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On the radar frequency dependence of polar mesosphere summer echoes

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Earth and Planetary Physics 2020年第6期4卷 571-578页

作者： ShuCan Ge HaiLong Li Lin Meng MaoYan Wang Tong Xu Safi Ullah Abdur Rauf Abdel Hannachid School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China National Key Laboratory of Electromagnetic Environment China Research Institute of Radio Wave PropagationQingdao 266107China Department of Meteorology Stockholm UniversitySE-106-91StockholmSweden

polar mesosphere summer echoes(PMSEs)are very strong radar echoes in the polar mesopause in local *** we present the frequency dependence of the volume reflectivity and the effect of energetic particle precipitation on modulated PMSEs by using PMSEs observations carried out by European Incoherent SCATter(EISCAT)heating equipment simultaneously with very high frequency(VHF)radar and ultra high frequency(UHF)radar on 12 July *** to the experimental observations,the PMSEs occurrence rate at VHF was much higher than that at UHF,and the altitude of the PMSEs maximum observed at VHF was higher than that at *** regions were observed by VHF radar between high energetic particle precipitation and the *** addition,highfrequency heating had a very limited impact on PMSEs when the UHF electron density was enhanced because of energetic particle *** addition,an updated qualitative method was used to study the relationship between volume reflectivity and *** volume reflectivity was found to be inversely proportional to the fourth power of radar *** theoretical and experimental results provide a definitive data foundation for further analysis and investigation of the physical mechanism of PMSEs.

关键词： polar mesosphere summer echoes artificial electron heating volume reflectivity energetic particle precipitation

Characteristic analysis of layered PMSEs measured with different elevation angles at VHF based on an experimental case

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Earth and Planetary Physics 2021年第1期5卷 42-51页

作者： ShuCan Ge HaiLong Li Bin Xu Tong Xu Lin Meng MaoYan Wang Abdel Hannachi MengYan Zhu Lina Broman Safi Ullah Abdur Rauf School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China National Key Laboratory of Electromagnetic Environment China Research Institute of Radiowave PropagationQingdao 266107China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China Department of Meteorology Stockholm UniversityStockholm SE-106-91Sweden

polar mesosphere summer echoes(PMSEs)are very strong radar echoes observed at altitudes near the polar summer *** of the essential properties of these radar echoes is that they can give useful diagnostic information about the physics of the scattering *** this paper,the related characteristics of PMSEs measured with the European Incoherent SCATter Very High Frequency(EISCAT VHF)224 MHz radar on 13–15 July 2010 are studied at different elevation angles from 78°to 90°.It is found that the PMSEs peak power and strongest PMSEs average power occur at the same elevation *** interesting is that the strongest PMSEs occur at off-vertical angles when a PMSEs has a layered(multilayer)*** reflection may have more significant effects on PMSEs when there are double or multilayer *** explanations regarding these observations are discussed.

关键词： polar mesosphere summer echoes off-vertical angles layered structure

Exploring the occurrence rate of PMSE-Es by Digisonde at Tromsø

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Earth and Planetary Physics 2021年第2期5卷 187-195页

作者： HaiLong Li ShuCan Ge Lin Meng MaoYan Wang Abdur Rauf Safi Ullah School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610054China National Key Laboratory of Electromagnetic Environment China Research Institute of Radiowave PropagationQingdao 266107China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China

polar mesosphere summer echoes(PMSE)are observed simultaneously with Digisonde and EISCAT VHF *** phenomenon of irregular Es layers is called PMSE-like or PMSE-Es(polar mesosphere summer echoes-Es)and has some relationship with real *** this paper,the characteristics of irregular Es layers at 80–100 km were observed by Digisonde at Tromsøduring 2003–2014 are statistically analyzed with *** diurnal,day-to-day and year-to-year variations and discrepancies of occurrence rate between PMSE and PMSE-Es are compared with the statistical results observed by Esrange MST radar(ESRAD),and the reasons are *** results show that the trends in the occurrence rate of PMSE-Es are similar to the trends in the occurrence rate of PMSE,but there are some notable *** occurrence rate of PMSE-Es is much lower than the occurrence rate of *** minimum value of PMSE-Es appears 1–2 hours earlier than the minimum value of the PMSE occurrence rate,while PMSE-Es appear earlier than PMSE in the *** addition,there is a significant positive correlation between the annual average occurrence rates of PMSE and *** is a relatively important occurrence in the polar *** of its characteristics can provide new ideas and methods for studying the formation mechanism of PMSE.

关键词： polar mesosphere summer echoes Digisonde EISCAT VHF radar PMSE-Es Esrange MST radar

Study on the Relation Between the Reflectivity and Frequency in Dusty Plasma of the polar summer Mesopause

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Plasma Science and Technology 2009年第3期11卷 279-282页

作者：李海龙吴健黄际英王茂琰 School of Science Xidian University School of Physical Electronics University of Electronic Science and Technology of China National Key Laboratory of Electromagnetic Environment China Research Institute of Radiowave Propagation

Relation between the volume reflectivity and frequency in view of the polar mesosphere summer echoes （PMSE） is studied using the small-scale structure of electron density caused by charged dust particles. A theoretical expression for the radar volume reflectivity is derived, which agrees with the statistical result. Both the theoretical and statistical results are confirmed with the data obtained from simultaneous observations at three frequencies. Hence the small-scale structure caused by charged dust particles may be a useful tool for the study on the generation mechanism of PMSE.

关键词： polar mesosphere summer echoes reflectivity dusty plasma dust