Study of solar eruptive phenomena using in-situ data from spacecraft and ground stations

Doctoral Dissertation uoadl:1309029 1475 Read counter

Unit:
Τομέας Αστροφυσικής, Αστρονομίας και Μηχανικής
Library of the School of Science
Deposit date:
2014-07-14
Year:
2014
Author:
Μητσάκου Ελευθερία
Dissertation committee:
Ξ. Μουσάς Καθηγητής ΕΚΠΑ (Επιβλέπων), Π. Πρέκα-Παπαδήμα Επικ. Καθηγήτρια ΕΚΠΑ, Ε. Χριστοπούλου-Μαυρομιχαλάκη Καθηγήτρια ΕΚΠΑ
Original Title:
Μελέτη ηλιακών εκρηκτικών φαινομένων με μετρήσεις από δορυφόρους και επίγειους σταθμούς
Languages:
Greek
Translated title:
Study of solar eruptive phenomena using in-situ data from spacecraft and ground stations
Summary:
In this thesis, we study the interplanetary coronal mass ejections (ICMEs) that
occurred in the region near Earth, during the solar cycle 23.
ICMEs which are the interplanetary signatures of the coronal mass ejections
(CMEs) of the Sun, are of the most important events taking place in the
interplanetary medium and can affect in different ways the Earth and the human
existence and activity, with their interaction with the Earth's magnetosphere
The solar cycle 23, which is the last completed solar cycle (1996-2008) is
special and important in many aspects, not only because of its peculiarity, but
also because during this solar cycle we have huge amounts of data, that we can
study. Moreover, since this particular cycle CMEs began to be consistently
recorded.
In the first chapter, we refer to some theoretical and historical information
about the Sun and its characteristics.
In the second chapter, we analyze the basic characteristics of CMEs and their
interplanetary signatures (ICMEs). We mention their typical creation models,
the ways in which they may be monitored, various phenomena which they can be
associated with and their main impacts on space weather .
In the third chapter, we create a new catalogue of ICMEs, which we identified
in the region near the Earth during the solar cycle 23, via in-situ data. In
each event we identify the boundaries of the main core of the ICME and its
sheath and indicate whether or not they are accompanied by a shock wave. We
study their occurrence rates during the solar cycle, and occurrence rates of
CMEs observed on the Sun. We compare our results with other published
catalogues.
In the fourth chapter we study the possible correlations between ICME and
sheath parameters. We study the : magnetic field strength, speed, proton
density and temperature, plasma beta, duration and radial width. We present the
most important scatter plots and calculate the linear correlation coefficients.
In the fifth chapter we create typical profiles of the ICME parameters by
applying superposed epoch analysis. We also study the reaction of the Earth's
magnetic field with the Dst index. The events have been divided into different
categories in relevance to the existence of a shock and the phase of solar
cycle 23 in which they are observed.
In the sixth chapter we analyze the temporal evolution of characteristic ICME
during solar cycle 23 in order to reveal possible correlations and repeating
patterns.
In the seventh chapter we statistically study the identified ICMEs and derive
their typical characteristics and distribution histograms, as well as, of their
sheaths and background, during solar cycle 23. We compare our results with
other published articles.
In the eighth chapter we perform statistical analysis on the 12 different
categories in which we separated our events and compare them to each other, in
order to reveal possible patterns.
In the ninth chapter we summarize the main results of the thesis and suggest
ideas on new studies that can be performed in the future.
Keywords:
Interplanetary coronal mass ejection, Statistical properties, Sheath, Catalog, Solar Cycle 23
Index:
No
Number of index pages:
0
Contains images:
Yes
Number of references:
178
Number of pages:
XVI, 259
File:
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