Princeton Center for Heliophysics Seminar

The solar corona is the hot and ionized outer atmosphere of the Sun.  It traces out the complex solar magnetic field and expands into interplanetary space as the supersonic solar wind.  In 1958, Eugene Parker theorized that the presence of a million-degree corona necessarily requires the outward acceleration of a wind.  However, despite many years of exploration of both phenomena, we still do not have a complete understanding of the processes that heat the coronal plasma to its bizarrely high temperatures.  In this talk, I will discuss some new observations and theoretical concepts that are helping us get closer to an answer to this infamous coronal heating problem.  We will begin by following the Parker Solar Probe mission along its recent forays inside the Sun's mysterious "Alfven surface." We will then take account of some new analysis of old data from the SOHO mission: ultraviolet emission lines that tell us even more about collisionless plasma physics in the corona.  Lastly, we will confront these new pieces of observational data with theoretical models of magnetohydrodynamic turbulence.  Such models are now being used as the basis for global simulations of the corona and solar wind, but there are still some major missing pieces.  We will conclude by surveying how future measurements of the "young" solar wind (from both telescopes and in-situ probes) will fill in those gaps and better constrain our theoretical flights of fancy.