A Global Survey of EUV Corona Power Spectra
arXiv:1707.02448 · doi:10.1007/s11207-019-1399-5
Abstract
We present results of a global survey of single-pixel intensity power spectra from a 12-hour time period on 26 June 2013 in a 1600x1600 pixel region from four channels of the Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) instrument. We extract single-pixel time series from a derotated image sequence, fit models to the power spectra of these time series, and study the spatial dependence of the model parameters. Two power spectra models are considered: i) a three-parameter power-law + tail model and ii) a power-law + tail model + three-parameter localized Lorentzian, the latter to model periodicity. Spectra are well-described by at least one of these models for all pixel locations, with the spatial distribution of best-fit model parameters shown to provide new and unique insights into turbulent, quiescent and periodic features in the EUV corona and upper photosphere. Findings include: individual model parameters correspond clearly and directly to visible solar features; detection of numerous quasi-periodic three- and five-minute oscillations; observational identification of concentrated magnetic flux as regions of largest power-law indices [n]; identification of unique spectral features of coronal holes and filaments; identification of sporadic and pervasive five-minute oscillations throughout the corona; detection of the known global ~4.0-minute chromospheric oscillation; "coronal bullseyes" appearing as radially decaying periodicities over sunspots and sporadic foot-point regions; and "penumbral periodic voids" appearing as broad rings around sunspots in 1600 and 1700 Å in which spectra contain no statistically significant periodic component.
45 pages, 12 figures. Accepted for publication in Solar Physics
References in corpus (13)
- A Contemporary View of Coronal Heating
- Decayless low-amplitude kink oscillations: a common phenomenon in the solar corona?
- Coronal Heating, Weak MHD Turbulence and Scaling Laws
- Solar Atmospheric Oscillations and the Chromospheric Magnetic Topology
- On The Fourier And Wavelet Analysis Of Coronal Time Series
- Quasi-periodic pulsations in solar and stellar flares: re-evaluating their nature in the context of power-law flare Fourier spectra
- Turbulence in the sub-Alfvénic solar wind driven by reflection of low-frequency Alfvén waves
- Coronal Fourier power spectra: implications for coronal seismology and coronal heating
- Surface Magnetism Effects in Time-Distance Helioseismology
- A Coherence-Based Approach for Tracking Waves in the Solar Corona
- Thermal non-equilibriuem revealed by periodic pulses of random amplitudes in solar coronal loops
- Competition between shock and turbulent heating in coronal loop system
- Enhanced Acoustic Emission in Relation to the Acoustic Halo Surrounding Active Region 11429