title: Magnetospheric Multiscale Observations of the Electron Diffusion Region of Large Guide Field Magnetic Reconnection.
abstract: 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.
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: S
authors.initials: S
authors.lastname: Eriksson
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: F D
authors.initials: FD
authors.lastname: Wilder
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.|Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Ergun
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.|The Blackett Laboratory, Imperial College, London SW7 2AZ, United Kingdom.
authors.forename: S J
authors.initials: SJ
authors.lastname: Schwartz
authors.affiliation: West Virginia University, Morgantown, West Virginia 26506, USA.
authors.forename: P A
authors.initials: PA
authors.lastname: Cassak
authors.affiliation: Southwest Research Institute, San Antonio, Texas 78238-5166, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Burch
authors.affiliation: University of Maryland, College Park, Maryland 20742, USA.
authors.forename: L-J
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Southwest Research Institute, San Antonio, Texas 78238-5166, USA.|University of New Hampshire, Durham, New Hampshire 03824, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Torbert
authors.affiliation: Space Sciences Laboratory, University of California, Berkeley, California 94720, USA.
authors.forename: T D
authors.initials: TD
authors.lastname: Phan
authors.affiliation: Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, 31028 Toulouse, France.|Centre National de la Recherche Scientifique, UMR 5277, Toulouse, France.
authors.forename: B
authors.initials: B
authors.lastname: Lavraud
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.|Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Goodrich
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.|Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Holmes
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.|Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Stawarz
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.|Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Sturner
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Malaspina
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Usanova
authors.affiliation: Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80303, USA.
authors.forename: K J
authors.initials: KJ
authors.lastname: Trattner
authors.affiliation: University of California, Los Angeles, Los Angeles, California 90095, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Strangeway
authors.affiliation: University of California, Los Angeles, Los Angeles, California 90095, USA.
authors.forename: C T
authors.initials: CT
authors.lastname: Russell
authors.affiliation: NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
authors.forename: C J
authors.initials: CJ
authors.lastname: Pollock
authors.affiliation: NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
authors.forename: B L
authors.initials: BL
authors.lastname: Giles
authors.affiliation: NASA, Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hesse
authors.affiliation: KTH Royal Institute of Technology, SE-11428 Stockholm, Sweden.
authors.forename: P-A
authors.initials: PA
authors.lastname: Lindqvist
authors.affiliation: University of Maryland, College Park, Maryland 20742, USA.
authors.forename: J F
authors.initials: JF
authors.lastname: Drake
authors.affiliation: University of Delaware, Newark, Delaware 19716, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: Shay
authors.affiliation: Space Research Institute, Austrian Academy of Sciences, 8042 Graz, Austria.
authors.forename: R
authors.initials: R
authors.lastname: Nakamura
authors.affiliation: KTH Royal Institute of Technology, SE-11428 Stockholm, Sweden.
authors.forename: G T
authors.initials: GT
authors.lastname: Marklund