Solar wind mhd turbulence: Energy cascade, intermittency and dissipation

The aim of this paper is to address both questions of turbulence and dissipation in the solar wind. After a brief introduction of the solar wind plasma through some in-situ observations, and the basics of MHD turbulence, I will discuss a few problems of solar wind turbulence that still remain a puzzle: the nature of the nonlinear energy cascade, and the strong intermittent character of solar wind fluctuations in the inertial range, as well as the nature of the fluctuations in the dissipation range, which is crucial to understand the dissipation mechanisms of solar wind turbulence.