NEWS | July 16, 2012

NRL Leads NASA Team Workshop on Coronal Mass Ejection Initiation

By Donna McKinney

Dr. Mark Linton, a researcher in the Naval Research Laboratory's Space Science Division, recently convened a workshop exploring coronal mass ejections (CMEs). Dr. Linton is currently leading a NASA Living with a Star Targeted Research & Technology team that is tasked by NASA to study solar Coronal Mass Ejection initiation.

The team is tasked to carry out a four-year investigation of how changes in solar magnetic fields initiate solar CME eruptions. CMEs are a major driver of space weather, which can damage Navy space assets and radio communication and detection capabilities. Researchers seek to improve their understanding of how CMEs are initiated because it is of key importance for developing capabilities to predict space weather.

The team Dr. Linton is leading consists of CME initiation and magnetic flux experts from the NRL's Space Science Division; experts from Predictive Sciences, Inc. on the initiation and inter-planetary propagation of CMEs; experts from NASA's Goddard Space Flight Center on the analysis of photospheric magnetic field dynamics observed by the Helioseismic and Magnetic Imager on NASA's Solar Dynamics Observatory; and, experts from the National Oceanic and Atmospheric Administration and from the National Optical Astronomy Observatory on helioseismological measurements of magnetic activity signatures in the solar convection zone.

The CME Initiation Team workshop Dr. Linton convened on April 16th and 17th addressed the issue of how measurements of magnetic flux emergence could be used to motivate and to drive CME eruption modeling and simulation. This is a core issue for understanding CME initiation, since solar magnetic fields — which are the source of CME eruptions — are generated in the solar interior, rise up through the solar convection zone to the photosphere, and then emerge into the solar corona. Understanding CME initiation therefore requires an understanding of how solar magnetic fields emerge into and energize the solar corona.

At the April meeting, Dr. Linton explained, the team focused on two related topics. First: how can simulations of flux emergence be combined with helioseismic observations of the rise of magnetic fields through the convection zone to improve our understanding of how flux emergence occurs, and to improve our ability to predict flux emergence events? Second: how can photospheric observations of flux emergence and dynamics be incorporated into coronal CME initiation simulations to provide more realistic drivers for CME eruptions, towards accurate space weather prediction at Earth? With answers to these questions, researchers hope to be better able to understand and predict space weather.