Astronomy and Astrophysics – Astronomy
Scientific paper
Jun 2010
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2010aspc..428...87r&link_type=abstract
SOHO-23: Understanding a Peculiar Solar Minimum ASP Conference Series Vol. 428, proceedings of a workshop held 21-25 September 2
Astronomy and Astrophysics
Astronomy
Scientific paper
The Cycle 23-Cycle 24 minimum was deep and prolonged, similar to minima of the late 19th and early 20th centuries but quite different from those between the overlapping cycles of the early space age. This provides a unique opportunity to study the Sun at very low levels of magnetic activity. Here we examine the quiet Sun, defining it to be those portions of the Sun for which continuum intensity variations are dominated by thermal perturbations as opposed to opacity fluctuations due to the presence of magnetic fields. We briefly present evidence that: (1) The expected thermal signature of the solar supergranulation can not be separated from magnetic contributions without masking the contribution of at least 95% of the pixels. By this measure, at most 5% of the Sun is truly quiet. (2) There was a rapid decay of active network magnetic fields entering this solar minimum, a consequent increase in the internetwork area, but a nearly constant fractional area covered by network fields. This suggests the continuous fragmentation and decay of active region fields into weaker field components, but also, possibly, an underlying continuous flux concentration mechanism maintaining the network field. (3) One of the first flux emergence episodes of Cycle 24 did not occur as a coherent active region, but instead in the form of disorganized spatially-dispersed small-scale magnetic elements. Under the paradigm of a deep-rooted dynamo, this suggests an episode of incoherent field loss from the generation region or a failed/shredded omega loop rise through the convection zone.
No associations
LandOfFree
Is There Such a Thing as Quiet Sun? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Is There Such a Thing as Quiet Sun?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Is There Such a Thing as Quiet Sun? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-835503