Doppler shifted H Ly. alpha. emission from Jupiter's aurora

Journal Article · Thu Jun 01 04:00:00 EDT 1989 · Geophysical Research Letters (American Geophysical Union); (USA)

DOI:https://doi.org/10.1029/GL016i006p00587· OSTI ID:6050712

Clarke, J T ^[1]; Trauger, J ^[2]; Waite, Jr, J H ^[3]

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1. Univ. of Michigan, Ann Arbor (USA)
2. Jet Propulsion Lab., Pasadena, CA (USA) California Institute of Technology, Pasadena (USA)
3. Southwest Research Institute, San Antonio, TX (USA)

IUE observations of the aurora on Jupiter have been performed with high spectral resolution in a search for Doppler shifted H Ly {alpha} emission produced through charge exchange by fast precipitating protons, as observed in the Earth's aurora. No emission has been observed corresponding to proton energies greater than 200 eV, placing a strict upper limit on the contribution of KeV - MeV protons to the production of Jupiter's aurora. However, a large fraction of the H Ly {alpha} emission has appeared Doppler-shifted mainly toward the blue by roughly 50 km/sec, corresponding to a kinetic energy of 10-20 eV for a fast proton or H atom, and there are higher velocity wings on the line extending out to equivalent energies of 150-200 eV. The blue shift indicates motion up out of the atmosphere, and the authors suggest that the emission results from the in situ acceleration of ionospheric protons in Jupiter's auroral ionosphere by analogy to the ionospheric potentials observed in the Earth's auroral zones. These observations demonstrate that the acceleration of ionospheric plasma in an H{sub 2} atmosphere can lead to bright Ly {alpha} emission, with implications for the production of the outer planet airglow emissions.

• OSTI ID: 6050712
• Journal Information: Geophysical Research Letters (American Geophysical Union); (USA), Journal Name: Geophysical Research Letters (American Geophysical Union); (USA) Vol. 16:6; ISSN 0094-8276; ISSN GPRLA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACCELERATION
AIRGLOW
AURORAE
CHARGE EXCHANGE
CHARGED-PARTICLE PRECIPITATION
DATA ANALYSIS
DOPPLER EFFECT
EARTH PLANET
ELEMENTS
HYDROGEN
JUPITER PLANET
LIMITING VALUES
LYMAN LINES
NONMETALS
PLANETARY IONOSPHERES
PLANETS
PLASMA
PLASMA DRIFT
PROTON PRECIPITATION