Princeton University Astrophysical Sciences Special Seminar

Convective motions on the solar surface launch Alfven waves that propagate out into the interplanetary medium. On their way, the waves become turbulent, and their energy cascades from large wavelengths to small wavelengths. At sufficiently small wavelengths, the fluctuations dissipate, heating the background plasma. This flow of energy from convective motions to individual particles in the solar-wind plasma is likely the key to the origin of the solar wind, one of the long-standing problems in heliospheric physics. In this talk, I will describe recent research on the different stages of this energy flow: the way that fluctuations evolve as they propagate out from the Sun, the different physical processes that govern the cascade of fluctuation energy to small scales, and the dissipation of small-scale fluctuations by stochastic ion heating. I will also discuss what the study of solar-wind turbulence has taught us about the solar wind's origin and fundamental plasma physics, as well as what it might yet teach us about other astrophysical outflows.