Seismic diff. between solar magnetic cycles 23/24

Solar magnetic activity follows regular cycles of about 11 years with an inversion of polarity in the poles every ~22 years. This changing surface magnetism impacts the properties of the acoustic modes. The acoustic mode frequency shifts are a good proxy of the magnetic cycle. In this paper, we investigate solar magnetic activity cycles 23 and 24 through the evolution of the frequency shifts of low-degree modes (l= 0, 1, 2) in three frequency bands. These bands probe properties between 74 and 1575 km beneath the surface. The analysis is carried out by using observations from the space instrument Global Oscillations at Low Frequency and the ground-based Birmingham Solar Oscillations Network and Global Oscillation Network Group. The frequency shifts of radial modes suggest that changes in magnetic field amplitude and configuration are likely to occur near the Sun's surface rather than its core. The maximum shifts of solar cycle 24 occur earlier at mid and high latitudes compared to the equator, about 1550km beneath the photosphere. At this depth but near the equator, this maximum aligns with the surface activity but is stronger in magnitude. At around 74km deep, the behaviour near the equator mirrors the surface, while at higher latitudes, it matches the strength of cycle 23.

Identifier
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/A+A/691/L20
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/691/L20
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/691/L20
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/A+A/691/L20
Provenance
Creator Garcia R.A.; Breton S.N.; Salabert D.; Tripathy S.C.; Jain K.; Mathur S.,Panetier E.
Publisher CDS
Publication Year 2024
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysical Processes; Astrophysics and Astronomy; Natural Sciences; Physics; Solar System Astronomy; Stellar Astronomy