Dynamical phenomena in stratified solar coronal plasma

Different dynamical phenomena in the solar corona are investigated in the
present Thesis. We aim to investigate using a semi-analytical approach of the
effect of the surrounding environment on the period ratio of the fundamental
to first harmonic of a thin coronal loop. Investigation of geometrical effects are
taken into account, namely asymmetry of the coronal loop, i.e. its deviation
from a semi-circular shape.
It is found that if we are to obtain more accurate estimates on the effect
of the environment on the transversal oscillations of a coronal loop, we have
to take into account that in reality a coronal loop depends on more than one
coordinate, secondly, isothermal supposition of the loop and its environment
also need refinement, as observations show that the loops are not always in
hydrostatic equilibrium. The study on the expansion of a coronal loop indicates
that in order to have more realistic results one would need to include damping
processes, resonant absorption and cooling processes. Further in an expanding
loop, the growth of the amplitude due to emergence and decay of amplitude due
to resonant damping or cooling will be competing processes. When it expands,
a loop can also have accelerated motion upwards in the corona with cross section
modification of the
ux tube.
The final piece of work in this thesis is a numerical investigation into a 2D
magnetic reconnection process, where we study reconnection rates and how different
parameters such as resistivity and Hall term affect the process of field line
reconnection. The Hall effect does speed up the reconnection process, but it
depends significantly on the initial conditions of the problem. These initial conditions,
i.e. different magnetic field configuration, density stratification, gravity
play an important role in the reconnection process.