Solar Tornados - Myth or Reality?
Abstract
Resent high-resolution observations from the Solar Dynamic Observatory have reawakened interest in an old and fascinating phenomenon of "solar tornados". This class of prominences was first introduced by E. Pettit in 1932, who studied them over many years up to 1950. Observations of solar tornados similar to the ones seen by SDO were already documented in 1875 by Secchi in his famous "Le Soleil". So, what are solar tornados - myth or reality? Thanks to SDO high resolution and high cadence multi-wavelength data, we can now answer this question. We introduce two types of solar tornados, types I and II. We show that a Type I tornado is the projection on the solar limb of the mostly 2D counter-streaming plasma motion along prominence spine and barbs. Type II tornados, on the other hand, consist in more 3D plasma motion following the sheared magnetic fields inside and along the prominence cavity, also projected on the limb. In other words, the "tornado" impression types results from the projection of plasma motions along magnetic lines, rather than a general vortical motion around a vertical or radial axis.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2012)
- Pub Date:
- June 2012
- Bibcode:
- 2012shin.confE.215P