Würzburg 2018 – scientific programme

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EP: Fachverband Extraterrestrische Physik

EP 3: Sun and Heliosphere I - Structure (MHD, Corona, TR, SW-acc.-Region)

EP 3.6: Talk

Tuesday, March 20, 2018, 18:00–18:15, BSZ - Pabel HS

Magnetohydrodynamic calculation of the temperature and wind velocity profile of the solar transition region — Todor Mishonov and •Albert Varonov — Department of Theoretical Physics, Faculty of Physics,
St. Clement of Ohrid University at Sofia, 5 James Bourchier Blvd., BG-1164 Sofia, Bulgaria

The mechanism of the solar corona heating still remains unexplained, almost 80 years after the discovery of the million degree hot solar corona. Observations show that the temperature increases two orders of magnitude in the transition region (TR), the boundary between the solar chromosphere and the solar corona. We are giving a detailed magnetohydrodynamic (MHD) calculation of the height dependence of the temperature and solar wind velocity. The temperature and solar wind velocity profiles are calculated for static frequency dependent spectral density of incoming MHD waves, no time dependent computer simulations have been performed. Heated by the MHD waves, the background plasma temperature increases leading to strong plasma viscosity increase, which results in more efficient MHD wave absorption. Within this calculation, the width of the TR is also evaluated by maximal value of the logarithmic derivative of the temperature. In such a way after 70 years we have returned to the original Alfvén idea [H. Alfvén, Granulation, Magneto-hydrodynamic waves, and the heating of the solar corona, MNRAS 107, Issue 2, pp. 211-219, (1947)] that corona is heated by AW.