Effects of expansion on solar wind turbulence

Author: Andrea Verdini

Affiliation:UPMC, LESIA and LPP

Magnetic fluctuations in the solar wind have power-law behaviour over approximately five decades in frequency. The common interpretation is that of a turbulent cascade: the energy residing in large-scale motions is transferred through a cascade towards small scales where it is finally dissipated. After introducing the basic concepts of turbulent cascade, I will revisit some observations and models, focusing on the contribution of the Italian community, to show that the above scenario is inadequate to describe the observed spectrum and the observed variability of spectral slopes. I will conclude by describing some recent works that try to include the effect of inhomogeneity to capture the nature of solar wind turbulence.