1611.full.pdf (688.67 kB)
On the anticorrelation between H-3(+) temperature and density in giant planet ionospheres
journal contribution
posted on 2015-10-13, 11:31 authored by H. Melin, Thomas S. Stallard, J. O'Donoghue, S. V. Badman, S. Miller, J. S. D. BlakeThe intensity of H+3 emission can be driven by both temperature and density, and when fitting a set of infrared H+3 line spectra, an anticorrelation between the fitted temperatures and densities is commonly observed. The ambiguity present in the existing published literature on how to treat this effect puts into question the physical significance of the derived parameters. Here, we examine the nature of this anticorrelation and quantify the inherent uncertainty in the fitted temperature and density that this produces. We find that the uncertainty produced by the H+3 temperature and density anticorrelation is to a very good approximation equal to the uncertainties that are derived from the fitting procedure invoking Cramer's rule. This means that any previously observed correlated variability in the observed H+3 temperature and density outside these errors, in the absence of other error sources, are statistically separated and can be considered physical. These results are compared to recent ground-based infrared Keck Near InfRared echelle SPECtrograph (NIRSPEC) observations of H+3 emission from Saturn's aurora, which show no clear evidence for large-scale radiative cooling, but do show stark hemispheric differences in temperature.
History
Citation
Monthly Notices of the Royal Astronomical Society, 2014, 438 (2), pp. 1611-1617 (7)Author affiliation
/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and AstronomyVersion
- VoR (Version of Record)
Published in
Monthly Notices of the Royal Astronomical SocietyPublisher
Oxford University Press (OUP)issn
0035-8711Acceptance date
2013-11-27Copyright date
2013Available date
2015-10-13Publisher DOI
Publisher version
http://mnras.oxfordjournals.org/content/438/2/1611Language
enAdministrator link
Usage metrics
Categories
Keywords
Science & TechnologyPhysical SciencesAstronomy & Astrophysicsplanets and satellites: atmospheresplanets and satellites: auroraeplanets and satellites: gaseous planetsplanets and satellites: magnetic fieldsRADIO SCIENCE OBSERVATIONSJOVIAN UPPER-ATMOSPHEREKECK-II TELESCOPEINFRARED-SPECTRUMAURORAL EMISSIONJUPITERNEPTUNEVARIABILITYNIRSPECSATURN
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC