F. Lepreti et al., Multi-fractal structure of the dissipation field of intensity fluctuationsin the solar photosphere, PHYSICA A, 280(1-2), 2000, pp. 87-91
We investigate the scaling properties of the photospheric intensity field,
using images acquired at the THEMIS telescope with the Italian Panoramic Mo
nochromator. After calculating the power spectrum of the continuum intensit
y fluctuations, we analyze the scaling laws of the dissipation field obtain
ed from the intensity fluctuations, in analogy with the dissipation of pass
ive scalar fluctuations in turbulent fluids. Using the multifractal formali
sm, we show that the dissipation is intermittent and that it is characteriz
ed by stronger singularities in the higher photosphere than in the lower ph
otosphere. (C) 2000 Elsevier Science B.V. All rights reserved.