Turbulence-Driven Coronal Heating and Improvements to Empirical Forecasting of the Solar Wind

TL;DR

This paper introduces two advanced solar wind prediction models that incorporate full magnetic field profiles and Alfvén wave effects, improving accuracy and providing tools for space weather forecasting.

Contribution

The paper presents a new Python-based forecasting code, TEMPEST, built upon the physics-calibrated ZEPHYR model, enhancing solar wind prediction capabilities.

Findings

Both models reproduce the anticorrelation between wind speed and flux tube expansion.

TEMPEST shows less spread in results compared to traditional methods.

The models can validate magnetic field and solar wind relations for improved forecasting.

Abstract

Forecasting models of the solar wind often rely on simple parameterizations of the magnetic field that ignore the effects of the full magnetic field geometry. In this paper, we present the results of two solar wind prediction models that consider the full magnetic field profile and include the effects of Alfv\'en waves on coronal heating and wind acceleration. The one-dimensional MHD code ZEPHYR self-consistently finds solar wind solutions without the need for empirical heating functions. Another 1D code, introduced in this paper (The Efficient Modified-Parker-Equation-Solving Tool, TEMPEST), can act as a smaller, stand-alone code for use in forecasting pipelines. TEMPEST is written in Python and will become a publicly available library of functions that is easy to adapt and expand. We discuss important relations between the magnetic field profile and properties of the solar wind that can be used to independently validate prediction models. ZEPHYR provides the foundation and calibration for TEMPEST, and ultimately we will use these models to predict observations and explain space weather created by the bulk solar wind. We are able to reproduce with both models the general anticorrelation seen in comparisons of observed wind speed at 1 AU and the flux tube expansion factor. There is significantly less spread than comparing the results of the two models than between ZEPHYR and a traditional flux tube expansion relation. We suggest that the new code, TEMPEST, will become a valuable tool in the forecasting of space weather.