The control of auroral zone dynamics and thermodynamics by the interplanetary magnetic field dawn-dusk (Y) component

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA09p11921· OSTI ID:6048190

Sica, R J ^[1]; Hernandez, G ^[2]; Emery, B A; Roble, R G ^[3]; Smith, R W; Rees, M H ^[4]

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1. Univ. of Western Ontario, London (Canada)
2. Univ. of Washington, Seattle (USA)
3. National Center for Atmospheric Research, Boulder, CO (USA)
4. Univ. of Alaska, Fairbanks (USA)

Previous theoretical and experimental studies have shown that the dawn-dusk component of the interplanetary magnetic field (IMF B{sub y}) expands the classical symmetric two-cell convection pattern toward dusk (B{sub y} negative) or toward dawn (B{sub y} positive) in the northern hemisphere, altering the ion drag forcing on the neutral atmosphere. Measurements of the neutral dynamics associated with these convection patterns have been presented primarily at magnetic latitudes greater than 70{degree} in the polar cap. In this study, nights with coincident IMF measurements have been selected from the extensive four-year auroral zone thermospheric wind and temperature data set derived from Fabry-Perot spectrometer measurements of the Doppler shifts and widths of the O({sup 1}D) 15,867 cm{sup {minus}1} (630.0 nm) emission from College, Alaska. Averages from 112 nights of measurements from College were also computed using a selection criterion that depended on the previous 2 hours of IMF measurements (case 2). This procedure yielded averages that differed at times from case 1. The wind and temperature averages for both cases show large variations with B{sub y} in the auroral zone. The wind averages for B{sub y} negative and positive are compared with National Center for Atmospheric Research thermospheric general circulation model predictions that use a B{sub y}-dependent model of ionospheric convection. The results for B{sub y} negative and positive are compared with National Center for Atmospheric Research thermospheric general circulation model predictions that use a B{sub y}-dependent model of ionospheric convection. The results for B{sub y} negative compare favorably with the averages, but there are significant differences between model calculations and averages for the B{sub y} positive case.

• OSTI ID: 6048190
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A9; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAL OVAL
AURORAL ZONES
COMPARATIVE EVALUATIONS
CONVECTION
DYNAMICS
EARTH ATMOSPHERE
EARTH PLANET
ENERGY TRANSFER
HARANG DISCONTINUITY
HEAT TRANSFER
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC FIELDS
MASS TRANSFER
MECHANICS
NORTHERN HEMISPHERE
PLANETARY IONOSPHERES
PLANETS
THERMODYNAMICS
THERMOSPHERE
VARIATIONS
WIND