1. Coherent EISCAT Svalbard Radar spectra from the dayside cusp/cleft and their implications for transient field-aligned currents
- Author
-
M. H. Rees, Joran Moen, D. A. Lorentzen, Betty Lanchester, T. S. Trondsen, K. J. F. Sedgemore-Schulthess, and Mike Lockwood
- Subjects
Atmospheric Science ,Incoherent scatter ,Soil Science ,Astrophysics ,Aquatic Science ,Oceanography ,F region ,Spectral line ,law.invention ,Photometry (optics) ,Geochemistry and Petrology ,law ,Earth and Planetary Sciences (miscellaneous) ,Radar ,Earth-Surface Processes ,Water Science and Technology ,Physics ,Cusp (singularity) ,Ecology ,Paleontology ,Forestry ,Geophysics ,Photometer ,Space and Planetary Science ,Physics::Space Physics ,Electron temperature - Abstract
Naturally enhanced incoherent scatter spectra from the vicinity of the dayside cusp/cleft, interpreted as being due to plasma turbulence driven by short bursts of intense field-aligned current, are compared with high-resolution narrow-angle auroral images and meridian scanning photometer data. Enhanced spectra have been observed on many occasions in association with nightside aurora, but there has been only one report of such spectra seen in the cusp/cleft region. Narrow-angle images show considerable change in the aurora on timescales shorter than the 10-s radar integration period, which could explain spectra observed with both ion lines simultaneously enhanced. Enhanced radar spectra are generally seen inside or beside regions of 630-nm auroral emission, indicative of sharp F region conductivity gradients, but there appears also to be a correlation with dynamic, small-scale auroral forms of order 100 m and less in width.
- Published
- 1999