Neutral and ion composition changes in the F region over Millstone Hill during the equinox transition study

Journal Article · Sun Apr 01 00:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA04p04129· OSTI ID:5152291

Oliver, W L ^[1]

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1. Boston Univ., MA (United States)

The author uses overhead ionospheric incoherent scatter radar data from Millstone Hill to deduce the stormtime variations of the thermospheric temperature, O and N{sub 2} densities, and F{sub 1} region ion composition during the Equinox Transition Study of September 17-24, 1984. Using the measured neutral temperature profile and O density at 400 km altitude, they extrapolate to determine O density changes in the lower thermosphere. Using these O densities and the measured electron densities, he deduces the variation of the N{sub 2} density. His initial attempt leads to the deduction of large depletions in both O and N{sub 2} in the lower thermosphere. On using the MSIS model neutral temperatures for the extrapolation, however, he computes O depletions having magnitudes more comparable with theoretical predictions and N{sub 2} variations consistent with expected thermal expansion effects. He speculates that the radar-measured neutral temperature were contaminated by ion-neutral frictional heating effects during the disturbed periods of the ETS and that this served to invalidate neutral density extrapolations made with these temperatures. Further, they computes the height of 50% O{sup +} ion composition in the F{sub 1} region and the height of the peak electron density in the ionosphere, and, upon comparing these, find that the height of the peak on the disturbed days was located in the lower F{sub 1} consequences for methods of deducing neutral winds from the height of the F layer, for these methods rely on the peak containing primarily O{sup +} ions.

• OSTI ID: 5152291
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A4; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
F REGION
IONIC COMPOSITION
THERMOSPHERE
CHEMICAL COMPOSITION
TEMPERATURE MEASUREMENT
COMPARATIVE EVALUATIONS
DATA ANALYSIS
ELECTRON DENSITY
HEIGHT
MAGNETIC STORMS
NITROGEN
OXYGEN
OXYGEN IONS
RADAR
VARIATIONS
WIND
CHARGED PARTICLES
DIMENSIONS
EARTH ATMOSPHERE
ELEMENTS
EVALUATION
IONOSPHERE
IONS
MEASURING INSTRUMENTS
NONMETALS
PLANETARY IONOSPHERES
RANGE FINDERS
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena