Ionospheric scintillation observations over Kenyan region - Preliminary results

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• 作者：O.J. Olwendo^a ; ^{j.olwendo@pu.ac.ke" class="auth_mail" title="E-mail the corresponding author} ; ^{castrajoseph@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; Yu Xiao^b ; ^{earings322@163.com" class="auth_mail" title="E-mail the corresponding author} ; Ou Ming^b
• 关键词：Ionosphere ; Scintillation ; Low-latitude ; Plasma depletions
• 刊名：Advances in Space Research
• 出版年：2016
• 出版时间：1 November 2016
• 年：2016
• 卷：58
• 期：9
• 页码：1739-1745
• 全文大小：1389 K

文摘

Ionospheric scintillation refers to the rapid fluctuations in the amplitude and phase of a satellite signal as it passes through small-scale plasma density irregularities in the ionosphere. By analyzing ionospheric scintillation observation datasets from satellite signals such as GPS signals we can study the morphology of ionospheric bubbles. At low latitudes, the diurnal behavior of scintillation is driven by the formation of large-scale equatorial density depletions which form one to two hours after sunset via the Rayleigh–Taylor instability mechanism near the magnetic equator. In this work we present ionospheric scintillation activity over Kenya using data derived from a newly installed scintillation monitor developed by CRIRP at Pwani University (39.78°E, 3.24°S) during the period August to December, 2014. The results reveal the scintillation activity mainly occurs from post-sunset to post-midnight hours, and ceases around 04:00 LT. We also found that the ionospheric scintillation tends to appear at the southwest and northwest of the station. These locations coincide with the southern part of the Equatorial Ionization Anomaly crest over Kenya region. The occurrence of post-midnight L-band scintillation events which are not linked to pre-midnight scintillation observations raises fundamental question on the mechanism and source of electric fields driving the plasma depletion under conditions of very low background electron density.