Upper-thermospheric observations and neutral-gas dynamics at high latitudes during solar maximum

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6862038

Tschan, C R

The primary objective was to understand the time-dependent dynamics of high-latitude thermospheric neutral winds. A unique 70-orbit December-solstice dataset of Dynamics Explorer 2 (DE-2) satellite data was established, with coverage of both polar caps during the same orbit. Analysis of this data led to the characterization of four basic high-latitude neutral-wind signature categories for each hemisphere under various interplanetary-magnetic-field (IMF) configurations. In addition, neutral-gas forcing simulations for the same solar-maximum December-solstice conditions using the NCAR thermospheric general circulation model (TGCM) showed that the orientation of the pressure-gradient force in the winder northern hemisphere was different from the summer southern hemisphere, explaining the differences in neutral-wind flow patterns systematically observed by DE-2 in opposite hemispheres. The variations in the pressure-gradient forces in opposite hemispheres were ascribed to density variations and temperature gradients, resulting from a superposition of solar-EUV, Joule, and cusp heating. The DE-2 dataset was then used to conduct two different time-dependent tests of the NCAR-TGCM. Finally, a technique for short-range forecasting of the high-latitude ion-convection parameters was noted.

• Research Organization: Michigan Univ., Ann Arbor (USA)
• OSTI ID: 6862038
• Country of Publication: United States
• Language: English

Related Subjects

640104 -- Astrophysics & Cosmology-- Solar Phenomena
640200* -- Atmospheric Physics
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERIC CIRCULATION
EARTH ATMOSPHERE
EXPLORER SATELLITES
FLUID FLOW
FORECASTING
GAS FLOW
ION MOBILITY
MOBILITY
PARTICLE MOBILITY
POLAR REGIONS
PRESSURE GRADIENTS
SATELLITES
SOLAR ACTIVITY
THERMOSPHERE