Direct evidence of multifractal atmospheric cascades from planetary scales down to 1 km.

We use 909 satellite images spanning the scale range 1-5000 km at both visible and infrared wavelengths to show that the variability at all observed scales and at all levels of intensity is very close to that predicted for a direct multiplicative scale invariant cascade starting at planetary scales. To within 1.6%/octave in scale, the observed type of (multi)scaling is very close to that theoretically predicted for universal multifractals, including multifractal phase transitions. Because of the strong vertical stratification, the scaling cannot be isotropic; these findings thus give strong support to the anisotropic "unified scaling" model of atmospheric dynamics.