A joint study of the lower ionosphere by radar, lidar, and spectrometer

Miscellaneous · Tue Jan 01 00:00:00 EST 1991

OSTI ID:6788252

Zhou, Qihou

The dynamics and associated phenomena occurring in the lower ionospheric-E region, especially the mesopause region between 80 km to 110 km at low latitude, are studied. In particular, incoherent scatter radar (ISR), sodium lidar and airglow spectrometry are used to study the ionospheric structure and neutral sodium structure. The simultaneous study of the ionospheric plasma and neutral atomic sodium is unprecedented in scope and detail. The joint study of the mesopause region reveals that plasma, neutral densities and temperature are interconnected through the same atmospheric dynamics. The theme of the thesis is to explain the formation of the controversial sporadic sodium layer (SSL) events. Strong correlation is established between the average total ion and sodium concentrations, and between sporadic-E and SSL events. The mechanism proposed in the thesis, which invokes temperature fluctuations induced by tides and gravity waves, finds good agreement with observations. Tides and gravity waves can converge ions into thin layers through the windshear mechanisms and can influence the concentration of atomic sodium through temperature fluctuations. Sodium abundance is shown to augment rapidly when the temperature is increased. Gravity wave theory states that the ion convergence node coincides with a temperature maximum for a westward propagating gravity wave, and coincides with a temperature minimum for an eastward propagating wave. Because tidal winds propagate westward, the ion layer coincides with the temperature maximum which consequently induces higher sodium concentration. This can account for the general correlation between sodium and total ion concentration and is supported by the O2(0-1) rotational temperature. Gravity waves and their interaction with tidal winds are believed to be responsible for the close association between sudden sodium layers and sporadic-E layers.

• Research Organization: Pennsylvania State Univ., University Park, PA (United States). Davey Lab.
• OSTI ID: 6788252
• Resource Relation: Other Information: Ph.D. Thesis
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
E REGION
DYNAMICS
SODIUM
ECOLOGICAL CONCENTRATION
AIRGLOW
CORRELATIONS
GRAVITY WAVES
ION TEMPERATURE
IONOSPHERE
MESOSPHERE
OPTICAL RADAR
OXYGEN
SPECTROSCOPY
SPORADIC E
ALKALI METALS
EARTH ATMOSPHERE
ELEMENTS
MEASURING INSTRUMENTS
MECHANICS
METALS
NONMETALS
PLANETARY IONOSPHERES
RADAR
RANGE FINDERS
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)