Cassini VIMS observations of latitudinal and hemispheric variations in Saturn's infrared auroral intensity

Sarah V. Badman, Chihiro Tao, Adrian Grocott, Satoshi Kasahara, Henrik Melin, Robert H. Brown, Kevin H. Baines, Masaki Fujimoto, Tom Stallard

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

The intensity of Saturn's infrared H3+ aurora is investigated using Cassini VIMS images acquired during October 2006-February 2009. Polar and main oval auroral regions were defined in both hemispheres, which extend between 0-10° and 10-25° co-latitude, respectively. Average intensities were computed for these regions and compared. While the northern and southern main oval regions covered a similar range of intensities, the southern main oval was on average more intense by a factor of ∼1.3. The emission from the southern polar region was usually less intense than the main oval emissions, while this was only the case for approximately half of the northern hemisphere images. The northern hemisphere polar region displayed intensities more than twice as high as those in the south and the difference between the two hemispheres was most pronounced on the dayside. In general, more intense polar emissions were accompanied by more intense main oval emissions. Possible explanations for the hemispheric and latitudinal differences are discussed in terms of particle energies and fluxes, ionospheric conductivity, temperature and magnetic field strength.

Original languageEnglish (US)
Pages (from-to)367-375
Number of pages9
JournalIcarus
Volume216
Issue number2
DOIs
StatePublished - Dec 1 2011

Keywords

  • Aurorae
  • Infrared observations
  • Saturn

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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    Badman, S. V., Tao, C., Grocott, A., Kasahara, S., Melin, H., Brown, R. H., Baines, K. H., Fujimoto, M., & Stallard, T. (2011). Cassini VIMS observations of latitudinal and hemispheric variations in Saturn's infrared auroral intensity. Icarus, 216(2), 367-375. https://doi.org/10.1016/j.icarus.2011.09.031