Bibcode
Sánchez-Almeida, J.
Bibliographical reference
Magnetic Coupling between the Interior and Atmosphere of the Sun, Astrophysics and Space Science Proceedings. ISBN 978-3-642-02858-8. Springer-Verlag Berlin Heidelberg, 2010, p. 210
Advertised on:
2010
Citations
0
Refereed citations
0
Description
We describe a scenario for the topology of the magnetic field in
penumbrae that accounts for recent observations showing upflows,
downflows, and reverse magnetic polarities. According to our conjecture,
short narrow magnetic loops fill the penumbral photosphere. Flows along
these arched field lines are responsible for both the Evershed effect
and the convective transport. This scenario seems to be qualitatively
consistent with most existing observations, including the dark cores in
penumbral filaments reported by Scharmer et al. Each bright filament
with dark core would be a system of two paired convective rolls with the
dark core tracing the common lane where the plasma sinks down. The
magnetic loops would have a hot footpoint in one of the bright filament
and a cold footpoint in the dark core. The scenario fits in most of our
theoretical prejudices (siphon flows along field lines, presence of
overturning convection, drag of field lines by downdrafts, etc). If the
conjecture turns out to be correct, the mild upward and downward
velocities observed in penumbrae must increase upon improving the
resolution. This and other observational tests to support or disprove
the scenario are put forward.