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Webinar: The Nature of Streamer Blowout Coronal Mass Ejections
Wednesday, 05 September 2018, 4:00
Wednesday, September 5, 2018. 4:00PM Eastern. Webinar: The Nature of Streamer Blowout Coronal Mass Ejections. Angelos Vourlidas, JHUAPL. Sponsored by NCAR|UCAR. More information here.
Vourlidas investigates a particular class of coronal mass ejections (CMEs), named streamer-blowout CMEs (SBOs). The events are characterized by a gradual swelling of the overlying streamer, lasting hours to days, followed by a slow, wide CME, generally exhibiting a 3-part structure, which leaves the streamer significantly depleted in its wake. SBOs have a long history constituting the earliest detected CME type. however, they have not been studied in much detail as a distinct CME class. Most of the researcher’s understanding of their properties, origin, and solar cycle dependence were based on individual cases or small sample sizes. Vourlidas attempted to remedy this situation with a comprehensive study of LASCO observations across two solar cycles (1996-2015). Among the intriguing results of their study are: (1) that some events can take days to evacuate the corona challenging our conventional approach in defining CMEs, (2) that the locations of SBOs follow the tilt of the global dipole (but not from 2014 onwards---why?) and, (3) that they exhibit flux rope morphology at a much higher rate (61%) than regular CMEs (40%).
Vourlidas proposes that these characteristics are consistent with SBOs arising from extended polarity inversion lines outside active regions (e.g. quiet sun and polar crown filaments) through the release, via reconnection, of magnetic energy, likely accumulated via differential rotation.