Abstract
Magnetic fields permeate the entire solar atmosphere weaving an extremely
complex pattern on both local and global scales. In order to understand the
nature of this tangled web of magnetic fields, its magnetic skeleton, which
forms the boundaries between topologically distinct flux domains, may be
determined. The magnetic skeleton consists of null points, separatrix surfaces,
spines and separators. The skeleton is often used to clearly visualize key
elements of the magnetic configuration, but parts of the skeleton are also
locations where currents and waves may collect and dissipate.
In this review, the nature of the magnetic skeleton on both global and local
scales, over solar cycle time scales, is explained. The behaviour of wave
pulses in the vicinity of both nulls and separators is discussed and so too is
the formation of current layers and reconnection at the same features. Each of
these processes leads to heating of the solar atmosphere, but collectively do
they provide enough heat, spread over a wide enough area, to explain the energy
losses throughout the solar atmosphere? Here, we consider this question for the
three different solar regions: active regions, open-field regions and the quiet
Sun.
We find that the heating of active regions and open-field regions is highly
unlikely to be due to reconnection or wave dissipation at topological features,
but it is possible that these may play a role in the heating of the quiet Sun.
In active regions, the absence of a complex topology may play an important role
in allowing large energies to build up and then, subsequently, be explosively
released in the form of a solar flare. Additionally, knowledge of the intricate
boundaries of open-field regions (which the magnetic skeleton provides) could
be very important in determining the main acceleration mechanism(s) of the
solar wind.
Users
Please
log in to take part in the discussion (add own reviews or comments).