Peak emission altitude of Saturn's H3+ aurora

Tom S. Stallard, Henrik Melin, Steve Miller, Sarah V. Badman, Robert H. Brown, Kevin H. Baines

Research output: Contribution to journalArticlepeer-review

23 Scopus citations


Here we present the first detailed measurement of the altitudinal profile of H3+ emission within Saturn's ionosphere, made using images taken by the VIMS instrument on Cassini on 11-12 October 2006, during a chance alignment between the visible limb of the planet and the position of the main auroral emission. Using this, we show that the emission profile of H 3+ can be fitted to a reasonable accuracy with a Gaussian, producing a calculated peak emission altitude at 1155 (±25) km that differs significantly from previous observations of the UV emission profile, and also from the predictions of models that calculated the H3 + emission profile, which suggested that there would be extended emission above the peak emission altitude. This lack of extended emission is most simply explained by differences in the scale height of H and H2, suggesting that models overestimate H2 at high altitudes, with little H2 from 2000km above the 1bar level.

Original languageEnglish (US)
Article numberL15103
JournalGeophysical Research Letters
Issue number15
StatePublished - Aug 16 2012

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)


Dive into the research topics of 'Peak emission altitude of Saturn's H3+ aurora'. Together they form a unique fingerprint.

Cite this