Nightside studies of coherent HF Radar spectral width behaviour, Ann

• Main Authors: E. E. Woodfield, J. A. Davies, M. Lester, T. K. Yeoman, P. Eglitis, M. Lockwood
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: EISCAT
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.694.8391; http://www.eiscat.rl.ac.uk/Members/mike/publications/pdfs/2002/211_Woodfieldetal_ang-20-1399.pdf

Abstract. A previous case study found a relationship be-tween high spectral width measured by the CUTLASS Fin-land HF radar and elevated electron temperatures observed by the EISCAT and ESR incoherent scatter radars in the post-midnight sector of magnetic local time. This paper expands that work by briefly re-examining that interval and looking in depth at two further case studies. In all three cases a re-gion of high HF spectral width (> 200 ms−1) exists poleward of a region of low HF spectral width (< 200 ms−1). Each case, however, occurs under quite different geomagnetic con-ditions. The original case study occurred during an interval with no observed electrojet activity, the second study dur-ing a transition from quiet to active conditions with a clear band of ion frictional heating indicating the location of the flow reversal boundary, and the third during an isolated sub-