Sonic and Alfvenic Critical Point and the Solar Probe Mission: presentation to the Solar Probe Science and Technology Definition Team

TL;DR

This paper discusses the significance of critical points in solar wind models for the Solar Probe Mission, concluding that while regions of transonic and trans-Alfvenic flow are physically interesting, the critical points themselves are less crucial.

Contribution

It clarifies the physical importance of critical points in solar wind models and their relevance to the Solar Probe Mission, emphasizing the focus on flow regions rather than mathematical critical points.

Findings

Regions of transonic and trans-Alfvenic flow are physically significant.

Mathematically defined critical points are less important than flow regions.

Critical points may be irregular and vary along the orbit.

Abstract

Are critical points important in the Solar Probe Mission? This is a brief discussion of the nature of critical points in solar wind models, what this means physically in the 'real' solar wind, and what can be expected along a nominal Solar Probe Orbit. The conclusion is that the regions where the wind becomes transonic and trans-Alfvenic, which may be irregular and varying, may reveal interesting physics, but the mathematically defined critical points themselves are of less importance.