Very high latitude F-region irregularities observed by HF-radar backscatter
In February and March, 1982, a coherent scatter HF radar was operated from Cleary, Alaska to observe 7- to 15-m wavelength F-region plasma irregularities near the poleward edge of the auroral zone and in the polar cap. The radar operated for five days from February 25 to March 1 and produced approximately 700,000 Doppler spectra during that time. Of those nearly 700,000 spectra, approximately 10% showed backscattered power 3 dB or more above the noise level. A ray tracing technique using electron densities determined by the Chatanika incoherent scatter radar was used to predict locations where the HF waves were approximately normal to the magnetic field. If those locations were also to contain small scale electron density structure, then one would expect them to backscatter the HF waves. Several comparisons were made between predicted and observed locations of radiowave backscatter and excellent agreement was obtained. In addition, comparisons of the Doppler velocities observed by the coherent scatter HF radar and those observed by the Chatanika radar showed good agreement, suggesting that the plasma irregularities observed by the HF radar drift with the ambient plasma. In addition, average vector velocities calculated for the entire 5-day period show a flow pattern consistent with polar cap convection models. This again indicates that the irregularities drift with the plasma, as is predicted by a number of theories of F-region plasma irregularities. In the summer of 1983, the research program begun with those measurements will be continued with a steerable phased-array HF radar located at Goose Bay, Labrador, that will view the same ionospheric region as does the Sondre Stromfjord incoherent scatter radar.
- Research Organization:
- Applied Physics Laboratory, The Johns Hopkins University, Laurel, Maryland 20707
- OSTI ID:
- 5667907
- Journal Information:
- Geophys. Res. Lett.; (United States), Vol. 10:9
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
GENERAL PHYSICS
F REGION
ELECTRON DENSITY
AURORAL ZONES
BACKSCATTERING
DOPPLER EFFECT
FLUCTUATIONS
PLASMA DRIFT
POLAR REGIONS
RADAR
EARTH ATMOSPHERE
IONOSPHERE
MEASURING INSTRUMENTS
PLANETARY IONOSPHERES
RANGE FINDERS
SCATTERING
VARIATIONS
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena