J. C. Holmes

Magnetospheric Multiscale Observations of the Electron Diffusion Region of Large Guide Field Magnetic Reconnection

We report observations from the Magnetospheric Multiscale (MMS) satellites of a large guide field magnetic reconnection event. The observations suggest that two of the four MMS spacecraft sampled the electron diffusion region, whereas the other two spacecraft detected the exhaust jet from the event. The guide magnetic field amplitude is approximately 4 times that of the reconnecting field. The event is accompanied by a significant parallel electric field (E_{∥}) that is larger than predicted by simulations. The high-speed (∼300  km/s) crossing of the electron diffusion region limited the data set to one complete electron distribution inside of the electron diffusion region, which shows significant parallel heating. The data suggest that E_{∥} is balanced by a combination of electron inertia and a parallel gradient of the gyrotropic electron pressure.

Magnetospheric Multiscale Satellites Observations of Parallel Electric Fields Associated with Magnetic Reconnection.

We report observations from the Magnetospheric Multiscale satellites of parallel electric fields (E_{∥}) associated with magnetic reconnection in the subsolar region of the Earths magnetopause. E_{∥} events near the electron diffusion region have amplitudes on the order of 100  mV/m, which are significantly larger than those predicted for an antiparallel reconnection electric field. This Letter addresses specific types of E_{∥} events, which appear as large-amplitude, near unipolar spikes that are associated with tangled, reconnected magnetic fields. These E_{∥} events are primarily in or near a current layer near the separatrix and are interpreted to be double layers that may be responsible for secondary reconnection in tangled magnetic fields or flux ropes. These results are telling of the three-dimensional nature of magnetopause reconnection and indicate that magnetopause reconnection may be often patchy and/or drive turbulence along the separatrix that results in flux ropes and/or tangled magnetic fields.

Magnetospheric Multiscale observations of large-amplitude, parallel, electrostatic waves associated with magnetic reconnection at the magnetopause

We report observations from the Magnetospheric Multiscale satellites of large-amplitude, parallel, electrostatic waves associated with magnetic reconnection at the Earths magnetopause. The observe ...

MMS Multipoint electric field observations of small-scale magnetic holes

Small-scale magnetic holes (MHs), local depletions in magnetic field strength, have been observed multiple times in the Earths magnetosphere in the bursty bulk flow (BBF) braking region. This part ...

Drift waves, intense parallel electric fields, and turbulence associated with asymmetric magnetic reconnection at the magnetopause

Observations of magnetic reconnection at Earths magnetopause often display asymmetric structures that are accompanied by strong magnetic field (B) fluctuations and large-amplitude parallel electri ...

Observations of large‐amplitude, parallel, electrostatic waves associated with the Kelvin‐Helmholtz instability by the magnetospheric multiscale mission

On 8 September 2015, the four Magnetospheric Multiscale spacecraft encountered a Kelvin-Helmholtz unstable magnetopause near the dusk flank. The spacecraft observed periodic compressed current shee ...

Magnetic Reconnection, Turbulence, and Particle Acceleration: Observations in the Earth's Magnetotail

We report observations of turbulent dissipation and particle acceleration from large-amplitude electric fields (E) associated with strong magnetic field (B) fluctuations in the Earths plasma sheet ...