Features of the Active Evening Plasma Sheet from MMS

Abstract:

The Magnetospheric Multiscale (MMS) mission, consisting of four identical plasmas and fields observatories, was launched into a 12 R_E elliptical equatorial orbit in March 2015 and was in the process of being commissioned through August 2015. During commissioning, the orbit apogee rotated from near midnight through the evening toward the dusk sector and occasionally captured new observations of the plasma sheet, its boundary layers, and the magnetospheric tail lobes. On 22-23 June, an especially active plasma sheet was involved in a major geospace storm that developed a ring current with 200 nT D_ST. We report on the ion kinetic and flow features of this active plasma sheet, comparing them with familiar observations from earlier missions, as an exercise in validating the MMS observations and assessing their capabilities to provide higher time resolution in multi-point views of thin, fast-moving structures. The observed features include but are not limited to cold lobal wind streams in the lobes, tailward flowing auroral beams and conics, hot earthward field-aligned flows and counter-flows, fast cross-field convection of some flows toward the neutral sheet, and the hot isotropic plasma sheet proper. Relationships between these features, the ionosphere, and the reconnecting magnetotail will be explored and discussed, seeking preliminary conclusions.