This thesis presents the study of magnetohydrodynamic (MHO) waves and oscillations in quiet Sun chromospheric fine structures near the solar disk center using multiwavelength, high temporal and spatial resolution observations. Transverse oscillations in chromospheric on-disk mottles that appear to be rooted in photospheric magnetic bright points are detected with great accuracy and interpreted in terms of MHO kink waves. Measured kink wave characteristiCs, such as periods (ranging from 70 to 280 s and peak at -165-s), phase speeds 40-120-km S·l, and transverse velocity amplitudes (2-18 km S-l), are similar to results found for limb spicules. An analysis of oscillation signals at different positions along the mottles provides evidence for upward and downward propagating and standing transverse waves. Wave characteristics including the maximum transverse velocity amplitude and the phase speed are measured as a function of distance along the structure's length. Solar magnetoseismology (SMS) is applied to these measured parameters to obtain diagnostic information on key plasma parameters (e.g., magnetic field, density, temperature, flow speed) of these localized waveguides. Using the SMS tool, the magnetic field strength of the mottle along the -2 Mm length is found to decrease by a factor of 12, while the local plasma density scale height is -280±80-km.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:678708 |
| Date | January 2014 |
| Creators | Kuridze, D. |
| Publisher | Queen's University Belfast |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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