First direct optical observations of plasma flows using afterglow of O+O+ in discrete aurora
First direct optical observations of plasma flows using afterglow of O+O+ in discrete aurora
Imaging of active structured aurora in the forbidden O+ ion line at 732.0 nm provides a possibility of direct observation of plasma drifts in the topside ionosphere. The metastable O+ 2P state has a radiative lifetime of 5 s, so the oxygen ions can be detected after the precipitation creating them has ceased. The decay time of the O+ emission is studied and modelled with a time-dependent electron transport and ion chemistry model. Four examples are given of O+ afterglow observed with the multi-spectral imager, auroral structure and kinetics (ASK), which was located near Tromsø, Norway, in 2006. Estimates are given of drift velocities resulting from the analysis of the afterglow motions. Bulk plasma velocities of 340 and 720 m/s directed eastwards were found for two afterglowing arc filaments, corresponding to southward electric fields of 18 and 40 mV/m, respectively.
ionosphere, plasma drift, aurora, oxygen ion, electric fields
228-238
Dahlgren, H.
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Ivchenko, N.
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Lanchester, B.S.
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Ashrafi, M.
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Whiter, D.
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Marklund, G.
ca3a83f3-e335-4d69-b5e3-2dad226e339f
Sullivan, J.
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February 2009
Dahlgren, H.
8d021086-b328-46fd-affd-a7c8d2b4687e
Ivchenko, N.
c892df9e-e2a0-450f-bf77-2673e029f565
Lanchester, B.S.
e864533e-eea0-471f-a3f9-7c70c25be55b
Ashrafi, M.
fb831af1-1df3-4d60-9071-2ae3637b4944
Whiter, D.
9a30d7b6-ea41-44fb-bd52-3ff1964eca5c
Marklund, G.
ca3a83f3-e335-4d69-b5e3-2dad226e339f
Sullivan, J.
38fa668a-22be-4479-bcac-5d2b54fa526e
Dahlgren, H., Ivchenko, N., Lanchester, B.S., Ashrafi, M., Whiter, D., Marklund, G. and Sullivan, J.
(2009)
First direct optical observations of plasma flows using afterglow of O+O+ in discrete aurora.
Journal of Atmospheric and Solar-Terrestrial Physics, 71 (2), .
(doi:10.1016/j.jastp.2008.11.015).
Abstract
Imaging of active structured aurora in the forbidden O+ ion line at 732.0 nm provides a possibility of direct observation of plasma drifts in the topside ionosphere. The metastable O+ 2P state has a radiative lifetime of 5 s, so the oxygen ions can be detected after the precipitation creating them has ceased. The decay time of the O+ emission is studied and modelled with a time-dependent electron transport and ion chemistry model. Four examples are given of O+ afterglow observed with the multi-spectral imager, auroral structure and kinetics (ASK), which was located near Tromsø, Norway, in 2006. Estimates are given of drift velocities resulting from the analysis of the afterglow motions. Bulk plasma velocities of 340 and 720 m/s directed eastwards were found for two afterglowing arc filaments, corresponding to southward electric fields of 18 and 40 mV/m, respectively.
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Published date: February 2009
Keywords:
ionosphere, plasma drift, aurora, oxygen ion, electric fields
Organisations:
Physics & Astronomy
Identifiers
Local EPrints ID: 146821
URI: http://eprints.soton.ac.uk/id/eprint/146821
ISSN: 1364-6826
PURE UUID: 6a4aa8e1-7464-4ac3-b506-3998573d9cbf
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Date deposited: 22 Apr 2010 14:08
Last modified: 14 Mar 2024 02:54
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Contributors
Author:
H. Dahlgren
Author:
N. Ivchenko
Author:
B.S. Lanchester
Author:
M. Ashrafi
Author:
G. Marklund
Author:
J. Sullivan
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