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| Titel |
Characteristics of lightning flashes generating dancing sprites above
thunderstorms |
| VerfasserIn |
Serge Soula, Janusz Mlynarczyk, Martin Füllekrug, Nicolau Pineda, Jean-François Georgis, Oscar van der Velde, Joan Montanyà, Ferran Fabro |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250145399
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| Publikation (Nr.) |
 EGU/EGU2017-9337.pdf |
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| Zusammenfassung |
| During the night of October 29-30, 2013, a low-light video camera at Pic du Midi (2877 m) in
the French Pyrénées, recorded TLEs above a very active storm over the Mediterranean Sea.
The minimum cloud top temperature reached -73˚ C at ∼1600 UTC while its cloud to
ground (CG) flash rate reached ∼30 fl min−1. Some sprite events with long duration are
classified as dancing sprites. We analyze in detail the temporal evolution and estimated
location of sprite elements for two cases of these events. They consist in series of sprite
sequences with a duration that exceeds 1 second. By associating the cloud structure, the
lightning activity, the electric field radiated in a broad range of low frequencies and the
current moment waveform of the lightning strokes, some findings are highlighted: (i) In
each series, successive sprite sequences reflect the occurrence time and location of
individual positive lightning strokes across the stratiform region. (ii) The longer
time-delayed (> 20 ms) sprite elements correspond to the lower impulsive charge
moment changes (iCMC) of the parent stroke (< 200 C km) and they are shifted
few tens of kilometres from their SP+CG stroke. However, both short and long
time-delayed sprite elements also occur after strokes that produce a large iCMC and that
are followed by a continuing current. (iii) The long time-delayed sprite elements
produced during the continuing current correspond to surges in the current moment
waveform. They occur sometimes at an altitude apparently lower than the previous
short time-delayed sprite elements, possibly because of the lowered altitude of
the ionosphere potential. (iv) The largest and brightest sprite elements produce
significant current signatures, visible when their delay is not too short (∼3-5 ms). |
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