Authors: Jon A. Linker (Predictive Science Inc.), Ronald M. Caplan (Predictive Science Inc.), Cooper Downs (Predictive Science Inc.), James Turtle (Predictive Science Inc.), Emily Mason (Predictive Science Inc.), Miko Stulajter (Predictive Science Inc.), Lisa Upton (Southwest Research Institute), Bibhuti Kumar Jha (Southwest Research Institute), Raphael Attie (George Mason University), Charles Nickolos Arge (NASA Goddard Space Flight Center), Carl J. Henney (Air Force Research Laboratory)

The solar magnetic field plays a key role in solar and heliospheric physics. The field is most easily measured in the photosphere, from ground or space-based telescopes, and these measurements are the essential input for models of the solar corona and solar wind, in the form of full-Sun magnetic maps. As nearly all of these observations are along the Sun-Earth line, a full solar rotation (27 days) is required to completely view the solar surface. Standard observatory maps are constructed over the course of a rotation, so they contain data that is as much as 27 days old. Coronal magnetohydrodynamic (MHD) models are typically time-relaxed using boundary conditions derived from such a map, providing an approximate time-stationary description of the corona for a given time period. In reality, the Sun’s magnetic flux is always evolving, and these changes in the flux affect the structure and dynamics of the corona and heliosphere. Modeling the time evolution of the corona requires a description of the photospheric magnetic flux evolution. Assimilative Surface Flux transport (SFT) models can describe this evolution by incorporating known surface flows and processes, to produce a continuous approximation of the state of the surface field, as a sequence of maps. SFTs have a long history, but special considerations are required to create map sequences of sufficient fidelity to drive a time-dependent MHD model. In this presentation, we describe the use of the components of the Open-source Flux Transport (OFT) model to create suitable map sequences for near real time modeling of the solar corona. We illustrate this approach for the time period surrounding the April 8, 2024 total solar eclipse.

Research supported by NASA and NSF.