Newly identified properties of surface acoustic power
arXiv:0911.3042 · doi:10.1007/s11207-010-9550-3
Abstract
The cause of enhanced acoustic power surrounding active regions, the acoustic halo, is not as yet understood. We explore the properties of the enhanced acoustic power observed near disk center from 21 to 27 January 2002, including AR 9787. We find that (i) there exists a strong correlation of the enhanced high frequency power with magnetic-field inclination, with greater power in more horizontal fields, (ii) the frequency of the maximum enhancement increases along with magnetic field strength, and (iii) the oscillations contributing to the halos show modal ridges which are shifted to higher wavenumber at constant frequency in comparison to the ridges of modes in the quiet-Sun.
16 pages, 10 figures, submitted to solar physics
References in corpus (8)
- Helioseismology of Sunspots: A Case Study of NOAA Region 9787
- Helioseismology of Sunspots: Confronting Observations with Three-Dimensional MHD Simulations of Wave Propagation
- Comparing magnetic field extrapolations with measurements of magnetic loops
- Seismic Halos Around Active Regions: An MHD Theory
- Sunspot seismic halos generated by fast MHD wave refraction
- Signatures of Emerging Subsurface Structures in Acoustic Power Maps
- A Wave Scattering Theory of Solar Seismic Power Haloes
- Evidence of increasing acoustic emissivity at high frequency with solar cycle 23 in Sun-as-a-star observations
Cited by in corpus (14)
- Modeling the Subsurface Structure of Sunspots
- Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
- Properties of high-frequency wave power halos around active regions: an analysis of multi-height data from HMI and AIA onboard SDO
- Three-minute wave enhancement in the solar photosphere
- Magnetohydrodynamic waves driven by p-modes
- 3D simulations of realistic power halos in magneto-hydrostatic sunspot atmospheres: linking theory and observation
- Two-Dimensional Helioseismic Power, Phase, and Coherence Spectra of {\it Solar Dynamics Observatory} Photospheric and Chromospheric Observables
- Analysis of Helioseismic Power-Spectrum Diagram of A Sunspot
- Statistical analysis of acoustic wave parameters near active regions
- A study of the propagation of magnetoacoustic waves in small-scale magnetic fields using solar photospheric and chromospheric Dopplergrams: HMI/SDO and MAST observations
- Enhanced Acoustic Emission in Relation to the Acoustic Halo Surrounding Active Region 11429
- Statistical analysis of acoustic wave power and flows around solar active regions
- A Study of Acoustic Halos in Active Region NOAA 11330 using Multi-Height SDO Observations
- Enhanced sources of acoustic power surrounding AR11429