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Editor's Highlight
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GEOPHYSICAL RESEARCH LETTERS,
VOL. 34,
L11105,
doi:10.1029/2007GL029881,
2007
Observed emission rates in sprite streamer heads
H. C. Stenbaek-Nielsen
Geophysical Institute, University of Alaska, Fairbanks, Alaska, USA
M. G. McHarg
Department of Physics, United States Air Force Academy, Colorado Springs, Colorado, USA
T. Kanmae
Geophysical Institute, University of Alaska, Fairbanks, Alaska, USA
D. D. Sentman
Geophysical Institute, University of Alaska, Fairbanks, Alaska, USA
Abstract
Sprite observations at 10,000 fps have shown tendrils and branches to be formed by bright streamer heads moving at ∼107 m/s. The streamer heads typically brighten as they move up or down, often saturating the detector. We present here inferred
emission rates. The streamer heads are presumably smaller than our 140 m spatial resolution and, therefore, they have to be
treated as point sources. The optical emissions are assumed to be dominated by the N2 1P band and comparing with stars in the images we find total emission rates in individual streamer heads ranging from 4 1021 to 3 1024 photons/s. For a 25 m streamer head the range of average brightness would be 9 108–5 1011 R. Alternatively, using a volume emission rate of 8 1011 photons/cm3/s the size range would be 10 to 100 m.
Received 2
March
2007;
accepted 1
May
2007;
published 6
June
2007.
Keywords: sprites.
Index Terms: 3304 Atmospheric Processes: Atmospheric electricity; 3324 Atmospheric Processes: Lightning; 3332 Atmospheric Processes: Mesospheric dynamics; 3334 Atmospheric Processes: Middle atmosphere dynamics (0341, 0342); 3359 Atmospheric Processes: Radiative processes.
Read Full Article (file size: 173460 bytes) Cited by
Citation: Stenbaek-Nielsen, H. C., M. G. McHarg, T. Kanmae, and D. D. Sentman
(2007),
Observed emission rates in sprite streamer heads,
Geophys. Res. Lett.,
34,
L11105,
doi:10.1029/2007GL029881.
Copyright 2007 by the American Geophysical Union.
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