Mid-latitude frequency spread and its association with small scale ionospheric stratifications |
| |
| Institution: | 1. Student Research Committee, Faculty of Medical Sciences, Babol University of Medical Sciences, Babol, Mazandaran, Iran;2. Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Mazandaran, Iran;3. Neuroscience Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Mazandaran, Iran;4. Department of Pharmacology, Faculty of Medical Sciences, Babol University of Medical Sciences, Babol, Mazandaran, Iran;5. Department of Physiology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran;1. Institute of Technical Thermodynamics and Center of Smart Interfaces, Technische Universität Darmstadt, 64287 Darmstadt, Germany;2. Research Interfacial Technology, Evonik Nutrition & Care GmbH, 45127 Essen, Germany;3. Physics at Interfaces, Max Planck Institute for Polymer Research, 55128 Mainz, Germany;1. Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, Canada M5G 1X5;2. Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S 1A8;3. Department of Physiology, University of Toronto, Toronto, ON, Canada M5S 1A8;4. Center for Brain Science, Department of Physics, Harvard University, Cambridge, MA 02138, United States;1. Department of Electrical Engineering and Computer Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea;2. Information and Communication Engineering Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea;1. Parkland Health & Hospital System, Dallas, TX;2. Department of Psychiatry, The University of Texas Southwestern Medical Center, Dallas, TX;3. Office of the Clinical Director, National Institute of Mental Health, National Institutes of Health, Bethesda, MD;4. Abigail Wexner Research Institute at Nationwide Children''s Hospital, Columbus, OH;5. Pediatrics, Psychiatry & Behavioral Health, The Ohio State University College of Medicine, Columbus, OH |
| |
| Abstract: | A variety of ground based radio techniques have provided new information relating to the nature of mid-latitude F-region irregularities responsible for frequency spreading on ionograms. Firstly, an analysis of ionograms covering a restricted frequency band indicates that frequency spreading is primarily caused by duplicate traces which are often unresolved in group path on standard ionograms. Furthermore, where angle of arrival information is available, the duplicate traces are shown to represent reflections from markedly different directions and the spread in critical frequencies is therefore indicative of a horizontal gradient in the peak electron density over a scale size of the order of many tens of kilometres. Secondly, the individual duplicate traces themselves are shown to comprise quasi-horizontal trace (QHT) segments which are unresolved on conventional ionograms and contribute to the diffuse appearance of spread-F traces on those ionograms. Difficulties in attributing these observations to the widely held view that scattering from small scale structures is the causative mechanism are discussed. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
