Μελέτη ανάδυσης μαγνητικής ροής στην ηλιακή ατμόσφαιρα με χρήση αριθμητικών προσομοιώσεων
Φόρτωση...
Ημερομηνία
Συγγραφείς
Καραντάνης, Ευάγγελος
Karantanis, Evangelos
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Φυσικής
University of Ioannina. School of Sciences. Department of Physics
University of Ioannina. School of Sciences. Department of Physics
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
The subject of this master thesis is the study of magnetic flux emergence in the solar atmosphere using
numerical simulations.
It is well known that various phenomena in the Sun such as solar flares, jets, coronal mass ejections
(CME), are linked to magnetic structures beneath the photosphere. These structures transport magnetic
flux from the deep convection zone to the photosphere and then expand in the corona. In this thesis
we focus on the interaction between the emerging magnetic field and the external ambient field leading
to standard jet formation and more intense eruptions known as blowout jets. To quantify the amount
of energy and magnetic field transported into the solar atmosphere we conduct three-dimensional (3D),
resistive magnetohydrodynamic (MHD) numerical simulations using Lare3D code. This allows us to model
the emergence process and the eruptive phenomena produced in our simulations. The magnetic flux is
concentrated along rigid structures located in the convection zone and we examine different topologies of
those structures to understand how their characteristics affect the amount of energy that can emerge and
produce transient phenomena. Given the importance of the twist of the field lines in a flux tube, we compare
cases with higher (α = 0.4) and lower (α = 0.1) twists.
For the high twist case (α = 0.4) we find that both tubes produce multiple jets and blowout jets. The
horizontal tube releases a significant amount of energy in the corona as compared to the toroidal tube
however the toroidal tube maintains an eruptive behavior for longer time albeit with less intensity. We find
that the reasons behind these behavior is that the toroidal tube maintains and increases the amount of axial
flux located at the upper atmosphere whereas the horizontal tube after the first two intense eruptions can no
longer create and maintain axial flux which is an important factor since it is linked to the twisted magnetic
field lines that lead to eruptions. For the less twisted case (α = 0.1) the toroidal tube cannot produce any
eruptions given that the field lines emergence with almost no twist and there is no further shearing motion.
The horizontal tube, due to its undulation produces one eruption.
Overall, the geometrical structure of real magnetic flux tubes in the Sun is not well established therefore
numerical simulations can help identify these structures by comparing them with observational data from
eruptive phenomena on the Sun.
Περιγραφή
Λέξεις-κλειδιά
Ήλιος, Μαγνητοϋδροδυναμική, Ανάδυση μαγνητικής ροής, Sun, Magnetohydrodynamics, Magnetic flux emergence
Θεματική κατηγορία
Ηλιακή φυσική, Solar physics
Παραπομπή
Σύνδεσμος
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Φυσικής
University of Ioannina. School of Sciences. Department of Physics
University of Ioannina. School of Sciences. Department of Physics
Όνομα επιβλέποντος
Αρχοντής, Βασίλης
Εξεταστική επιτροπή
Αρχοντής, Βασίλης
Νίντος, Αλέξανδρος
Πατσουράκος, Σπύρος
Νίντος, Αλέξανδρος
Πατσουράκος, Σπύρος
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών
University of Ioannina. School of Sciences
University of Ioannina. School of Sciences
Πίνακας περιεχομένων
Χορηγός
Βιβλιογραφική αναφορά
Ονόματα συντελεστών
Αριθμός σελίδων
83