Effects of high-latitude atmospheric gravity wave disturbances on artificial HF radar backscatter

A. Senior (1) , M. J. Kosch (1) , T. K. Yeoman (2) , M. T. Rietveld (3) , I. W. Mccrea (4)

1 Dept. of Communication Systems
2 Department of Physics and Astronomy [Leicester]
3 EISCAT Scientific Association
4 RAL Space - Space Science and Technology Department [Didcot]

Observations of HF radar backscatter from artificial field-aligned irregularities in an ionosphere perturbed by travelling disturbances due to atmospheric gravity waves are presented. Some features of the spatio-temporal structure of the artificial radar backscatter can be explained in terms of the distortion of the ionosphere resulting from the travelling disturbances. The distorted ionosphere can allow the HF pump wave to access upper-hybrid resonance at larger distances from the transmitter than are normally observed and can also prevent the pump wave reaching this resonance at close distances. The variation in altitude of the irregularities sometimes results in a significant variation in the elevation angle of arrival of the backscattered signal at the radar implying that the radar "sees" a target moving in altitude. We suggest that this may be evidence of off-orthogonal scattering from the irregularities.

Domaines: Océan, Atmosphère; Sciences de la Terre

A. Senior, M. J. Kosch, T. K. Yeoman, M. T. Rietveld, I. W. Mccrea. Effects of high-latitude atmospheric gravity wave disturbances on artificial HF radar backscatter. Annales Geophysicae, 2006, 24 (9), pp.2347-2361. ⟨hal-00318164⟩