| Abstract : | Magnetic field generated by the magnetohydrodynamic dynamo mechanism in the Sun’s interior threads through the surface and extends into our heliosphere via the sparsely dense but million degree hot solar corona. The structure and evolution of the solar coronal magnetic field driven by the surface motion of plasma modulates our space environment. The modulation manifests across different timescales, covering transient phenomena such as flares, coronal mass ejections and energetic particle events in short-term to long-term driving of solar irradiance, plasma winds, open flux and cosmic ray flux in the heliosphere. However, direct observation of coronal magnetic fields remains an outstanding challenge owing to low coronal plasma density and bright surface radiation in the background, requiring extremely sensitive polarization measurements. Coronal magnetic field models driven by the available observations serve an important purpose in this context. It is during a total solar eclipse when the bright photospheric emission is suppressed by the occulting Moon, we can test and constrain our predictive capabilities of theoretical models by comparing the global coronal magnetic field structure and emission characteristics with the observations. Also, observation of cosmic ray flux variation provides key insights to long-term forcing of coronal magnetic fields via solar dynamo and its impact on the heliosphere at different solar activity epochs. In this thesis we discuss the prediction of global coronal magnetic field structure and polarization characteristics during a total solar eclipse, long-term forcing of coronal magnetic fields and interaction of magnetic flux ropes with the ambient large-scale magnetic fields using various coupled theoretical models of solar interior, surface and corona. |
