SHINE Postdoc: Modeling Elevated Charge States in Hot ICMEs and SEP Events to Study Their Inner Coronal Sources

Regents Of The University Of Michigan - Ann Arbor, Ann Arbor MI

Investigators

Abstract

The PI plans to model charge state evolution in the corona and compare the results with in-situ charge state observations from the Advanced Composition Explorer (ACE). She seeks to reconcile observations with models, building on methods and techniques developed by Laming (2004) at NRL, to enable the determination of thermal conditions on the Sun and acceleration mechanisms that produce the charge states observed in ICMEs (interplanetary manifestation of coronal mass ejections) and SEP (solar energetic particle) events. Her main objectives include the measurement and modeling of the charge states of various solar wind ions observed in hot ICMEs and SEPs in order to understand their origin and evolution, as well as to determine whether they arise from common sources on the Sun and how different expansion mechanisms affect their in-situ charge states. The PI asserts that the ionic composition of ICMEs and SEPs is a unique measure of the thermal environment of their coronal source regions. Charge states in the solar wind reflect the electron temperatures in the inner corona while SEPs additionally reflect the acceleration mechanisms that propel them out of the corona. This work will build upon previous efforts that have shown that ionic charge states of heliospheric plasmas are crucial in identifying ICMEs and analyzing the sources of energetic particles accelerated in the heliosphere. This proposed work will be the first ever attempt to model the ionic composition of hot ICMEs and SEP events. The results of this research will enable the modeling communities to validate models of the eruption of CMEs and the acceleration of solar energetic particles from the solar surface and in the heliosphere. Such improved models will assist space weather forecasting. All participants in the PI's planned collaborations have been actively involved in SHINE workshops and research activities.