High resolution observations of spectral width features associatedwith ULF wave signatures in artificial HF radar backscatter

International audience The EISCAT high power heating facility at Tromsø, northern Norway, has been utilised to generate artificial radar backscatter in the fields of view of the CUTLASS HF radars. It has been demonstrated that this technique offers a means of making very accurate and high resolution...

Full description

Bibliographic Details
Main Authors: Wright, D. M., Yeoman, T. K., Baddeley, L. J., Davies, J. A., Dhillon, R. S., Lester, M., Milan, S. E., Woodfield, E. E.
Other Authors: Department of Physics and Astronomy Leicester, University of Leicester
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2004
Subjects:
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Norway
Tromsø
EISCAT
Northern Norway
Online Access:https://hal.science/hal-00317214
https://hal.science/hal-00317214/document
https://hal.science/hal-00317214/file/angeo-22-169-2004.pdf
Description
Summary:International audience The EISCAT high power heating facility at Tromsø, northern Norway, has been utilised to generate artificial radar backscatter in the fields of view of the CUTLASS HF radars. It has been demonstrated that this technique offers a means of making very accurate and high resolution observations of naturally occurring ULF waves. During such experiments, the usually narrow radar spectral widths associated with artificial irregularities increase at times when small scale-sized (high m -number) ULF waves are observed. Possible mechanisms by which these particle-driven high- m waves may modify the observed spectral widths have been investigated. The results are found to be consistent with Pc1 (ion-cyclotron) wave activity, causing aliasing of the radar spectra, in agreement with previous modelling work. The observations also support recent suggestions that Pc1 waves may be modulated by the action of longer period ULF standing waves, which are simultaneously detected on the magnetospheric field lines. Drifting ring current protons with energies of ? 10keV are indicated as a common plasma source population for both wave types. Key words. Magnetospheric physics (MHD waves and instabilities) ? Space plasma physics (wave-particle interactions) ? Ionosphere (active experiments)

Similar Items