Tracing the magnetic field topology of the quiet corona using propagating disturbances. (arXiv:2206.11077v1 [astro-ph.SR])
<a href="http://arxiv.org/find/astro-ph/1/au:+Morgan_H/0/1/0/all/0/1">Huw Morgan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Korsos_M/0/1/0/all/0/1">Marianna Korsos</a>
The motion of faint propagating disturbances (PD) in the solar corona reveals
an intricate structure which must be defined by the magnetic field. Applied to
quiet Sun observations by the Atmospheric Imaging Assembly (AIA)/Solar Dynamics
Observatory (SDO), a novel method reveals a cellular network, with cells of
typical diameters 50arcsec in the cool 304AA channel, and 100arcsec in
the coronal 193AA channel. The 193AA cells can overlie several 304AA
cells, although both channels share common source and sink regions. The sources
are points, or narrow corridors, of divergence that occupy the centres of
cells. They are significantly aligned with photospheric network features and
enhanced magnetic elements. This shows that the bright network is important to
the production of PDs, and confirms that the network is host to the source
footpoint of quiet coronal loops. The other footpoint, or the sinks of the PDs,
form the boundaries of the coronal cells. These are not significantly aligned
with the photospheric network – they are generally situated above the dark
internetwork photosphere. They form compact points or corridors, often without
an obvious signature in the underlying photosphere. We argue that these sink
points can either be concentrations of closed field footpoints associated with
minor magnetic elements in the internetwork, or concentrations of
upward-aligned open field. The link between the coronal velocity and magnetic
fields is strengthened by a comparison with a magnetic extrapolation, which
shows several general and specific similarities, thus the velocity maps offer a
valuable additional constraint on models.
The motion of faint propagating disturbances (PD) in the solar corona reveals
an intricate structure which must be defined by the magnetic field. Applied to
quiet Sun observations by the Atmospheric Imaging Assembly (AIA)/Solar Dynamics
Observatory (SDO), a novel method reveals a cellular network, with cells of
typical diameters 50arcsec in the cool 304AA channel, and 100arcsec in
the coronal 193AA channel. The 193AA cells can overlie several 304AA
cells, although both channels share common source and sink regions. The sources
are points, or narrow corridors, of divergence that occupy the centres of
cells. They are significantly aligned with photospheric network features and
enhanced magnetic elements. This shows that the bright network is important to
the production of PDs, and confirms that the network is host to the source
footpoint of quiet coronal loops. The other footpoint, or the sinks of the PDs,
form the boundaries of the coronal cells. These are not significantly aligned
with the photospheric network – they are generally situated above the dark
internetwork photosphere. They form compact points or corridors, often without
an obvious signature in the underlying photosphere. We argue that these sink
points can either be concentrations of closed field footpoints associated with
minor magnetic elements in the internetwork, or concentrations of
upward-aligned open field. The link between the coronal velocity and magnetic
fields is strengthened by a comparison with a magnetic extrapolation, which
shows several general and specific similarities, thus the velocity maps offer a
valuable additional constraint on models.
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