Astronomy and Astrophysics – Astronomy
Scientific paper
Mar 2011
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2011apj...729..134m&link_type=abstract
The Astrophysical Journal, Volume 729, Issue 2, article id. 134 (2011).
Astronomy and Astrophysics
Astronomy
2
Planets And Satellites: Atmospheres, Planets And Satellites: Aurorae, Planets And Satellites: Individual: Uranus, Planets And Satellites: Magnetic Fields
Scientific paper
Infrared ground-based observations using IRTF, UKIRT, and Keck II of Uranus have been analyzed as to identify the long-term behavior of the H+ 3 ionosphere. Between 1992 and 2008 there are 11 individual observing runs, each recording emission from the H+ 3 Q branch emission around 4 μm through the telluric L' atmospheric window. The column-averaged rotational H+ 3 temperature ranges between 715 K in 1992 and 534 K in 2008, with the linear fit to all the run-averaged temperatures decreasing by 8 K year-1. The temperature follows the fractional illumination curve of the planet, declining from solstice (1985) to equinox (2007). Variations in H+ 3 column density do not appear to be correlated to either solar cycle phase or season. The radiative cooling by H+ 3 is ~10 times larger than the ultraviolet solar energy being injected to the atmosphere. Despite the fact that the solar flux alone is incapable of heating the atmosphere to the observed temperatures, the geometry with respect to the Sun remains an important driver in determining the thermospheric temperature. Therefore, the energy source that heats the thermosphere must be linked to solar mechanisms. We suggest that this may be in the form of conductivity created by solar ionization of atmospheric neutrals and/or seasonally dependent magnetospherically driven current systems.
Encrenaz Th.
Geballe Thomas Ronald
Melin Henrik
Miller Samantha
Stallard Tom
No associations
LandOfFree
Seasonal Variability in the Ionosphere of Uranus does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Seasonal Variability in the Ionosphere of Uranus, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seasonal Variability in the Ionosphere of Uranus will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1184150