skip to main content

Title: Helioseismology of pre-emerging active regions. III. Statistical analysis

The subsurface properties of active regions (ARs) prior to their appearance at the solar surface may shed light on the process of AR formation. Helioseismic holography has been applied to samples taken from two populations of regions on the Sun (pre-emergence and without emergence), each sample having over 100 members, that were selected to minimize systematic bias, as described in Paper I. Paper II showed that there are statistically significant signatures in the average helioseismic properties that precede the formation of an AR. This paper describes a more detailed analysis of the samples of pre-emergence regions and regions without emergence based on discriminant analysis. The property that is best able to distinguish the populations is found to be the surface magnetic field, even a day before the emergence time. However, after accounting for the correlations between the surface field and the quantities derived from helioseismology, there is still evidence of a helioseismic precursor to AR emergence that is present for at least a day prior to emergence, although the analysis presented cannot definitively determine the subsurface properties prior to emergence due to the small sample sizes.
Authors:
; ;  [1] ;  [2]
  1. NorthWest Research Associates, 3380 Mitchell Lane, Boulder, CO 80301 (United States)
  2. Max-Planck-Institut für Sonnensystemforschung, Justus-von-Leibig-Weg 3, 37077 Göttingen, Germany. (Germany)
Publication Date:
OSTI Identifier:
22357038
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 786; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ACCOUNTING; CORRELATIONS; HOLOGRAPHY; MAGNETIC FIELDS; OSCILLATIONS; SUN; SURFACES; VISIBLE RADIATION