Is Magnetic Topology Important for Heating the Solar Atmosphere?
arXiv:1505.05701 · doi:10.1098/rsta.2014.0264
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.
22 pages, 5 pages
References in corpus (15)
- A Contemporary View of Coronal Heating
- Generalized Squashing Factors for Covariant Description of Magnetic Connectivity in the Solar Corona
- MHD wave propagation in the neighbourhood of a two-dimensional null point
- The Number Of Magnetic Null Points In The Quiet Sun Corona
- The effect of the relative orientation between the coronal field and new emerging flux: I Global Properties
- Non-linear Tearing of 3D Null Point Current Sheets
- A new view of quiet-Sun topology from Hinode/SOT
- MHD mode coupling in the neighbourhood of a 2D null point
- Magnetohydrodynamic evolution of magnetic skeletons
- The Solar Cycle Variation of Topological Structures in the Global Solar Corona
- Linear and nonlinear MHD mode coupling of the fast magnetoacoustic wave about a 3D magnetic null point
- Three-Year Global Survey of Coronal Null Points from Potential-Field-Source-Surface (PFSS) Modeling and Solar Dynamics Observatory (SDO) Observations
- Dynamical Relaxation of Coronal Magnetic Fields. III. 3D Spiral Nulls
- Evidence of Electron Acceleration around the Reconnection X-point in a Solar Flare
- The onset of Impulsive Bursty reconnection at a two-dimensional current layer