Spatial relationship between large aspect angle VHF radio aurora and 557. 7-nm emissions: Evidence for refraction

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

OSTI ID:5444365

Hall, G; Moorcroft, D R ^[1]; Cogger, L L ^[2]; Andre, D ^[3]

---

1. Univ. of Western Ontario, London (USA)
2. Univ. of Calgary, Alberta (Canada)
3. Univ. of Saskatchewan, Saskatoon (Canada)

A recently proposed explanation for large aspect angle VHF backscatter observations, based on refraction through auroral ionization structures in the E region (Moorcroft, 1989), has been confirmed by an experimental comparison of observations of auroral E region coherent backscatter at 48.5 MHz (made with the Bistatic Auroral Radar System or BARS) with simultaneous 557.7-nm emissions with a CCD-based all-sky imager. The apparently large aspect angle radio auroral echoes are found to occur predominantly on the side of the visual aurora away from the radar for both the premidnight and the postmidnight sectors. For the Red Lake BARS radar this means that the strongest echoes occur to the north of the visual form, in sharp contrast with previous comparisons, particularly for the premidnight sector, which found that radar echoes occur predominantly southward of the visual aurora. These results are consistent with the proposed explanation based on refraction in the auroral E region.

• OSTI ID: 5444365
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 95:A9; ISSN JGREA; ISSN 0148-0227
• 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 ZONES
BACKSCATTERING
COMPARATIVE EVALUATIONS
E REGION
EARTH ATMOSPHERE
ELECTROMAGNETIC RADIATION
ELECTRON DENSITY
EVALUATION
IONIZATION
IONOSPHERE
MEASURING INSTRUMENTS
PLANETARY IONOSPHERES
RADAR
RADIATIONS
RADIOWAVE RADIATION
RANGE FINDERS
REFRACTION
SCATTERING
VISIBLE RADIATION