“…Turbulence in space plasma has been most extensively studied in the solar wind, but the power spectra of the magnetic or velocity field fluctuations could be investigated only in the frequency domain, since the spacecraft have made one-or at best two-point measurements (Scarf et al 1981, Mellott 1986, Moustaizis et al 1986, Clasßen et al 1999, Bavassano Cattaneo et al 2000, Borovsky et al 2003. Earlier observations have already shown that power spectra of the magnetic or velocity fields often contained an inertial range with a slope of approximately -5/3 (Coleman 1966(Coleman , 1967(Coleman , 1968, and also different slopes depending on frequency scale: -1/3, -1, and -5/3 (Goldstein and Roberts 1999).…”