  We investigate the scaling properties of the long-range temporal evolution
and intermittency of SDO/AIA intensity observations in four solar environments:
an active region core, a weak emission region, and two core loops. We use two
approaches: the probability distribution function (PDF) of time series
increments, and multifractal detrended fluctuation analysis (MF-DFA). Noise
taints the results, so we focus on the 171 Angstrom waveband , which has the
highest signal-to-noise ratio. The lags between pairs of wavebands distinguish
between coronal versus transition region (TR) emission. In all physical regions
studied, scaling in the range 15-45 min is multifractal, and the time series
are anti-persistent on the average. The degree of anti-correlation in the TR
time series is greater than for coronal emission. The multifractality stems
from long term correlations in the data rather than the wide distribution of
intensities. Observations in the 335 Angstrom waveband can be described in
terms of a multifractal with added noise. The multiscaling of the EUV data
agrees qualitatively with the radiance from a phenomenological model of
impulsive bursts plus noise, and also from ohmic dissipation in a reduced
magnetohydrodynamics (RMHD) model for coronal loop heating. The parameter space
must be further explored to seek quantitative agreement. Thus, the
observational signatures obtained by the combined tests of the PDF of
increments and the MF-DFA offer strong constraints which can systematically
discriminate among models for coronal heating.
