The MMS Dayside Magnetic Reconnection Locations During Phase 1 and Their Relation to the Predictions of the Maximum Magnetic Shear Model

Autor: Robert J. Strangeway, S. M. Petrinec, Stefan Eriksson, K. J. Trattner, Robert E. Ergun, James L. Burch, S. A. Fuselier, Lorenzo Trenchi, Frederick Wilder, Barry Mauk, R. G. Gomez, W. S. Lewis, Barbara L. Giles, Eric Grimes, Christopher T. Russell
Rok vydání: 2017
Předmět:
Zdroj: Journal of Geophysical Research: Space Physics. 122
ISSN: 2169-9402
2169-9380
DOI: 10.1002/2017ja024488
Popis: Several studies have validated the accuracy of the Maximum Magnetic Shear model to predict the location of the reconnection site at the dayside magnetopause. These studies found agreement between model and observations for 74% to 88% of events examined. It should be noted that, of the anomalous events that failed the prediction of the model, 72% shared a very specific parameter range. These events occurred around equinox for an IMF clock angle of about 240°. This study investigates if this remarkable grouping of events is also present in data from the recently launched MMS mission. The MMS magnetopause encounter data base from the first dayside phase of the mission includes about 4500 full and partial magnetopause crossings and FTEs. We use the known reconnection line signature of switching accelerated ion beams in the magnetopause boundary layer to identify encounters with the reconnection region and identify 302 events during phase 1a when the spacecraft are at reconnection sites. These confirmed reconnection locations are compared with the predicted location from the Maximum Magnetic Shear model and revealed an 80% agreement. The study also revealed the existence of anomalous cases as mentioned in an earlier study. The anomalies are concentrated for times around the equinoxes together with IMF clock angles around 140° and 240°. Another group of anomalies for the same clock angle ranges was found during December events.
Databáze: OpenAIRE
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