a bolha de
plasma equatorial, a qual por sua vez pode interromper o sistema
de navega{\c{c}}{\~a}o GNSS. Acredita-se que a Onda de Gravidade
Atmosf{\'e}rica (AGW) seja a causa destes MSTIDs durante o dia.
No entanto, o mecanismo de gera{\c{c}}{\~a}o destas AGWs ainda
{\'e} uma quest{\~a}o de pesquisa. O objetivo desta tese {\'e}
estudar a din{\^a}mica das MSTIDs diurnas sobre o Brasil
utilizando TEC ap{\'o}s a remoc{\~a}o da tend{\^e}ncia, com
foco na compreens{\~a}o de suas caracter{\'{\i}}sticas de
propaga{\c{c}}{\~a}o. Al{\'e}m disso, esta tese tamb{\'e}m
apresenta novos resultados sobre as caracter{\'{\i}}sticas de
mapeamento do conjugado geomagn{\'e}tico do MSTID diurno e os
mecanismos respons{\'a}veis. Ambos instrumentos observacionais e
te{\'o}ricos s{\~a}o empregados para atingir esses objetivos. Os
dados observacionais obtidos usando instrumentos como uma rede de
receptores GNSS, digissonda, sat{\'e}lites de baixa {\'o}rbita
(COSMIC) e sat{\'e}lites meteorol{\'o}gicos (GOES) s{\~a}o
analisados para identificar os mecanismos de gera{\c{c}}{\~a}o
das MSTIDs-AGW. S{\~a}o investigadas caracter{\'{\i}}sticas
interessantes associadas ao mecanismo de gera{\c{c}}{\~a}o por
AGWs convectivas amplamente persquisadas em literaturas passadas.
Este mecanismo {\'e} ainda estudado teoricamente, adaptando um
modelo Convectional-Atmosphere- Ionosphere-Coupled (CAI-CM) para
incorporar a din{\^a}mica de AGWs convectivamente geradas e seu
acoplamento com a ionosfera. O trabalho de simula{\c{c}}{\~a}o
num{\'e}rica tamb{\'e}m utiliza o modelo SAMI3 (Sami3 {\'e}
Outro Modelo da Ionosfera) para capturar a f{\'{\i}}sica
fundamental da ionosfera. O modelo SAMI3 {\'e} usado para simular
uma grande regi{\~a}o da ionosfera para o desenvolvimento
auto-consistente de MSTIDs. Finalmente, as MSTIDs simuladas do
modelo CAI-CM e SAMI3 s{\~a}o comparadas com as MSTIDs
observadas.",
committee = "Alves, Maria Virginia (presidente) and Paula, Eurico Rodrigues de
(orientador) and Kherani, Esfhan Alam (orientador) and Pimenta,
Alexandre Alvares and Valladares, Cesar and Oliveira,
Virg{\'{\i}}nia Klausner de",
copyholder = "SID/SCD",
englishtitle = "Um estudo de MSTIDs do dia por regi{\~o}es equatoriais e baixa
latitude durante a convec{\c{c}}{\~a}o troposf{\'e}rica:
observa{\c{c}}{\~o}es e simula{\c{c}}{\~o}es",
language = "en",
pages = "187",
ibi = "8JMKD3MGP3W34P/3NAAB2L",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3NAAB2L",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}