Magnetized jets in the solar atmosphere

Observations show that the solar outer atmosphere (the solar corona) is much hotter than the solar photosphere. Due to radiation and thermal conduction the coronal plasma would cool off shortly without external heating sources. This is the long-standing coronal heating problem. Simple estimations show that the solar chromosphere, a thin layer sandwiched between the corona and the photosphere, has even higher energy losses. Therefore, the heating of chromospheric plasma is an equally important problem as the coronal heating. The mechanical energy of photospheric motions might compensate the energy losses in the chromosphere and corona, but the mechanism of energy transport and dissipation are not known. Recent high resolution observations revealed ubiquitous magnetized jets with different speeds, temperature and density. Magnetic field of these jets can be twisted by photospheric motions and eruption of new magnetic flux. These jets can be unstable due to magnetic twist and shear motions. The project aims to study the stability of magnetized jets in the chromosphere and corona, their role in plasma heating and destabilization of coronal large-scale magnetic structures. The project tasks include: (1) kink instability of rotating twisted jets, (2) Kelvin-Helmholtz instability and heating of twisted partially ionized chromospheric jets, (3) Strouhal instability of transversally moving magnetic flux tubes, (4) statistical relation of prominence tornadoes with coronal mass ejections (CMEs). Task 1-3 will be fulfilled by analytical and numerical solutions of magnetohydrodynamic equations. Task 4 will be fulfilled by analysis of observations from recent solar missions (Solar Dynamics Observatory and STEREO). The novel ideas of projects include the influence of rotation on kink instability in twisted magnetic flux tubes, the influence of neutral hydrogen atoms on the Kelvin-Helmholtz instability of twisted chromospheric jets, the influence of partial ionization on Strouhal instability of transversally moving magnetic tube, and the role of solar tornadoes (which are counterparts of terrestrial tornadoes) in the destabilization of prominences. The expected results of the project will have huge impact on solution of coronal and chromospheric heating and will improve space weather predictions considerably.

The Sun's atmosphere is much hotter than the photosphere. Due to the radiation and thermal conduction, the plasma would cool down in a short time without external heating sources. The mechanical energy of the photospheric movements can compensate for the energy losses in the chromosphere and corona. The magnetized jets with different speed, temperature and density can be unstable and heat the plasma. The primary scientific goal of the project was to study the stability of magnetized jets in the chromosphere and corona, and their role in plasma heating and destabilization of large magnetic coronal structures. The main results of the project are the kink instability and heating of cylindrical and triangular jets, Kelvin-Helmholtz instability of twisted partially ionized chromospheric jets, the first observation of Alfvén shock waves and their energy conversion in the chromosphere, and the statistical relationship of tornado prominences with coronal ones Mass Ejections (CMEs). The results of the project have major implications for solving the problem of coronal and chromospheric heating and forecasting space weather.