A Twin-CME Scenario for Ground Level Enhancement Events

Li, G., R. Moore, R. A. Mewaldt, L. Zhao, and A. W. Labrador, A Twin-CME Scenario for Ground Level Enhancement Events, Space Sci. Rev., 171, 141-160 (2012) (ADS)

The cartoon

(click on the image for a larger version)

The most powerful SEP events, few in number, can be called GLEs, and may or may not require physics beyond that necessary for an ordinary solar particle event. This cartoon suggests a particular form of exceptionalism: two consecutive CMEs, arrange just so and with the second one overtaking the first, may overlap. Then if the first event can release plasma into the open field, if interchange reconnection can happen, and if these "seed particles" help the acceleration process, then one may get an exceptional event (a CME). That is, if the Earth is in the field of fire. The Archivist counts five consecutive "if"s, but that is OK: GLEs are so rare that only two of them happened in Cycle 24.

Date: 2019 December 12