Ionospheric flows associated with a transpolar arc

Journal Article · Sat Dec 01 04:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA12p21169· OSTI ID:5377978

Nielsen, E ^[1]; Carven, J D; Frank, L A ^[2]; Heelis, R A ^[3]

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1. Max-Planck-Institut fuer Aeronomie, Katlenburg-Lindau (West Germany)
2. Univ. of Iowa, Iowa City (USA)
3. Univ. of Texas, Richardson (USA)

A theta aurora is observed in the northern hemisphere on January 21, 1982, using the auroral imaging instrumentation on board the DE 1 spacecraft. The period of observations is from 1,807 to 2,121 UT. The transpolar arc is observed to advance toward the dusk sector, in the direction of the interplanetary magnetic field B{sub y} component. Coincidentally, the intersection between the arc and the auroral oval near local midnight passes through the field of view of the STARE coherent radar system, thereby providing the opportunity for measurements of the spatial pattern of ionospheric electron drift velocities. The convection flow in the arc is directed toward the nightside auroral oval, where it divides into westward and eastward directed flows (eastward and westward electrojets). Sunward flows are not observed along the transpolar arc near midnight. The overall flow pattern is identical to that expected at the Harang discontinuity. Two traversals of the auroral oval and polar cap with DE 2 demonstrate that, as expected, transitions from antisunward to sunward flow are associated with the dayside of the transpolar arc. The evolution of the arc and its convective features observed simultaneously on both the dayside and the nightside allow a more complete description of its global configuration than has been made previously.

• OSTI ID: 5377978
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:A12; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640201* -- Atmospheric Physics-- Auroral
Ionospheric
& Magetospheric Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
AURORAL OVAL
CONVECTION
CURRENTS
DISTRIBUTION
EARTH ATMOSPHERE
EARTH PLANET
ELECTRIC CURRENTS
ELECTROJETS
ELECTRON DRIFT
ENERGY TRANSFER
HEAT TRANSFER
INTERPLANETARY MAGNETIC FIELDS
IONOSPHERE
MAGNETIC FIELDS
MASS TRANSFER
MEASURING INSTRUMENTS
NORTHERN HEMISPHERE
PLANETARY IONOSPHERES
PLANETS
POLAR-CAP AURORAE
RADAR
RANGE FINDERS
SATELLITES
SPATIAL DISTRIBUTION