SPRG Seminars
August 8, 2012:
"Impact of observational uncertainties on universal scaling of MHD turbulence "
Bogdan Hnat, Center for Fusion Space and Astrophysics, Department of Physics, University of Warwick, UK
Quantifying the scaling of fluctuations in the solar wind is central to testing predictions of turbulence theories. We study spectral features of Alfvenic turbulence in fast solar wind and propose a general, instrument independent method to estimate the uncertainty in velocity fluctuations obtained by in-situ satellite observations. We show that when the measurement uncertainties of the velocity fluctuations are taken into account the less energetic Elsasser spectrum obeys a unique power law scaling throughout the inertial range as prevailing theories of magnetohydrodynamic turbulence predict. Moreover, in the solar wind interval analyzed, the two Elsasser spectra are observed to have the same scaling exponent z=-1.54 throughout the inertial range.