Abstract
The behavior of steady siphon flows along thin, arched magnetic flux tubes in the solar atmosphere is discussed, with particluar attention to the case of “flexible” flux tubes in the solar photosphere, where the plasma beta is of order unity. Qualitative features of subcritical and supercritical siphon flows are illustrated by the simple case of isothermal flow in an isothermal external atmosphere. More realistic flows, including representations of the temperature-stratified external solar atmosphere, the radiative transfer of energy between the flux tube and its surroundings, and variable ionization fraction along the flow are also discussed. The jump conditions for an adiabatic tube shock in a supercritical siphon flow are analyzed in some detail. Siphon flows have been detected in intense photospheric flux tubes arching across a magnetic neutral line on the Sun. Siphon flows also offer the most plausible explanation of the Evershed effect in sunspots. Recent observational and theoretical evidence concerning the siphon-flow model of the Evershed effect is discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
