Estimation of ionospheric electrodynamic parameters using ionospheric conductance deduced from bremsstrahlung x-ray image data. Technical report

Technical Report · Thu Feb 16 04:00:00 EST 1989

OSTI ID:5594290

Ahn, B; Kroehl, H W; Kamide, Y; Gorney, D J

Various ionospheric electrodynamic parameters are calculated by using ground magnetic records from a total of 88 stations in the northern hemisphere. For this purpose, an instantaneous conductance distribution deduced from the DMSP-F6 bremsstrahlung X-ray image data is utilized. It is a unique opportunity to examine some of the inherent ambiguity in the magnetogram-inversion technique based on a statistically-derived conductance model. Important conclusions are: (1) The pole-ward portion of the westward electrojet in the morning sector is dominated by electric field, while its equatorward portion is dominated by the ionospheric conductance. (2) During a quiet or moderately disturbed period, the major electric potential pattern is roughly circumscribed by the auroral zone conductance belt. (3) The global pattern of the equivalent current system resembles the electrical potential distribution. (4) The electric potential distribution consists generally of a smooth and well-defined two-cell convection pattern without any significantly localized structure. (5) A sunward convection flow is clearly identified over the polar-cap region. (6) During strongly northward IMF periods, significant currents and joule dissipation are observed in the polar cap-region, indicating that the magnetosphere is far from its ground state. (7) The regions of intense joule heating are generally confined to relatively narrow belts. (8) The Region 2 upward current in the morning hemisphere is roughly collocated with the enhanced conductance region. (9) The presently available statistical conductance models can be used, as a first approximation, to study global-scale polar ionospheric electrodynamics.

• Research Organization: Aerospace Corp., El Segundo, CA (USA). Space Sciences Lab.
• OSTI ID: 5594290
• Report Number(s): AD-A-206457/4/XAB; TR-0088(3940-06)-4
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
BREMSSTRAHLUNG
CONVECTION
CURRENTS
DISTRIBUTION
DOCUMENT TYPES
EARTH ATMOSPHERE
EARTH MAGNETOSPHERE
ELECTRIC CONDUCTIVITY
ELECTRIC CURRENTS
ELECTRIC FIELDS
ELECTRICAL PROPERTIES
ELECTRODYNAMICS
ELECTROJETS
ELECTROMAGNETIC RADIATION
ENERGY TRANSFER
GROUND LEVEL
HEAT TRANSFER
HEATING
IMAGES
IONIZING RADIATIONS
IONOSPHERE
LEVELS
MAGNETIC FIELDS
MASS TRANSFER
MATHEMATICAL MODELS
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
PROGRESS REPORT
RADIATIONS
X RADIATION