Basic topology of twisted magnetic configurations in solar flares
Titov, V. S. and P. Démoulin, Basic topology of twisted magnetic configurations in solar flares, A&A, 351, 707-720 (1999) (ADS)
(click on the image for a larger version)
From a very influential paper, this is a representation of the
geometry involving a "bald patch", ie a region in which the magnetic
field is concave upwards at the polarity inversion line in the photosphere.
This may not be the best representation of this, but it looks
very attractive.
A flux rope whose axis rises above the photosphere will result in such a
thing; otherwise there might just be the appearance of sheared field.
From a very influential paper, this is a representation of the geometry involving a "bald patch", ie a region in which the magnetic field is concave upwards at the polarity inversion line in the photosphere. This may not be the best representation of this, but it looks very attractive. A flux rope whose axis rises above the photosphere will result in such a thing; otherwise there might just be the appearance of sheared field.