The Fast Auroral SnapshoT (FAST) Mission
TLDR
The FAST satellite mission as discussed by the authors investigates plasma processes occurring in the low altitude auroral acceleration region, where magnetic field-aligned currents couple global magnetospheric current systems to the high latitude ionosphere.Abstract:
The FAST satellite mission investigates plasma processes occurring in the low altitude auroral acceleration region, where magnetic field-aligned currents couple global magnetospheric current systems to the high latitude ionosphere. In the transition region between the hot tenuous magnetospheric plasma and the cold, dense ionosphere, these currents give rise to parallel electric fields, particle beams, plasma heating, and a host of wave-particle interactions. FAST instruments provide observations of plasma particles and fields in this region, with excellent temporal and spatial resolution combined with high quantitative accuracy. The spacecraft data system performs on-board evaluation of the measurements to select data “snapshots” that are stored for later transmission to the ground. New measurements from FAST show that upward and downward current regions in the auroral zone have complementary field and particle features defined by upward and downward directed parallel electric field structures and corresponding electron and ion beams. Direct measurements of wave particle interactions have led to several discoveries, including Debye-scale electric solitary waves associated with the acceleration of upgoing electron beams and ion heating, and the identification of electrons modulated by ion cyclotron waves as the source of flickering aurora. Detailed quantitative measurements of plasma density, plasma waves, and electron distributions associated with auroral kilometric radiation source regions yield a consistent explanation for AKR wave generation.read more
Citations
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Journal ArticleDOI
Solar Wind Electrons Alphas and Protons (SWEAP) Investigation: Design of the Solar Wind and Coronal Plasma Instrument Suite for Solar Probe Plus
Justin C. Kasper,Justin C. Kasper,R. Abiad,Gerry Austin,Marianne Balat-Pichelin,Stuart D. Bale,John W. Belcher,Peter Berg,Henry Bergner,Matthieu Berthomier,Jay Bookbinder,Etienne Brodu,David Caldwell,Anthony W. Case,Benjamin D. G. Chandran,Peter Cheimets,Jonathan Cirtain,Steven R. Cranmer,D. W. Curtis,Peter Daigneau,Greg Dalton,Brahmananda Dasgupta,David DeTomaso,M. Diaz-Aguado,Blagoje Djordjevic,Bill Donaskowski,Michael Effinger,Vladimir Florinski,N. J. Fox,Mark D. Freeman,Dennis L. Gallagher,S. Peter Gary,T. Gauron,Richard Gates,M. L. Goldstein,Leon Golub,D. Gordon,R. S. Gurnee,Giora Guth,Jasper Halekas,Ken Hatch,Jacob Heerikuisen,George C. Ho,Qiang Hu,Greg Johnson,Steven P. Jordan,Kelly E. Korreck,Davin Larson,Alan J. Lazarus,Gang Li,Roberto Livi,Michael Ludlam,Milan Maksimovic,James P. McFadden,William Marchant,B. Maruca,David J. McComas,David J. McComas,Luciana Messina,Tony Mercer,Sang Park,Andrew M. Peddie,Nikolai V. Pogorelov,Matthew J. Reinhart,John D. Richardson,M. S. Robinson,Irene Rosen,Ruth M. Skoug,Amanda Slagle,John T. Steinberg,Michael L. Stevens,Adam Szabo,E. Taylor,Chris Tiu,Paul Turin,Marco Velli,G. M. Webb,Phyllis Whittlesey,K. H. Wright,S. T. Wu,Gary P. Zank +80 more
TL;DR: The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on Solar Probe Plus is a four sensor instrument suite that provides complete measurements of the electrons and ionized helium and hydrogen that constitute the bulk of solar wind and coronal plasma.
Journal ArticleDOI
Evidence for kinetic Alfvén waves and parallel electron energization at 4-6 RE altitudes in the plasma sheet boundary layer
John R. Wygant,A. Keiling,Cynthia A Cattell,Robert L. Lysak,M. Temerin,F. S. Mozer,Craig Kletzing,J. D. Scudder,V. Streltsov,William Lotko,Christopher T. Russell +10 more
TL;DR: In this paper, it was shown that the smaller-scale kinetic Alfven waves have durations in the spacecraft frame of 250 ms to 1 s (but may have shorter time durations since the Nyquist frequency of the magnetic field experiment is � 4 Hz.).
Journal ArticleDOI
Polar spacecraft based comparisons of intense electric fields and Poynting flux near and within the plasma sheet-tail lobe boundary to UVI images: An energy source for the aurora
John R. Wygant,A. Keiling,Cynthia A Cattell,M. Johnson,Robert L. Lysak,M. Temerin,F. S. Mozer,Craig Kletzing,J. D. Scudder,W. K. Peterson,Christopher T. Russell,George K. Parks,Mitchell J. Brittnacher,James F. Spann +13 more
TL;DR: In this article, the Poynting flux associated with the perturbation fields measured at these altitudes is about 1-2 ergs per square centimeters per second and is directed along the average magnetic field direction toward the ionosphere.
Journal ArticleDOI
Factors controlling ionospheric outflows as observed at intermediate altitudes
TL;DR: In this paper, two primary sources of ion outflows are considered: ion heating through dissipation of downward Poynting flux and electron heating through soft electron precipitation, and the data were restricted to dayside magnetic local times.
Journal ArticleDOI
Variations in the polar cap area during two substorm cycles
Steve Milan,Mark Lester,Stanley W. H. Cowley,Kjellmar Oksavik,Mitchell J. Brittnacher,R. A. Greenwald,George J. Sofko,Jean-Paul Villain +7 more
TL;DR: In this article, the authors employed observations from several sources to determine the location of the polar cap bound-ary, or open/closed field line boundary, at all local times, allowing the amount of open flux in the magnetosphere to be quantified.
References
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Journal ArticleDOI
Large‐scale characteristics of field‐aligned currents associated with substorms
T. Iijima,T. A. Potemra +1 more
TL;DR: In this paper, the authors determined the statistical features of field-aligned currents during a large number of substorms from the magnetic field observations acquired with the Triad satellite, including the following: (1) the large-scale regions of fieldaligned currents determined previously by the authors (Iijima and Potemra, 1976a) persist during all phases of sub-storm activity, namely, region 1, located near the poleward boundary of the fieldaligned current region, and region 2, positioned near the equatorward boundary.
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FAST satellite observations of large‐amplitude solitary structures
Robert E. Ergun,C. W. Carlson,James P. McFadden,F. S. Mozer,Gregory T. Delory,W. J. Peria,C. C. Chaston,M. Temerin,Ilan Roth,L. Muschietti,R. C. Elphic,Robert J. Strangeway,Robert F. Pfaff,Cynthia A Cattell,David Klumpar,E. G. Shelley,W. K. Peterson,E. Moebius,L. M. Kistler +18 more
TL;DR: In this paper, the authors report observations of fast solitary waves that are ubiquitous in downward current regions of the mid-altitude auroral zone and propose that these nonlinear structures play a key role in supporting parallel electric fields.
Journal ArticleDOI
FAST observations in the downward auroral current region: Energetic upgoing electron beams, parallel potential drops, and ion heating
C. W. Carlson,James P. McFadden,Robert E. Ergun,M. Temerin,W. J. Peria,F. S. Mozer,David Klumpar,E. G. Shelley,W. K. Peterson,E. Moebius,R. C. Elphic,Robert J. Strangeway,Cynthia A Cattell,Robert F. Pfaff +13 more
TL;DR: In this article, the acceleration of upgoing electron beams by quasi-static parallel electric fields was detected in the winter auroral zone, and the most energetic ion conics were found coincident with these beams, in agreement with the model for trapped conics.
Journal ArticleDOI
FAST satellite observations of electric field structures in the auroral zone
Robert E. Ergun,C. W. Carlson,James P. McFadden,F. S. Mozer,Gregory T. Delory,W. J. Peria,C. C. Chaston,M. Temerin,R. C. Elphic,Robert J. Strangeway,Robert F. Pfaff,Cynthia A Cattell,David Klumpar,E. G. Shelley,W. K. Peterson,E. Moebius,L. M. Kistler +16 more
TL;DR: In this article, the authors demonstrate that parallel electric fields may be a fundamental particle acceleration mechanism in astrophysical plasmas by comparing the inferred parallel potentials of electrostatic shocks with particle energies.
Journal ArticleDOI
Vlf hiss and related plasma observations in the polar magnetosphere.
D. A. Gurnett,L. A. Frank +1 more
TL;DR: In this paper, a study of auroral-zone vlf hiss and low-energy charged-particle observations with the Injun 5 satellite is presented, and the results of this study provide a direct verification of the association between auroral zone vlfHiss and intense fluxes of low energy electrons with energies on the order of 100 eV to several keV.