MULTIFRACTAL STRUCTURE OF SPEED FLUCTUATIONS IN RECURRENT STREAMS AT 1-AU AND NEAR 6-AU

This paper demonstrates the existence of multifractal structure in the velocity fluctuations associated with recurrent streams at 1 AU and near 6 AU. There is a significant evolution of the multifractal spectrum from 1 AU to 6 AU. At 1 AU the fluctuations on all scales in the indicated range are related to the local speed gradients associated with the stream structure. Near 6 AU the multifractal structure of the speed fluctuations approaches the universal form for intermittent turbulence for moments q > 5, and it has approximately the value expected for a set of discontinuities for q = 2.