Cristin-resultat-ID: 1496436
Sist endret: 21. januar 2018, 21:11
NVI-rapporteringsår: 2017
Resultat
Vitenskapelig artikkel
2017

Equatorward propagating auroral arcs driven by ULF wave activity: Multipoint ground- and space-based observations in the dusk sector auroral oval

Bidragsytere:
  • Lisa Baddeley
  • Dag Arne Lorentzen
  • Noora Partamies
  • M. Denig
  • Viacheslav A. Pilipenko
  • Kjellmar Oksavik
  • mfl.

Tidsskrift

Journal of Geophysical Research (JGR): Space Physics
ISSN 2169-9380
e-ISSN 2169-9402
NVI-nivå 2

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2017
Publisert online: 2017
Trykket: 2017
Volum: 122
Hefte: 5
Sider: 5591 - 5605

Importkilder

Scopus-ID: 2-s2.0-85019158503

Beskrivelse Beskrivelse

Tittel

Equatorward propagating auroral arcs driven by ULF wave activity: Multipoint ground- and space-based observations in the dusk sector auroral oval

Sammendrag

Observations of multiple equatorward propagating arcs driven by a resonant Alfvén wave on closed field lines are presented. Data sets from the European Incoherent Scatter Svalbard Radar (ESR) and Meridian Scanning Photometer in Longyearbyen, All-Sky Camera in Ny Ålesund, ground magnetometer data in Svalbard, and Defense Meteorological Satellite Program (DMSP) F16 satellite were utilized to study the arc structures. The arcs had an equatorward phase propagation of ~0.46 km s−1 and were observed in the dusk ionosphere from 1800 to 2030 magnetic local time. Analysis of the optical data indicates that the Alfvén wave had a frequency of 1.63 mHz and an azimuthal wave number, m ~ −20 (the negative sign indicating a westward propagation). Inverted-V electron populations associated with field-aligned currents of between 0.5 and 0.8 μA m−2 are observed by DMSP F16 inside the arc structures. In addition to electron density enhancements associated with the arcs, the ESR data show elevated ion temperatures in between the arcs consistent with electric field enhancements and ionospheric heating effects. The combination of ESR and DMSP F16 data indicates that the wave energy was dissipated through ionospheric Joule and/or ion frictional heating and acceleration of particles into the ionosphere, generating the auroral displays. The fine-scale structuring, in addition to the propagation direction and scale size, would suggest that the auroral features are the signatures of a field line resonance driven by an interaction with a compressional fast mode wave propagating earthward from the magnetotail.

Bidragsytere

Aktiv cristin-person

Lisa Baddeley

  • Tilknyttet:
    Forfatter
    ved British Antarctic Survey
  • Tilknyttet:
    Forfatter
    ved Avdeling for arktisk geofysikk ved Universitetssenteret på Svalbard

Dag Arne Lorentzen

  • Tilknyttet:
    Forfatter
    ved Avdeling for arktisk geofysikk ved Universitetssenteret på Svalbard
  • Tilknyttet:
    Forfatter
    ved British Antarctic Survey

Noora Partamies

  • Tilknyttet:
    Forfatter
    ved Institutt for fysikk og teknologi ved Universitetet i Bergen
  • Tilknyttet:
    Forfatter
    ved Avdeling for arktisk geofysikk ved Universitetssenteret på Svalbard

M. Denig

  • Tilknyttet:
    Forfatter
    ved National Oceanic and Atmospheric Administration

Viacheslav A. Pilipenko

  • Tilknyttet:
    Forfatter
    ved Russian Academy of Sciences
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