Intermittent turbulence in the solar wind

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Abstract
This paper demonstrates the existence of intermittent turbulence in the solar wind at 8.5 AU. The pth‐order velocity structure functions show scaling behavior in the range of periods from 0.85 hour to 13.6 hours for p ≤ 20. The exponent of the scaling law s(p) is a quadratic function of p. Our observations of s(p) for compressible MHD turbulence on a scale of the order of ∼1 AU = 1.5×108 km are consistent with laboratory measurements of s(p) for gasdynamic turbulence on a scale of the order of 1 m, indicating the universal character of intermittent turbulence. The observations are not described by the “constant β” model of intermittent turbulence. They are marginally consistent with the lognormal model. The observations are consistent with a random β model prediction which assumes that the turbulence is a mixture of sheets and space‐filling eddies.