Dynamic phenomena and magnetism in solar corona

Our Sun is an active star. This activity impacts planet Earth and human society in numerous ways. Terrestrial climate, ozone concentrations in the stratosphere and atmospheric drag on satellites all respond to variations in the Sun`s radiative output. Astronauts, airline passengers, and satellite electronics are all affected by the energetic particles produced in solar flares and coronal mass ejections (CMEs). The electric power grid systems, communication and navigation nets can all be interrupted by geomagnetic storms driven by blasts in the solar wind. Such a close Sun-Earth con-nection makes the investigations of the Sun and its activity to be of vital importance. These inves-tigations are also actual for understanding of the behaviour of stars and space plasma in general. An essential requirement for understanding the Sun-Earth connection is understanding the cau-ses of solar variability and determining the mechanisms by which the energy generated in the Sun`s core is released into space. Magnetic field plays here the key role. Visible solar atmosphere has a highly dynamic and complex structure. It consists of a large number of constantly evolving loops and filaments, interacting with each other, which are closely associated with the local mag-netic field. By this, magnetic loops and flux tubes appear to be the main building blocks of the solar atmosphere. In fact, they represent the form in which the magnetic field exists in the Sun. The non-stationary character of these plasma-magnetic structures is closely related to the complex dynamic processes all over the Sun, from its inner regions, convection zone and photosphere to the corona. Solar energetic phenomena, associated with the dynamics of magnetic loops range from tiny transient brightenings (micro-flares) and jets to large, active-region-sized flares and CMEs. In our project we propose development of theoretical models and interpretation of observations, concerning the formation, dynamics, radiative and flaring phenomena in solar magnetic loops and prominences. The project appears to be actual in view of European and international currently operating (SOHO, TRACE, HESSI) and future (Solar Orbiter, STEREO, Solar-B, SDO) space missions. Be-sides, the proposed investigation will establish scientific tools for the planning and initiation of fu-ture European Space Agency and international space research programs.

Development of theoretical models and interpretation of observations of dynamic and energy release phenomena in the solar atmosphere formed the primary focus of the project. Its theoretical part comprised analytic approaches and numerical simulations aimed to quantify the complex processes in the solar plasmas, whereas the observational and data analysis activity dealt with application of advanced data analysis techniques to the data from modern solar space missions and observational programs. The sequence of theoretical investigations and simulations, performed within the project research program allowed to formulate and elaborate further a unified concept of the collective dynamical and energy release processes in the groups of inductively interacting current-carrying coronal magnetic loops (project goal (1)). The developed models are addressed to the phenomena of solar flares, CMEs, coronal loop oscillations, and associated effects of the electromagnetic emission generation and propagation. The quantitative comparative study and numerical simulation of MHD wave damping mechanisms and related energy release effects in the solar partially ionized plasmas (project goal (2)) provided the fundamental physical background for interpretation of a number of dynamical and energy release phenomena in the solar photosphere, chromosphere and prominences. The results of these investigations are of high importance for improvement and consequent development of existing paradigms and models regarding the energy transport through the solar atmosphere, origin and evolution of solar prominences, nature of coronal explosive and eruptive phenomena and coronal heating. Besides of that, a unique data analysis algorithm based on the combination of a "sliding window" Fourier (SWF) transform and the nonlinear Wigner-Ville (WV) method has been further elaborated and applied in the field of solar physics research. This algorithm allows detection of complex multi signal modulations in the analyzed data records and enables to obtain the dynamical spectra of these modulations, providing high sensitivity and spectralemporal resolution. In its present form the SWF-WV algorithm appears as a universal analytical tool applicable in a broad range of applied studies which is in principle not limited by only solar physics. During the project time, tests of the algorithm have been already made in the fields of stellar- and helio- seismology, planetary radio astronomy, exo-planetary search and economics. The results of these tests have shown high efficiency of the algorithm and opened broad perspectives for its further application in the multidisciplinary research.