共查询到20条相似文献,搜索用时 17 毫秒
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Sneha A. Gokani Rajesh Singh S. Tulasi Ram K. Venkatesham B. Veenadhari Sandeep Kumar R. Selvakumaran 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2018,61(7):1909-1918
The source region and propagation mechanism of low latitude whistlers (Geomag. lat. <30°) have puzzled scientific community for last many decades. In view of recent reports, there is consensus on the source region of low latitude whistlers in the vicinity of the conjugate point. But the plausible conditions of ionospheric medium through which they travel are still uncertain. In addition to that, the whistlers in daytime are never observed at geomagnetic latitudes less than 20°. Here, for the first time, we present a rare observations of whistlers during sunlit hours from a very low-latitude station Allahabad (Geomag. Lat: 16.79°N, L = 1.08) in India on 04 February 2011. More than 90 whistlers are recorded during 1200–1300 UT during which the whole propagation path from lightning source region to whistler observation site is under sunlit. The favorable factors that facilitated the whistlers prior to the sunset are investigated in terms of source lightning characteristics, geomagnetic and background ionospheric medium conditions. The whistler activity period was found to be geomagnetically quiet. However, a significant suppression in ionospheric total electron content (TEC) compared to its quiet day average is found. This shows that background ionospheric conditions may play a key role in low latitude whistler propagation. This study reveals that whistlers can occur under sunlit hours at latitudes as low as L = 1.08 when the source lightning and ionospheric medium characteristics are optimally favorable. 相似文献
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几年以前,一篇名为《飞船即将坠毁》的文章出现在各种报刊上,文章讲述了一个感人的故事:1967年4月23日,苏联航天员科马罗夫在执行完联盟一号飞船飞行任务后,发现用于飞船着陆时减速的降落伞因故障无法打开,联盟一号将在两小时后坠毁。在科马罗夫生命的最后两小时,他平静的向地面指挥中心作了汇报,并与他老母亲、妻子和女儿挥泪诀别。最后全苏联人民在电视直播中,看到了科马罗夫因飞船坠毁而壮烈牺牲,整篇文章情节感人、催人泪下。 相似文献
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<正>哈罗!如果读者看到这篇日记,我猜想,读者已经对"火星500"项目有了大致的了解,对于我们的第一天,我想写一些我们的训练及在隔离设备中的感受。对我来说,最重要的一点是:发现太空领域与研究领域是两码事。正如读者知道的那样,我的学科背景是工业领域,尤其是电子工业。太空是一个几乎不能到达的遥远目标。今天,我能记得的近期经历是:"我两天前在卡纳维拉 相似文献
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1947年,美苏开始了冷战时期的军事对峙。双方关系十分紧张,都担心对方进行入侵,包括空中入侵。在这一时期,前苏联防空部队曾多次发现.有不明飞行物光顾前苏联领空。前苏军不得不进行空中拦截.但均以失败告终。日前,西方媒体披露了前苏联有关遭遇飞碟的内幕。 相似文献
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S.N. Kuznetsov L.L. Lazutin M.I. Panasyuk L.I. Starostin Yu.V. Gotseliuk N. Hasebe K. Sukurai M. Hareyama 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2009
It is a case study of a chain of three magnetic storms with a special attention to the particle dynamics based on CORONAS-F and SERVIS-1 low altitude satellite measurements. Solar proton penetration inside the polar cap and inner magnetosphere and dynamics at different phases of the magnetic storms was studied. We found, that solar protons were captured to the inner radiation belt at the recovery phase of the first and the second magnetic storms and additionally accelerated during the last one. No evidence of sudden commencement (SC) particle injection was found. Enhanced solar proton belt intensity with small pitch angles decreased slowly during satellite orbits for 30 days until the next magnetic storm. Then in 20–30 h we registered strong precipitation of these protons followed by the trapped proton flux dropout. Intensity decrease was more pronounced at lower altitudes and higher particle energies. 相似文献
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Gustavo A. Mansilla Marta M. Zossi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2012
This paper reports the response of the ionosphere–thermosphere system to an intense geomagnetic storm. For that, data taken by instruments on board Dynamic Explorer 2 at heights of the F2-layer (molecular nitrogen N2 and atomic oxygen O compositions, neutral temperature Tg and electron density Ne) were used. The ionospheric response is characterized by a negative storm effect expanding from mid–high to low latitude. It is observed during this severe geomagnetic storm that negative effects were caused mainly by an increase in molecular nitrogen composition N2 and almost no changes in atomic oxygen composition O. 相似文献
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正新闻:"18日凌晨后,东方航空欢迎开机。"——北京时间1月17日晚9时起飞的东航上海—洛杉矶MU577航班上,响起了不一样的客舱广播。乘坐飞机时需要将手机关机,这个"老规矩"迎来解禁,多家航空公司于近日陆续宣布乘机时可以使用手机。解读:飞机上终于能玩手机了!多年夙愿在卫星的帮助下向前跨出了实质性的一大步。想要在飞行中使用手机主要有两种实现途径,一种是地空通信——需要 相似文献