2018
Ref: CTALK-2018-0069

A MODEL OF TURBULENT DYNAMO FOR PARTICLE ACCELERATION IN LOW CORONA: EVIDENCES DEDUCED FROM THE SDO EUV FLARES DATABASE

Podladchikova, 0 ; Kraaikamp, E ; Verbeeck, C


Talk presented at Solar Wind 15, Brussels, Belgium on 2018-06-19

Abstract: Coronal physics is dominated by two major problems: solar wind acceleration and coronal heating[1]. Parker proposed that low solar corona could be heated by the dissipation at many small-scale tangential discontinuities arising spontaneously in the coronal magnetic fields braided and twisted by random photospheric footpoint motions (so-called DC mechanism[2]). AC mechanism or wave dissipation, is obviously responsible for magnetic energy dissipation in the middle corona, at 2-10 solar radii[3]. Majority of the models of coronal heating based on the dissipation of small-scale current sheets assumes energy injection at large scales by photospheric motions. However due to the turbulent nature of these motions, excitation mechanisms may occur on a wide range of scales[4,5,6]. We present the first results of a new low solar coronal heating and particle acceleration model subject to multi-scale magnetic driving and dissipation. The model consists of two elements, the magnetic field source supposed to be associated with the small scale hydrodynamic turbulence[7] convected from the photosphere and local dissipation of small scale currents. The dissipation is assumed to be provided by either current instabilities due to anomalous resistivity or by the magnetic reconnection partially transferring energy to acceleration particles. We study the influence of cinematic dynamo or alpha-effect (see Fig.1) - mechanism of magnetic field generation on the Sun proposed by Parker[7] - on the properties of the heat and acceleration particle characteristics. We select the appropriated magnetic drivers and dissipation mechanisms while validating model results with SDO EUV flare database produced by Solar Demon tool[8]. References [1] J. A. Klimchuk, On solving the coronal heating problem,Solar Physics, 234, 2006, 41–77. [2] E. N. Parker, Nanoflares and the solar X-ray corona. ApJ, 330, 1988, 474–479. [3] M. Velli [4] O. V. Podladchikova [5] M. Baiesi, C. Maes, B. Shergelashvili, Correlated flares in models of a magnetized “canopy”,Physica A, 387, 167-176. [6] New [7] E. N. Parker, Hydromagnetic Dynamo Models. ApJ, 122, 1955, 293+.

Keyword(s): SDO, Solar Orbiter, Solar Demon, coronal heating, particle acceleration
Links: link
Funding: STCE/STCE/STCE


The record appears in these collections:
Conference Contributions & Seminars > Conference Talks > Contributed Talks
Royal Observatory of Belgium > Solar Physics & Space Weather (SIDC)



 Record created 2018-09-20, last modified 2018-09-20