EAGER: Developing an Ab initio Model of Coronal Mass Ejections (CMEs) Incorporating All Forms of Helicity

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This two-year EAGER project seeks to improve on the current coronal mass ejection (CME) models which assume a simplified structure of a simple, twisted rope-like structure. The structure assumed in current models is insufficient for capturing the full complexity of their evolution. This model will incorporate a more complex form of the the axis of this rope-like structure. This is important because actual observations of CMEs do not match with the simple model. Such a model has the potential to lead to a significantly improved prediction of the magnetic field direction when the CME hits Earth, a key problem for space weather forecasting.Specifically, this project is to develop a mathematical model for incorporating writhe into the current twisted flux-rope models. This will be used to examine how helicity is manifested in different forms in a CME, how it transforms from one form to another (from twist to writhe, for example), and how mechanisms such as reconnection with helmet streamers may be understood in terms of conservation of total helicity and changes in the dominant form of helicity within a CME. Such a new model will not only influence the analysis of in situ measurements of CMEs, but also change the way the entire geospace community approaches the CME initiation problem as well as the solar wind-magnetosphere coupling during CME-driven storms. This will also provide an insight into both the global and local structure of CMEs as they propagate. This model will be used to develop a reconstruction code and validate it using real CME observations (for example by DKIST) and in situ measurements.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.