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| Titel |
Laboratory Experiments Simulating Sprites on Earth, Venus and Jupiter. |
| VerfasserIn |
Sander Nijdam, Daria Dubrovin, Eddie van Veldhuizen, Ute Ebert, Yoav Yair, Colin Price |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250041791
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| Zusammenfassung |
| Large sprite discharges at high atmospheric altitudes have been found to be physically similar
to small streamer discharges in air at sea level density. Based on this understanding, we
investigate sprite discharges on Earth and possible sprite discharges on Venus or Jupiter-like
planets through laboratory experiments on streamers in artificial air and appropriate CO2-N2
and H2-He mixtures.
From ICCD images, we have determined general streamer morphology, minimal streamer
diameters and propagation velocities. We have found that for all three gas mixtures, the
reduced minimal diameter (nÃdmin, density times diameter) is constant as a function of
pressure, although the exact number varies with a factor of 5, depending on the gas
composition. This confirms the similarity laws for streamers.
Morphology and velocities of sprites on Venus and Jupiter are also quite similar to those on
earth, but light emissions in the visible range are much fainter, by two orders of
magnitude.
Spectra emitted by streamer and glow discharges in the three different gas mixtures are
measured as well; they are dominated by the minority species N2 on Venus and Earth, while
signatures of both main species (H2-He) are found on Jupiter-like planets. We also show that
the spectra of short repetitive glow discharges and streamer discharges are very similar. |
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