Rocketborne observations of ion convection and electric fields in dayside and nightside visual auroral arcs

Journal Article · Sat Aug 01 00:00:00 EDT 1981 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA086iA08p06899· OSTI ID:5801837

Yau, A W; Whalen, B A; Creutzberg, F

We present ionospheric ion convection measurements in a series of four rocket payloads in and near dayside and nightside auroral arcs: one at Cape Parry (75.4/sup 0/N invariant latitude) near 1300 MLT and three at Churchill (70.0/sup 0/N invariant latitude) between 1900 and 2200 MLT. Direct measurements were made of the ionospheric ion velocity distribution function, and the observed ion convection velocities and equivalent convective electric fields were correlated with the energetic particle precipitation, the optical morphology of the aurora, and the topology of the geomagnetic field. Both in the postnoon and premidnight sectors it was observed that (1) equatorward of the region(s) of precipitation the ion flow was predominantly westward, with velocity of about 1 km/s; (2) poleward of the region(s) the flow was predominantly westward, with velocity of about 1 km/s; (2) poleward of the region(s) the flow was predominantly eastward: (3) the change in the flow direction, where observed, occurred near though not exactly at the edges of the precipitation region; (4) the flow inside the precipitation region was lower; (5) the reversal of the ion flow, where observed, occurred on closed magnetic field lines; and (6) the convective electric field typically dropped from 40 to 80 mV/m outside the precipitation region to 10 to 30 mV/m within. In the dayside Cape Perry flight, where quantitative photometric measurements were available, detailed anticorrelation between the ion convection speed and the green line emission intensity was also observed.

• Research Organization: Herzberg Institute of Astrophysics, National Research Council of Canada, Ottawa, Canada K1A OR6
• OSTI ID: 5801837
• Journal Information: J. Geophys. Res.; (United States), Vol. 86:A8
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
ELECTRIC FIELDS
ION DRIFT
CHARGED-PARTICLE PRECIPITATION
DAILY VARIATIONS
GEOMAGNETIC FIELD
IONOSPHERE
MAGNETIC FIELD CONFIGURATIONS
PLASMA EXPANSION
EARTH ATMOSPHERE
EXPANSION
MAGNETIC FIELDS
PLANETARY IONOSPHERES
VARIATIONS
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena