Implications of the S-Web for the Corona and Inner Heliosphere

Abstract:

Decades of satellite observations have shown that the solar wind that forms the heliosphere consists of two distinct types: the so-called fast and slow. The fast wind originates back at the Sun in long-lived open field regions observed as “coronal holes” in X-Ray images, but the source of the slow wind has long been an issue of intense debate. Due to its observed location in the heliosphere, its plasma composition, and its variability, many models for the origin of the slow wind postulate that it is a result of the release of closed-field plasma onto open field lines. In the recent S-Web model we proposed that the slow wind originates at a dynamic boundary region between open and closed flux in the solar corona. Consequently, the detailed structure of the open-closed magnetic boundary and, most important, the dynamics of this boundary are essential for determining the properties of the slow wind and of the heliosphere, in general. The three important magnetic topologies of the open-closed boundary in the corona and their consequences for the inner heliosphere will be discussed. Furthermore, recent simulations will be presented revealing the dynamics of this boundary and demonstrating that these dynamics can account for the observed properties of the slow wind. The implications of our results for understanding the corona-heliosphere connection and especially for interpreting observations from the upcoming Solar Orbiter and Solar Probe Plus missions will be discussed.

This work was supported by the NASA TR&T and SR&T Programs.