ROSES ID: NNH13ZDA001N Selection Year: 2013
Program Element: Solar Dynamics Observatory
Principal Investigator: David McKenzie
Affiliation(s): Montana State University-Bozeman
Project Member(s):
Longcope, Dana W. Co-I Montana State University
Reeves, Katharine K Co-I Smithsonian Astrophysical Observatory
Summary:
In the evolution of a coronal mass ejection (CME) and the associated solar flare, a current sheet connecting the CME to the post-eruption flare arcade is important as the location of magnetic reconnection and energy release for the flare. Numerous observations in white light, UV, EUV, and X-rays indicate the presence of heated plasmas surrounding/within the current sheets, while numerical models are beginning to reproduce the temperatures and general appearances in EUV and X-rays. Conditions in this region are key for controlling the reconnection (e.g., length scales, onset, time-varying rate of flux transfer). However, only recently have high-resolution observations become possible with the capability to scrutinize the conditions within the sheet area. The most recent data from space-based telescopes reveal an environment far more complex than the simple laminar current sheet envisioned in two-dimensional and 2.5-D models of reconnection. It is a regime of complicated flows, eddies, and oscillatory bulk motions, likely pervaded by MHD shocks. While some observed oscillations have been treated as magnetosonic waves the presence of vortical flows and eddies is a relatively new discovery and is much harder to understand in the framework of a low-beta magnetized plasma. Indeed, analysis demonstrates that the plasma beta is of order unity, so that gas pressure forces and magnetic tensions have significant, and important, interplay in this crucial region.Performance Year | Reference | Investigation Type | Actions |
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1 | Reeves, Katharine K.; Freed, Michael S.; McKenzie, Da... | not set |
Performance Year | Reference | Actions |
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1 | McKenzie, David Eugene; Freed, Michael; (2014), Empirica... | |
1 | Scott, Roger B.; Freed, Michael; McKenzie, David Euge... | |
1 | Reeves, K.; Hanneman, W.; Freed, M.; McKenzie, D. E.; (2014)... | |
1 | Freed, Michael; McKenzie, David Eugene; (2016), An Evalu... |