Journal article
Are Saturn electrostatic discharges really superbolts? A temporal dilemma
Geophysical research letters, Vol.34(6), pp.06202-n/a
03/2007
DOI: 10.1029/2006GL028841
Abstract
Saturn electrostatic discharges (SED) are freely-propagating radio emissions detected in the high frequency (HF) radio band (1-40 MHz) associated with electrical discharge (i.e., lightning) from storms in Saturn's atmosphere. While SEDs responsible for the RF emission are considered to be very energetic superbolts (>1013 J), this determination is intimately related to the temporal nature of the discharge itself. As we demonstrate, if we assume the discharge has similar temporal properties as terrestrial cloud-to-ground discharges (with a stroke time scale ~70 mus), then indeed the discharge energy has to be ~ 1013 J in order account for the Cassini-observed radiated HF power of ~50 W/Hz. However, if the discharge duration is faster than the terrestrial case (i.e., ~1 mus), the energy of the discharge can be weaker than the terrestrial case since the central peak of the emission shifts closer to the HF band. Because of the near-flat SED spectra measured in the HF which favors a faster discharge, we conclude that the high level of radiated HF power from SEDs may have less to do with any extreme super-bolt strength of the discharge and has more to do with the intrinsic quick time-scale of relatively weaker discharges.
Details
- Title: Subtitle
- Are Saturn electrostatic discharges really superbolts? A temporal dilemma
- Creators
- William M. Farrell - Goddard Space Flight CenterMichael L. Kaiser - Goddard Space Flight CenterGeorg Fischer - University of IowaPhilippe Zarka - Laboratoire d’études spatiales et d’instrumentation en astrophysiqueWilliam S. Kurth - University of IowaDonald A. Gurnett - University of Iowa
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.34(6), pp.06202-n/a
- Publisher
- American Geophysical Union
- DOI
- 10.1029/2006GL028841
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Language
- English
- Date published
- 03/2007
- Academic Unit
- Physics and Astronomy
- Record Identifier
- 9984455366902771
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