Temporal evolution of MHD waves in solar coronal arcades
[eng] In this thesis we will study vertical oscillations in a potential arcade under the approximation of a zero- plasma, when di erent density pro les are considered. On one hand we will focus on the time-dependent problem to analyze the other side of the magnetohydrodynamic oscillations coin which...
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| Format: | doctoral thesis |
| Status: | Published version |
| Publication Date: | 2019 |
| Country: | España |
| Institution: | CBUC, CESCA |
| Repository: | TDR. Tesis Doctorales en Red |
| OAI Identifier: | oai:www.tdx.cat:10803/671489 |
| Online Access: | http://hdl.handle.net/10803/671489 |
| Access Level: | Open access |
| Keyword: | Fisica solar Corona solar Oscilaciones Arcadas coronales Simulaciones numéricas Física Solar 53 |
| Summary: | [eng] In this thesis we will study vertical oscillations in a potential arcade under the approximation of a zero- plasma, when di erent density pro les are considered. On one hand we will focus on the time-dependent problem to analyze the other side of the magnetohydrodynamic oscillations coin which traditionally is given by the normal mode analysis. We are going to study the propagation, energy transformation and damping of the impulsively generated waves as well as its relevant spatial and temporal scales in order to complete the picture. In order to study the wave damping, we examine two physical mechanisms that may be involved in the fast attenuation of the observed vertical coronal loop oscillations, namely wave leakage through wave tunneling and resonant absorption. In this wok whenever is possible, the time-dependent results are going to be compared with known normal mode properties to gain knowledge of how both sides are related as well as to test them. On the other hand, we also will investigate the use of a new technique of obtaining the system normal modes when the standard normal mode analysis is di cult to be carried out. We will apply it to a straight coronal loop model and we will obtain them with the desired degree of accuracy thanks to several criteria based on the convergence of the method. |
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