Newkirk, Gordon, Jr. and John Harvey, Coronal Polar Plumes, Sol. Phys., 3, 321-343 (1968) (ADS)
(click on the image for a larger version)
An early view of how to form a plume in a polar region of the Sun.
These are striking features, denser than the surrounding corona, and
collimated outward by a unipolar field.
Unlike the coronal streamers that feed the heliospheric current sheet, this
dense structure does not contain a consistent current sheet since it's
basically unipolar.
Over the years since this paper was written, it has become increasingly
clear that some streamer-like features are in the same category, ie are
essentially unipolar; these are now called "pseudo-streamers."
Neither this present cartoon nor any other later view seems to have shed
any light on the physics, except to note that the magnetic field is important.
Here the authors were happy with a potential-field extrapolation,
but they had a weird view of it: why are the rays so straight?
If the hexagons represent the network, where is the
klapotosphere?
An early view of how to form a plume in a polar region of the Sun. These are striking features, denser than the surrounding corona, and collimated outward by a unipolar field. Unlike the coronal streamers that feed the heliospheric current sheet, this dense structure does not contain a consistent current sheet since it's basically unipolar. Over the years since this paper was written, it has become increasingly clear that some streamer-like features are in the same category, ie are essentially unipolar; these are now called "pseudo-streamers." Neither this present cartoon nor any other later view seems to have shed any light on the physics, except to note that the magnetic field is important. Here the authors were happy with a potential-field extrapolation, but they had a weird view of it: why are the rays so straight? If the hexagons represent the network, where is the klapotosphere?