Corotation lag of the Jovian atmosphere, ionosphere, and magnetosphere

Journal Article · Sat Apr 01 04:00:00 EST 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA04p03761· OSTI ID:6051189

Huang, T S; Hill, T W ^[1]

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1. Rice Univ., Houston, TX (USA)

The authors modify the Jovian ionosphere-magnetosphere coupling model presented by Hill (1979) to include rotational slippage of the neutral atmosphere at ionospheric heights, relative to a frame of reference corotating rigidly with Jupiter. In the modified model, as altitude increases, the drift velocities of neutrals and ions relative to the corotating frame increase from zero at the bottom of the ionosphere to their respective maximum values at the top, and the corotation lag of the magnetosphere is enhanced for a given rate of mass loading of the magnetosphere. The height variations of the drift velocities of neutrals and ions in the ionosphere and the enhancement factor for the corotation lag of the magnetosphere are related to the atmospheric eddy diffusion coefficient at ionospheric heights. On the basis of ionospheric properties deduced from measurements of Pioneer 11, Voyager 1, and Voyager 2, they derive height profiles of ion and neutral drift speed for various possible values of the eddy diffusion coefficient. If they accept the ion injection rate from Io (10{sup 29} ions/s) and the ion transport rate through the Jovian magnetosphere (3 {times} 10{sup 28} ions/s), corresponding to the observed values of the corotation lag of the Io torus ({delta}{omega}{sub I} = 0.04{omega}{sub j}) and the critical distance for magnetospheric corotation (L{sub 0} = 20), respectively, the effective ionospheric conductance is reduced by a factor of the order of 10, resulting in an enhanced corotation lag, for a given rate of mass loading, by the same factor compared to earlier models. The eddy diffusion coefficient in the high-latitude ionosphere is inferred to be {approximately} 10{sup 13} n{sub n}{sup {minus}1/2}m{sup 1/2}/s, or about a factor of 20 larger than the value inferred from Voyager measurements at near-equatorial latitudes.

• OSTI ID: 6051189
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALTITUDE
ATMOSPHERES
CHARGED-PARTICLE TRANSPORT
DIFFUSION
ION DRIFT
JUPITER PLANET
MASS TRANSFER
MATHEMATICAL MODELS
MODIFICATIONS
MOTION
PLANETARY ATMOSPHERES
PLANETARY IONOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
RADIATION TRANSPORT
ROTATION
SPACE VEHICLES
VARIATIONS
VEHICLES
VOYAGER SPACE PROBES