We present results of a global survey of single-pixel intensity power spectra from a 12-hour time period on June 26 , 2013 in a 1600x1600 pixel region from five wavelength channels of the NASA 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 computed from these time series , and then study the spatial dependence of the model parameters .
Two models of the power spectra as a function of frequency , \nu , are considered : ( 1 ) a 3-parameter power-law + tail , A \nu ^ { - n } + C , model and ( 2 ) a power-law + tail model + a 3-parameter localized Gaussian , \alpha \exp ( - ( \ln ( \nu ) - \beta ) ^ { 2 } / ( 2 \delta ^ { 2 } ) , which models a periodicity .
In general , spectra are well-described by at least one of these two models for all pixel locations , with an average data/model correlation of 0.93 and a standard deviation of 0.1 .
The spatial distribution of best-fit parameter values for the models are shown to provide new and unique insights into turbulent , quiescent and periodic features in the EUV solar corona and upper photosphere .
Locations where the second model is significantly better than the first model correspond clearly and directly to different visible features in the AIA observations and reveal quasi-periodic 3- and 5-minute oscillations .
Other findings include : a method for parameterizing solar EUV observations at pixel-level resolution based on their power spectra ; 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 5-minute oscillations throughout the solar corona from 304 to 211 Å ; a global \sim 4.0 -minute oscillation in 1600 Å ; ‘ ‘ Coronal Bullseyes ’ ’ appearing as radially decaying periodicities over sunspot and sporadic foot-point regions ; and ‘ ‘ Penumbral Periodic Voids ’ ’ appearing as symmetrical rings around sunspots in 1600 and 1700 Å in which there is no statistically significant Gaussian ( periodic ) component in the spectra .