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Case study of an Equatorial Plasma Bubble Event investigated by multiple ground-based instruments at low latitudes over China

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Earth and Planetary Physics 2021年第5期5卷 435-449页

作者： LongChang Sun JiYao Xu YaJun Zhu Wei Yuan xiukuan zhao State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China

Observational evidence is insufficient to understand how equatorial plasma bubbles(EPBs)form over low *** mechanism of plasma-density enhancement(formation of"plasma blobs")at low latitudes is in *** this paper,we use data from multiple ground-based instruments(one all-sky airglow imager,five digisondes,and one Fabry–Perot interferometer)to investigate the evolution of an EPB event that occurred at low latitudes over China on the night of 06 December 2015(06-Dec-2015).We provide observational evidence that an enhanced equatorward wind most likely induced by a substorm could have initiated the Rayleigh–Taylor instability(RTI)that destabilized several EPB depletions in an upwelling region of a large-scale wave-like structure(LSWS)in the bottomside *** EPB depletions were forced to surge poleward,from nearly 10°to 19°magnetic latitude,two hours before ***-scale bifurcations evolved rapidly from tips of airglow depletions by a secondary E×B instability when the aforementioned substorm-induced southwestward wind blew *** the growth phase of the EPB depletions,a westward polarization electric field inside the LSWS is likely to have compressed plasma downward,inducing the two airglow-type blobs observed in the bottomside ionosphere,by a mechanism of LSWS-blob connection that we *** also provide observational evidence of brightness airglow *** find that an enhanced poleward wind associated with a passing-by brightness wave(BW)is likely to have transported plasma to fill the airglow depletions,which finally evolved into brightness airglow *** study investigates the physical processes accompanied by the EPB event and those two-airglow blobs observed at low-latitudes over China.

关键词： Equatorial Plasma Bubble plasma blobs Rayleigh–Taylor instability secondary E×B instability nighttime brightness wave large-scale wave-like structure enhanced equatorward(poleward)wind

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Onset location of scintillation-producing spread-F plume over Sanya

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Science China Earth Sciences 2016年第8期59卷 1692-1699页

作者： ZHENG JianChang HUANG zhaoGuo WU Zhi HAO XiQing JI JiaLun NING BaiQi HU LianHuan zhao xiukuan LI GuoZhu Key Laboratory of Earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and Geophysics Chinese Academy of Sciences

Equatorial spread-F (ESF) backscatter plumes are often observed in radar range-time-intensity (RTI) maps at low latitude. Except case studies, few statistical investigations on the onset locations of scintillation-producing ESF plumes at given sites have been conducted. In this study, a statistical analysis is carried out on onset locations of ESF backscatter plumes observed at a low-latitude location Sanya (18.4°N, 109.6°E; dip lat 12.8°N) during equinoctial months of 2013. By employing a tracing method to locate backscatter plumes, we estimate the onset longitudes of periodic plumes obtained from the Sanya VHF radar five-beam steering measurements. The results show that the inter-plume distances (in longitude) are mostly confined within 200–600 km, and the ESF plumes producing ionospheric scintillations over Sanya are almost exclusively generated at the longitudes of 94°–110°E. The results indicate the necessity to monitor ESF plume initial generation in the longitude region of 94°–110°E to better understand the day-to-day variability in the occurrence of ionospheric scintillations over Sanya.

关键词： Equatorial spread-F Backscatter plume Onset location VHF radar Zonal drift

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First results of optical meteor and meteor trail irregularity from simultaneous Sanya radar and video observations

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Earth and Planetary Physics 2018年第1期2卷 15-21页

作者： GuoZhu Li BaiQi Ning Ao Li SiPeng Yang xiukuan zhao BiQiang zhao WeiXing Wan Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Institutions of Earth Science Chinese Academy of SciencesBeijing 100029China Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Meteoroids entering the Earth's atmosphere can create meteor trail irregularity seriously disturbing the background ionosphere. Although numerous observations of meteor trail irregularities were performed with VHF/UHF coherent scatter radars in the past, no simultaneous radar and optical instruments were employed to investigate the characteristics of meteor trail irregularity and its corresponding meteoroid. By installing multiple video cameras near the Sanya VHF radar site, an observational campaign was conducted during the period from November 2016 to February 2017. A total of 242 optical meteors with simultaneous non-specular echoes backscattered from the plasma irregularities generated in the corresponding meteor trails were identified. A good agreement between the angular positions of non-specular echoes derived from the Sanya radar interferometer and those of optical meteors was found,validating that the radar system phase offsets have been properly calibrated. The results also verify the interferometry capability of Sanya radar for meteor trail irregularity observation. The non-specular echoes with simultaneous optical meteors were detected at magnetic aspect angles greater than ~78°. Based on the meteor visual magnitude estimated from the optical data, it was found that the radar nonspecular echoes corresponding to brighter meteors survived for longer duration. This could provide observational evidence for the significance of meteoroid mass on the duration of meteor trail irregularity. On the other hand, the simultaneous radar and video common-volume observations showed that there were some cases with optical meteors but without radar non-specular echoes. One possibility could be that some of the optical meteors appeared at extremely low altitudes where meteor trail irregularities rarely occur.

关键词： meteor ionosphere radar non-specular echo

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流星不均匀体多波段探测系统与初步观测结果

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地球与行星物理论评（中英文） 2024年第3期55卷 292-307页

作者：李怡李国主解海永孙文杰胡连欢武志陈文志黄照国吴宝元赵秀宽余优常首民宁百齐刘立波中国科学院地质与地球物理研究所、地球与行星物理重点实验室北京100029 中国科学院地质与地球物理研究所、北京空间环境国家野外科学观测研究站北京100029 中国科学院大学、地球与行星科学学院北京100049 中国科学院地质与地球物理研究所、黑龙江漠河地球物理国家野外科学观测研究站北京100029

流星体注入地球空间给地球带来外部物质并影响地球空间环境.为了探知流星体对空间环境的影响,需获取不同类型流星体及其在地球大气中产生系列现象的特征.本文介绍近期研制建设的流星不均匀体多波段探测系统.该系统设计采用光学大范围成... 详细信息

流星体注入地球空间给地球带来外部物质并影响地球空间环境.为了探知流星体对空间环境的影响,需获取不同类型流星体及其在地球大气中产生系列现象的特征.本文介绍近期研制建设的流星不均匀体多波段探测系统.该系统设计采用光学大范围成像和无线电相控阵雷达与双基地全天空雷达主动探测,实现对不同尺寸流星体坠入地球高空大气/电离层后的烧蚀、蒸发和电离到流星不均匀体产生与演化等系列过程探测.通过开发多种探测模式和相应的数据分析反演算法,获取流星体速度、质量、成分和星际来源、流星等离子体头和等离子体尾迹不均匀体的空间精细结构与演化以及低电离层“瞬时”风场等多参量信息.利用该系统观测数据,对流星体及其产生的流星等离子体头、等离子体尾迹场向和非场向不均匀体、流星闪耀和尘埃不均匀体以及电离层不均匀体等开展了初步研究.

关键词：流星流星体流星尾迹不均匀体电离层不均匀体探测系统

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An Effective Active Semi-supervised Learning Method Based on Manifold Regularization

An Effective Active Semi-supervised Learning Method Based on...

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中国科学院地质与地球物理研究所2013年度（第13届）...

作者： xiukuan zhao Baiqi Ning Gangbing Song Key Laboratory of Ionospheric Environment Institute of Geology and GeophysicsChinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and GeophysicsChinese Academy of Sciences Department of Mechanical Engineering University of Houston

Conventional artificial intelligent methods such as neural network and SVM use only labeled data (feature/label pairs) for *** instances are often difficult,expensive,or time consuming to obtain. To use a large amount of unlabeled data together with labeled data to build better models,we proposed an active semi-supervised learning method based on the pool query active learning and mamfold regularization semi-supervised *** this paper,the effectiveness of the method was verified by its application to a synthetic data set and three real world classification *** experimental results showed that employing our active semi-supervised learning method can significantly reduce the need for labeled training instances.

关键词： Semi-supervised learning active learning LapSVM A-LapSVM

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A prediction model of short-term ionospheric fo F2 based on Ada Boost

A prediction model of short-term ionospheric fo F2 based on ...

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中国科学院地质与地球物理研究所2014年度（第14届）...

作者： xiukuan zhao Baiqi Ning Libo Liu Gangbing Song Key Laboratory of Ionospheric Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and Geophysics Chinese Academy of Sciences Department of Mechanical Engineering University of Houston School of Civil Engineering Dalian University of Technology

In this paper, the Ada Boost-BP algorithm is used to construct a new model to predict the critical frequency of the ionospheric F2-layer(fo F2) one hour ahead. Different indices were used to characterize ionospheric diurnal and seasonal variations and their dependence on solar and geomagnetic activity. These indices, together with the current observed fo F2 value, were input into the prediction model and the fo F2 value at one hour ahead was output. We analyzed twenty-two years’ fo F2 data from nine ionosonde stations in the East-Asian sector in this work. The first eleven years’ data were used as a training dataset and the second eleven years’ data were used as a testing dataset. The results show that the performance of Ada Boost-BP is better than those of BP Neural Network(BPNN),Support Vector Regression(SVR) and the IRI model. For example, the Ada Boost-BP prediction absolute error of fo F2 at Irkutsk station(a middle latitude station) is 0.32 MHz, which is better than 0.34 MHz from BPNN, 0.35 MHz from SVR and also significantly outperforms the IRI model whose absolute error is 0.64 MHz. Meanwhile, Ada Boost-BP prediction absolute error at Taipei station from the low latitude is 0.78 MHz, which is better than 0.81 MHz from BPNN, 0.81 MHz from SVR and 1.37 MHz from the IRI ***, the variety characteristics of the Ada Boost-BP prediction error along with seasonal variation, solar activity and latitude variation were also discussed in the paper.

关键词： Ada Boost Ionosphere fo F2 Short-term prediction

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Innovative Data Fusion Enabled Structural Health Monitoring Approach

Innovative Data Fusion Enabled Structural Health Monitoring ...

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中国科学院地质与地球物理研究所2014年度（第14届）...

作者： xiukuan zhao Ruolin Wang Haichang Gu Gangbing Song Y.L.Mo Key Laboratory of Ionospheric Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing National Observatory of Space Environment Institute of Geology and Geophysics Chinese Academy of Sciences School of Civil Engineering Wuhan University Department of Mechanical Engineering University of Houston School of Civil Engineering Dalian University of Technology Department of Civil and Environmental Engineering University of Houston

Piezoceramic-based active sensing is a useful approach to structural health monitoring. his approach oten involves a large number of distributed piezoceramic transducers. It may be confusing to incorporate each sensor data. It is desired to develop an automated health monitoring approach to obtain a comprehensive and accurate health monitoring result by simultaneously interpreting data from all sensors. In this paper, an innovative data fusion enabled structural health monitoring(SHM) approach based on the Dempster-Shafer(D-S) evidence theory is proposed to obtain comprehensive SHM results for a distributed sensor network in a civil infrastructure. Considering that evidence from multiple diferent information sources(sensor data) has diferent levels of signiicance, not all evidence is equivalently efective for the inal decision. A weighted fusion damage index(WFDI) is proposed to perform damage identiication based on the authors’ recently developed piezoceramic-based smart aggregates. Experimental data of a two-story concrete frame was used to study the efectiveness of the proposed weighted fusion damage index. Analyses show that the proposed weighted fusion damage index can reveal the damage status of diferent areas of the frame. he results are consistent with the visual inspection of the cracks on the concrete frame.

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基于GNSS观测的全球赤道等离子体泡对太阳和地磁活动及季节依赖特征

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地球物理学报 2023年第7期66卷 2703-2712页

作者：赵秀宽李国主胡连欢解海永孙文杰李怡宁百齐刘立波中国科学院地质与地球物理研究所地球与行星物理重点实验室北京100029 中国科学院地质与地球物理研究所黑龙江漠河地球物理国家野外科学观测研究站北京100029 中国科学院地质与地球物理研究所北京空间环境国家野外科学观测研究站北京100029 中国科学院地质与地球物理研究所国家地球系统科学数据中心——地球物理分中心北京100029 中国科学院大学地球与行星科学学院北京100049

赤道等离子体泡是在磁赤道和低纬地区一种通常发生在夜间的大尺度电离层不规则结构.本文利用2010—2021年全球低纬地区GNSS TEC监测仪长期观测数据,分析了赤道等离子体泡对太阳和地磁活动及季节的依赖特征.结果表明,全球每个经度区赤道... 详细信息

赤道等离子体泡是在磁赤道和低纬地区一种通常发生在夜间的大尺度电离层不规则结构.本文利用2010—2021年全球低纬地区GNSS TEC监测仪长期观测数据,分析了赤道等离子体泡对太阳和地磁活动及季节的依赖特征.结果表明,全球每个经度区赤道等离子体泡发生率与太阳活动都显著正相关,赤道等离子体泡的日发生率与F107指数相关系数接近0.70.经度-60°~-30°在赤道等离子体泡高发月份的日落后发生率与F107的相关关系有明显的饱和效应.在季节变化方面,经度-60°~-30°赤道等离子体泡主要发生在1—3月和10—12月,其他经度主要发生在分季.不同经度区赤道等离子体泡日落后发生率季节不对称性存在显著区别,在太阳活动上升期,经度-60°~-30°的10—12月发生率明显高于1—3月;在太阳活动下降期,0°~180°经度区3月分季高于9月分季.此外,地磁扰动对产生赤道等离子体泡主要是抑制作用,特别是在太阳活动高年、分季.

关键词：电离层赤道等离子体泡季节变化太阳活动地磁活动

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地球空间环境的野外科学观测研究

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中国科学院院刊 2019年第6期34卷 726-733页

作者：宁百齐李国主胡连欢赵秀宽中国科学院地质与地球物理研究所北京空间环境国家野外科学观测研究站

地球空间包括地球中高层大气、电离层和磁层,其环境变化深刻影响着人类生活,如空间灾害性事件的发生,可能危害地面电网安全,造成星地无线电通讯中断。在科技部、国家自然科学基金委和中国科学院等部门支持下,北京空间环境国家野外科学... 详细信息

地球空间包括地球中高层大气、电离层和磁层,其环境变化深刻影响着人类生活,如空间灾害性事件的发生,可能危害地面电网安全,造成星地无线电通讯中断。在科技部、国家自然科学基金委和中国科学院等部门支持下,北京空间环境国家野外科学观测研究站通过研制和发展一批具有国际先进水平的观测仪器,建立了电离层、中高层大气和地磁等多学科综合观测台链,并开发成功新的探测模式和诊断技术,实现对我国上空多种空间环境参量的科学观测,揭示其区域特征和空间精细结构与变化,推动数据服务于原创科学研究和空间天气预报保障任务。基于观测数据,通过发展理论模式,采用数据分析与数值模拟相结合等研究方法,系统研究了大气层-电离层耦合、磁层-电离层耦合和太阳辐射的光电离光化学3类最为重要的驱动过程对电离层变化性的影响和控制作用。

关键词：地球空间环境探测模式电离层导航通讯

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北京上空中小尺度电离层扰动特征

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地球物理学报 2023年第12期66卷 4828-4839页

作者：胡连欢李国主宁百齐朱正平蓝加平孙文杰郝喜庆常首民吴宝元赵秀宽解海永李怡中国科学院地质与地球物理研究所北京空间环境国家野外科学观测研究站北京100029 中国科学院地质与地球物理研究所中国科学院地球与行星物理重点实验室北京100029 中国科学院大学地球与行星科学学院北京100049 中南民族大学电子信息工程学院武汉430074 中国科学院地质与地球物理研究所黑龙江漠河地球物理国家野外科学观测研究站北京100029

本文采用电离层测高仪数据对北京上空中小尺度电离层扰动进行了事例分析和统计研究.利用PDI电离层测高仪的快速扰动探测数据,分析了2017年11月13日北京上空典型的中小尺度电离层扰动事件.结果表明,电离层测高仪直接观测的电离层频高图上... 详细信息

本文采用电离层测高仪数据对北京上空中小尺度电离层扰动进行了事例分析和统计研究.利用PDI电离层测高仪的快速扰动探测数据,分析了2017年11月13日北京上空典型的中小尺度电离层扰动事件.结果表明,电离层测高仪直接观测的电离层频高图上的V形(或U形)下降结构,是中等尺度电离层扰动的一种“显式”特征.小尺度电离层扰动主要出现于较低的高度,并不伴随着电离层频高图上显著的异常结构.通过统计2010—2021年电离层频高图数据中的电离层异常描迹事件,分析了北京上空中等尺度电离层扰动的发生率特征.以这些特殊描迹为特征的电离层扰动主要是白天现象,且冬季的发生率显著高于其他季节.其发生率与太阳活动呈反相关,即太阳活动较强时中等尺度电离层扰动的发生率较低,与地磁活动的相关性尚不十分明确.

关键词：电离层扰动电离层测高仪电离层频高图重力波

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