Challenges in Characterizing the Dynamics of Coronal Mass Ejections

Thompson, Barbara

Challenges in Characterizing the Dynamics of Coronal Mass Ejections

Tuesday, 12 February 2019: 16:10

Fountain I/II (Westin Pasadena)

Barbara J Thompson¹, Phillip Hess², Christina Kay³, Ryun Young Kwon⁴, Paulett Creyke Liewer⁵, M. Leila Mays¹, Marilena Mierla⁶ and Shea A. Hess Webber⁷, (1)NASA/GSFC, Greenbelt, MD, United States, (2)George Mason University Fairfax, Fairfax, VA, United States, (3)Boston University, Boston, MA, United States, (4)George Mason University Fairfax, School of Physics, Astronomy and Computational Sciences, Fairfax, VA, United States, (5)Jet Propulsion Laboratory, Pasadena, CA, United States, (6)Institute of Geodynamics of the Romanian Academy, Bucharest, Romania, (7)Stanford University, Stanford, CA, United States

Abstract:

There are several challenges in characterizing the kinematic properties of energetic CMEs. Most rapidly-evolving eruptions are accompanied by changes in the surrounding corona. The larger the impact on the surrounding corona, the more difficult it is to separate the “main” CME from the CME-associated brightenings. Complicating the issue is the range of observed propagation properties: super-radial expansion, asymmetric expansion, non-radial propagation, and alterations in the direction of propagation. These properties can be a function of both the internal magnetic structure of the CME and the structure of the corona through which the CME is propagating. While the relative contribution of internal/external factors can be difficult to assess, it is of fundamental importance because it not only reveals the nature of CMEs but also CME-associated phenomena.

We will cover several methods that are useful in addressing the difficulties regarding the characterization of CME kinematics. These include image segmentation methods as well as forward models of CME topology. We will also discuss the need to fold these measurement ambiguities into predictions via ensemble modeling.