Measurements and modelling of intermediate, descending, and sporadic layers in the lower ionosphere: Results and implications for global-scale ionospheric-thermospheric studies
The authors demonstrate that conventional ionosondes can provide long-term observations on intermediate, descending, and transitional layers in the 100-200 km altitude region of the ionosphere. Using 15 consecutive days of observations at Townsville, Australia, during the SUNDIAL campaign of September 1989, they tracked the birth of the layers at altitudes above 150 km and their systematic downward motion to the 110 km region at rates between 4 and 5 km/hr. The observations are compared with NCAR TIGCM simulations, and the results show: (1) that the layering process is identifiable with meridional wind-shear-node convergence of ions; (2) that zonal wind controls of the layers are insignificant under the prevailing conditions; and (3) that electric fields play an important role in the effectiveness of the ion-convergence and downward transport processes at altitudes above 125 km. The measurement and modeling comparisons are the first of a kind, providing insight into the relative roles of winds and electric fields, and opening possibilities for determining the global characteristics of the layers and their cause-effect roles in the dynamics of the lower ionospheric-thermospheric domain.
- OSTI ID:
- 5362330
- Journal Information:
- Geophysical Research Letters (American Geophysical Union); (United States), Vol. 19:2; ISSN 0094-8276
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
IONOSPHERE
ELECTRODYNAMICS
MORPHOLOGY
THERMOSPHERE
WIND
CHARGED-PARTICLE TRANSPORT
COMPARATIVE EVALUATIONS
DYNAMICS
ELECTRIC FIELDS
F2 LAYER
GLOBAL ASPECTS
IONOSONDES
LAYERS
MATHEMATICAL MODELS
PLASMA DENSITY
SPORADIC E
VIRTUAL HEIGHT
DIMENSIONS
E REGION
EARTH ATMOSPHERE
ELECTRONIC EQUIPMENT
EQUIPMENT
EVALUATION
F REGION
HEIGHT
MECHANICS
PLANETARY IONOSPHERES
RADIATION TRANSPORT
RADIO EQUIPMENT
661320* - Auroral
Ionospheric
& Magnetospheric Phenomena- (1992-)