Characterizing Coronal Structure: Contextual Predictions For Parker Solar Probe From Global MHD Simulations With Dynamical Turbulence Modeling
Abstract
As the solar plasma flows out from the corona and transitions into the solar wind, it transforms from a magnetically structured, subsonic, and sub-Alfvénic regime into a supersonic and super-Alfvénic flow dominated by hydrodynamics. Recent analysis of remote imaging observations in solar minimum conditions by DeForest et al. (2016) has described the early stages of this transition, which may also coincide with the onset of large-scale turbulence in the solar wind. Here we extend this analysis to global magnetohydrodynamic simulation of the corona and solar wind based on inner boundary conditions that emulate solar minimum, in anticipation of the first phase of Parker Solar Probe (PSP) observations, which are expected during solar minimum as well. Taken together with the imaging analysis, the simulation results provide more detailed expectations for locations of the Alfvén critical surface and the first plasma beta unity surface moving from the corona into the dynamically active solar wind. The turbulence parameters computed from the simulations also enable estimations of the characteristic scales at which in-situ turbulence may influence the dynamics of the solar wind. Estimations of relevant parameters along a simulated PSP trajectory are presented. Issues pertaining to the use of Taylor's frozen-in hypothesis with PSP perihelion data are discussed.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E.628C