AWavelet-based method for multifractal analysis of rough surfaces : Applications to high-resolution satellite images of cloud structure

We apply the 2D wavelet transform modulus maxima (WTMM) method to highresolution LANDSAT satellite images of cloudy scenes. The computation of the and multifractal spectra of the radiance fields confirms the relevance of the multifractal description to account for the intermittent nature of marine stratocumulus clouds. This analysis reveals that with the available set of experimental data, there is no way to discriminate between various phenomenological cascade models recently proposed to account for intermittency and their log-normal approximations. We emphasize the log-normal random -cascade model on separable wavelet orthogonal basis introduced in (N. Decoster, S.G. Roux, A.Arneodo, Eur. Phys. J. B 15, 739(2000)), as a very attractive model (at least as compared to the models commonly used in the literature) of the cloud architecture. Finally, we comment on the multifractal properties of marine stratocumulus radiance fields comparatively to previous experimental analysis of velocity and temperature fluctuations in high Reynolds number turbulence.