Magnetospheric Multiscale Dayside Reconnection Electron Diffusion Region Events

Abstract

We have used the high-resolution data of the Magnetospheric Multiscale (MMS) mission dayside phase to identify twenty-one previously unreported encounters with the electron diffusion region (EDR), as evidenced by electron agyrotropy, ion jet reversals, and j dot E greater than 0. Three of the new EDR encounters, which occurred within a one-minute-long interval on November 23rd, 2016, are analyzed in detail. These events, which resulted from a relatively low and oscillating magnetopause velocity, contained large electric fields (several tens to hundreds of milliVolts per meter), crescent-shaped electron velocity phase space densities, large currents (greater than 2 microAmperes per square meter), and Ohmic heating of the plasma (near or exceeding 10 nanoWatts per cubic meter). Because of the slow in-and-out motion of the magnetopause, two of these events show the unprecedented mixture of perpendicular and parallel crescents, indicating the first breaking and reconnecting of solar wind and magnetospheric field lines. An extended list of thirty-two EDR or near-EDR events is also included, and demonstrates a wide variety of observed plasma behavior inside and surrounding the reconnection site.

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Cited by in corpus (8)

• Non-Maxwellianity of electron distributions near Earth's magnetopause
• The structure of a perturbed magnetic reconnection electron diffusion region
• In situ spacecraft observations of a structured electron diffusion region during magnetopause reconnection
• On the origin of "patchy" energy conversion in electron diffusion regions
• Magnetic Flux Transport Identification of Active Reconnection: MMS Observations in Earth's Magnetosphere
• Multi-scale coupling during magnetopause reconnection: the interface between the electron and ion diffusion regions
• Spontaneously generated flux ropes in 3-D magnetic reconnection
• Incompressible Extended Magnetohydrodynamics Waves: Implications of Electron Inertia