Sondrestrom radar observations of the effect of the IMF by component on polar convection

Technical Report · Tue Jan 01 04:00:00 EST 1985

OSTI ID:7020957

Beaujardiere, de la; Wickwar, V B; King, J H

Average patterns of convection, derived from Sondrestrom radar observations, reveal that the interplanetary magnetic field dawn-dusk component (IMF By) strongly influences the nighttime polar convection. The convection for one orientation of By is not the mirror image of the other orientation. A positive By seems to organize the velocities such that, at all local times, they are predominantly westward within the radar latitude range. On a case-by-case basis, auroral oval boundaries can be determined by coincident DMSP particle data and by radar-measured E-region densities. On one occasion of positive By, sunward flow (i.e., westward flow) is observed in the polar cap between dusk and midnight. For large negative By, large southward velocities are observed about three hours before midnight. These are the only times when the predominant velocity component is clearly southward. When By is negative, in the midnight and dawn sectors, the plasma velocities appear random. However, the average drifts are mostly southward. The radar average patterns are compared with theoretical predictions.

• Research Organization: SRI International, Menlo Park, CA (USA)
• OSTI ID: 7020957
• Report Number(s): AD-A-172249/5/XAB
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
CONVECTION
DENSITY
E REGION
EARTH ATMOSPHERE
ELECTRIC FIELDS
ENERGY TRANSFER
HEAT TRANSFER
IMAGES
INCOHERENT SCATTERING
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC FIELDS
MASS TRANSFER
MEASURING INSTRUMENTS
PHYSICAL PROPERTIES
PLANETARY IONOSPHERES
POLAR REGIONS
RADAR
RANGE FINDERS
SCATTERING
VELOCITY