Interferometric identification of ion acoustic broadband waves in the auroral region: CLUSTER observations - INSU - Institut national des sciences de l'Univers Access content directly
Journal Articles Geophysical Research Letters Year : 2005

Interferometric identification of ion acoustic broadband waves in the auroral region: CLUSTER observations

Abstract

We determine the phase velocity and k vector for parallel and oblique broadband extremely low frequency, ELF, waves on nightside auroral magnetic field lines at altitudes around 4.6 R E. We use internal burst mode data from the EFW electric field and wave instrument onboard the Cluster spacecraft to retrieve phase differences between the four probes of the instrument. The retrieved characteristic phase velocity is of the order of the ion acoustic speed and larger than the thermal velocity of the protons. The typical wavelength obtained from interferometry is around the proton gyro radius and always larger than the Debye length. We find that in regions with essentially no suprathermal electrons above a few tens of eV the observed broadband waves above the proton gyro frequency are consistent with upgoing ion acoustic and oblique ion acoustic waves.
Fichier principal
Vignette du fichier
Backrud_et_al-2005-Geophysical_Research_Letters.pdf (327.02 Ko) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

insu-01556705 , version 1 (05-07-2017)

Identifiers

Cite

M. Backrud, A. Tjulin, A. Vaivads, M. André, A. Fazakerley. Interferometric identification of ion acoustic broadband waves in the auroral region: CLUSTER observations. Geophysical Research Letters, 2005, 32 (21), pp.L21109. ⟨10.1029/2005GL022640⟩. ⟨insu-01556705⟩
46 View
131 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More