HR: 16:00h
AN: SA24A-03 INVITED     [Abstracts]
TI: Jupiter Thermospheric General Circulation Model (JTGCM): Global Structure and Dynamics Driven by Auroral and Joule Heating
AU: * Bougher, S W
EM: bougher@umich.edu
AF: Space Physics Research Laboratory, 2455 Hayward Avenue, University of Michigan, Ann Arbor, MI 48109 United States
AU: Waite, J H
EM: hunterw@umich.edu
AF: Space Physics Research Laboratory, 2455 Hayward Avenue, University of Michigan, Ann Arbor, MI 48109 United States
AU: Majeed, T
EM: tariqm@umich.edu
AF: Space Physics Research Laboratory, 2455 Hayward Avenue, University of Michigan, Ann Arbor, MI 48109 United States
AU: Gladstone, G R
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78228 United States
AB: A growing multi-spectral database plus recent Galileo descent measurements are being used to construct a self-consistent picture of the Jupiter thermosphere/ionosphere system. The proper characterization of Jupiter's upper atmosphere, imbedded ionosphere, and auroral features requires the examination of underlying processes including the feedbacks of energetics, neutral-ion dynamics, composition, and magnetospheric coupling. A fully 3-D Jupiter Thermospheric General Circulation Model (JTGCM) has been developed and is being exercised to address global temperatures, 3-component neutral winds, and neutral-ion specie distributions. The domain of this JTGCM extends from 20-microbar (capturing hydrocarbon cooling) to 0.1-picobar (including auroral/Joule heating processes). The resulting JTGCM has been fully spun-up and integrated for 40-60 Jupiter rotations. Results from two JTGCM cases incorporating moderate auroral heating, ion drag, and moderate to strong Joule heating processes are presented. The neutral horizontal winds at ionospheric heights vary from 0.5 km/s to 1.2 km/s, atomic hydrogen is transported equatorward, and auroral exospheric temperatures range from ~1200-1300 K to above 3000 K depending on the magnitude of Joule heating. The equatorial temperature profiles from the JTGCM are compared with the measured temperature structure from the Galileo ASI dataset. The best fit to the Galileo data implies that the major energy source for maintaining the equatorial temperatures is due to dynamical heating induced by the low latitude convergence of the high-latitude driven thermospheric circulation. The magnitude of this equatorial heating, and the strength of the underlying global thermospheric circulation, are strongly dependent upon magnetospheric coupling which regulates Joule heating. Simulated fields and diagnostics from the JTGCM are compared to available multi-spectral and spacecraft observations.
DE: 0358 Thermosphere--energy deposition
DE: 5707 Atmospheres--structure and dynamics
DE: 5719 Interactions with particles and fields
SC: SPA-Aeronomy [SA]
MN: 2005 Joint Assembly