Multi-scale probability distributions of solar wind speed fluctuations at 1 AU described by a generalized Tsallis distribution



[1] The probability distributions of changes in the solar speed observed at 1 AU by ACE during 1999 on scales from 1 hour to 171 days and at a scale of 64 sec can be described by a single distribution function. The function is a simple generalization of the Tsallis q-distribution, a probability distribution that was derived from nonextensive statistical mechanics. The fluctuations in speed are related to (1) intermittent turbulence and shocks on the smallest scales; (2) ejecta, corotating streams, slow flows, interaction regions, etc. on intermediate scales; and (3) systems of interacting flows involving all of these features, on scales greater than the solar rotation period.