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Joint observations of the large-scale ULF wave activity from space to ground associated with the solar wind dynamic pressure enhancement

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Science China(Technological Sciences) 2024年第7期67卷 2215-2229页

作者： SUN XiaoYing HU YunPeng zhima zeren DUAN SuPing LV FangXian SHEN XuHui National Institute of Natural Hazards Ministry of Emergency ManagementBeijing 100085China School of Space and Environment Beihang UniversityBeijing 102206China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China

This study reports the rare ultralow-frequency(ULF) wave activity associated with the solar wind dynamic pressure enhancement that was successively observed by the GOES-17(Geostationary Operational Environmental Satellite) in the magnetosphere, the CSES(China Seismo-Electromagnetic Satellite) in the ionosphere, and the THEMIS ground-based observatories(GBO) GAKO and EAGL in the Earth's polar region during the main phase of an intense storm on 4 November 2021. Along with the enhanced-pressure solar wind moving tailward, the geomagnetic field structure experienced a large-scale change. From dawn/dusk sides to midnight, the GAKO, EAGL, and GOES-17 sequentially observed the ULF waves in a frequency range of0.04–0.36 Hz at L shells of ~5.07, 6.29, and 5.67, respectively. CSES also observed the ULF wave event with the same frequency ranges at wide L-shells of 2.52–6.22 in the nightside ionosphere. The analysis results show that the ULF waves at ionospheric altitude were mixed toroidal-poloidal mode waves. Comparing the ULF waves observed in different regions, we infer that the nightside ULF waves were directly or indirectly excited by the solar wind dynamic pressure increase: in the area of L-shells~2.52–6.29, the magnetic field line resonances(FLRs) driven by the solar wind dynamic pressure increase is an essential excitation source;on the other hand, around L~3.29, the ULF waves can also be excited by the outward expansion of the plasmapause owing to the decrease of the magnetospheric convection, and in the region of L-shells ~5.19–6.29, the ULF waves are also likely excited by the ion cyclotron instabilities driven by the solar wind dynamic pressure increase.

关键词： ultralow-frequency(ULF)wave solar wind dynamic pressure(P_(sw)) magnetic field line resonance(FLR) ion cyclotron instability

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Preliminary geological interpretation of long-wavelength magnetic anomalies over China and surrounding regions

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Earth and Planetary Physics 2024年第3期8卷 445-458页

作者： Jie Wang YanYan Yang zhima zeren Jian Wang Xin Wang YuXin Luo XuHui Shen National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Key Laboratory of Compound and Chained Natural Hazards Dynamics Ministry of Emergency Management of ChinaBeijing 100085China School of Emergency Management Science and Engineering University of Chinese Academy of SciencesBeijing 100049China National Space Science Center Chinese Academy of SciencesBeijing 100190China

Long-wavelength(>500 km)magnetic anomalies originating in the lithosphere were first found in satellite magnetic *** to the striking magnetic anomalies around the world,the long-wavelength magnetic anomalies in China and surrounding regions are relatively *** research on each of these anomalies has been quite inadequate;their geological origins remain unclear,in particular their connection to tectonic activity in the Chinese and surrounding *** focus on six magnetic high anomalies over the(1)Tarim Basin,(2)Sichuan Basin(3)Great Xing’an Range,(4)Barmer Basin,(5)Central Myanmar Basin,and(6)Sunda and Banda Arcs,and a striking magnetic low anomaly along the southern part of the Himalayan-Tibetan *** have analyzed their geological origins by reviewing related research and by detailed comparison with geological *** tectonic backgrounds for these anomalies belong to two cases:either ancient basin basement,or subduction-collision ***,the geological origins of large-scale regional magnetic anomalies are always subject to dispute,mainly because of limited surface exposure of sources,later tectonic destruction,and superposition of multi-phase events.

关键词： long-wavelength magnetic anomaly lithospheric magnetic anomaly lithospheric magnetic field model satellite magnetic survey CSES

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基于Swarm卫星磁测数据的全球多场源地磁场建模

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地球物理学报 2024年第5期67卷 1881-1890页

作者：杨艳艳泽仁志玛申旭辉王婕黄建平王桥鲁恒新应急管理部国家自然灾害防治研究院北京100085 中国科学院国家空间科学中心北京100190

全球多场源地磁场模型因其可同时描述场源多、使用方便等优点在很多行业中得到了应用.本文基于高精度磁测卫星Swarm A自发射以来的九年标量和矢量观测数据,利用球谐分析方法,同时实现主磁场及其变化、岩石圈磁场和磁层外源场模型系数的... 详细信息

全球多场源地磁场模型因其可同时描述场源多、使用方便等优点在很多行业中得到了应用.本文基于高精度磁测卫星Swarm A自发射以来的九年标量和矢量观测数据,利用球谐分析方法,同时实现主磁场及其变化、岩石圈磁场和磁层外源场模型系数的反演.其中内源场球谐截止阶数70阶,对应空间分辨率为571 km;主磁场变化求解至13阶,采用6阶B样条函数描述,可实现主磁场长期变化、长期加速度等的计算;外源场球谐截止阶数2阶.统计结果表明最终模型拟合rms为3.29 nT.为了对模型结果开展评估,先后利用综合场模型CM6和CHAOS-7对功率谱以及各场源全球分布开展了对比,结果表明该模型与CM6和CHAOS-7模型结果在趋势和量值上均十分接近,其中主磁场、岩石圈磁场和磁层外源场与CHAOS-7模型典型残差分别在5 nT、1 nT和2 nT以内.此外,基于Swarm A卫星模型,我们还分析了2014和2023年的全球主磁场变化特征,对全球岩石圈磁异常和外源场分布规律进行了展示和总结.通过本项工作可以实现多场源模型系数的同步解算,为相关行业应用提供技术支撑.

关键词：卫星磁测地磁场模型主磁场岩石圈磁场外源场

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A lithosphere-atmosphere-ionosphere coupling model for ELF electromagnetic waves radiated from seismic sources and its possibility observed by the CSES

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Science China(Technological Sciences) 2021年第11期64卷 2551-2559页

作者： ZHAO ShuFan SHEN XuHui LIAO Li zeren zhima National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Institute of Geophysics China Earthquake AdministrationBeijing 100081China

Over the last century, abnormal electromagnetic(EM) emissions associated with earthquake(EQ) activities have been widely reported and recorded by ground-based and satellite observations. The mechanism of extremely low-frequency(ELF) EM waves radiated from earthquakes has been gradually established. However, whether EM waves radiated from earthquakes can be detected by low Earth orbit(LEO) satellites remains controversial. In this paper, to address these concerns, a lithosphereatmosphere-ionosphere model of ELF wave propagation is constructed. The features of the simulated EM field at LEO satellite altitudes radiated from earthquakes have been studied. The simulated EM field at the altitude of the China Seismo-Electromagnetic Satellite(CSES) is compared with the sensitivity of electromagnetic(EM) sensors onboard the CSES. The results illustrate that an earthquake with a magnitude over 6.0 can be detected by the EM sensors of the CSES. However, this depends on the focal depth, seismogenic environment and ionospheric parameters.

关键词： earthquakes CSES satellite sensitivity trans-lithosphere-atmosphere-ionosphere ELF wave propagation model

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改进YOLOv5的闪电哨声波轻量化自动检测模型

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空间科学学报 2024年第3期44卷 458-473页

作者：路超泽仁志玛杨德贺孙晓英吕访贤冉子霖申旭辉应急管理部国家自然灾害防治研究院北京100085 中国科学院大学应急管理科学与工程学院北京100049 中国科学院国家空间科学中心北京100190

提出一种改进YOLOv5(You-Only-Look-Once version 5)检测模型YOLOv5-Upgraded.为了更快定位真实边框,该模型将损失函数CIoU (Complete IoU)替换为SIoU(Scylla IoU);同时为了避免网络训练过程中梯度消失、梯度爆炸以及神经元坏死等现象,... 详细信息

提出一种改进YOLOv5(You-Only-Look-Once version 5)检测模型YOLOv5-Upgraded.为了更快定位真实边框,该模型将损失函数CIoU (Complete IoU)替换为SIoU(Scylla IoU);同时为了避免网络训练过程中梯度消失、梯度爆炸以及神经元坏死等现象,将激活函数SiLU(Sigmoid-weighted Linear Unit)替换为具有更好梯度流的Mish;在主干网络中插入注意力(Coordinate Attention, CA)机制,帮助模型更精准地识别闪电哨声波,大大降低了漏检率.基于张衡一号感应磁力仪(Search Coil Magnetometer, SCM)数据,以2.4 s时间窗口截取数据,经带通滤波、短时傅里叶变换得到1126张时频图数据集,再经图像增强操作扩充至7882张,其中7091张作为训练集, 791张作为测试集.实验结果表明,基于改进YOLOv5的模型平均精度均值为99.09%,召回率为96.20%,与YOLOv5s相比,分别提升了2.75%和5.07%,与基于时频图的YOLOv3模型相比,平均精度均值和召回率则分别提高了5.89%和9.62%.基于智能语音的LSTM (Long Short Term Memory Networks)闪电哨声波识别模型大小为82.89 MB, YOLOv5-Upgraded仅为13.78 MB,约节省83.38%的内存资源.研究表明改进后的轻量化模型大大降低了闪电哨声波的漏检现象,在测试集中取得了较好结果,并且其轻量化特征易于部署到卫星设备,极大地提高了星载识别的可能性.

关键词：张衡一号卫星闪电哨声波 YOLOv5 轻量化自动检测

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Detecting seismic electromagnetic ELF anomalies associated with the 2010 Yushu earthquake in China by DEMETER observations and ELF Lithosphere-Atmosphere-Ionosphere coupling propagating model

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Science China(Technological Sciences) 2023年第4期66卷 1192-1202页

作者： LIAO Li ZHAO ShuFan SHEN XuHui zeren zhima PENG HuaiYun LU HengXin Institute of Geophysics China Earthquake AdministrationBeijing 100081China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China China Research Institute of Radiowave Propagation Qingdao 266107China

Over the last century,abnormal electromagnetic(EM)emissions associated with earthquake(EQ)activities have been widely reported and recorded by ground-based and satellite ***,the frequency at which abnormal EM emissions have been detected *** addition,whether low Earth orbit(LEO)satellites can detect EM anomalies from EQs remains *** this paper,we take the Yushu earthquake as an example to address these concerns by DEMETER satellite observations and a newly constructed lithosphere-atmosphere-ionosphere model of extremely low frequency(ELF)wave *** results illustrate that the frequency of ELF EM anomalies of the Yushu earthquake is mainly at 200–400 *** observations and simulations illustrate that the power-frequency curve of the ELF EM wave from an underground source has a peak power frequency at 200–400 Hz,which is significantly different from the ELF EM wave radiated from the ground source.

关键词： seismic electromagnetic anomalies extremely low frequency(ELF)wave low Earth orbit(LEO)satellites lithosphereatmosphere-ionospheremodel

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Ionospheric TEC and plasma anomalies possibly associated with the 14 July 2019 M_(w) 7.2 Indonesia Laiwui earthquake,from analysis of GPS and CSES data

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Earth and Planetary Physics 2022年第4期6卷 313-328页

作者： YuanZheng Wen Dan Tao GuangXue Wang JiaYi Zong JinBin Cao Roberto Battiston zhima zeren XuHui Shen Key Laboratory of Earth Exploration and Information Techniques of Ministry of Education Chengdu University of TechnologyChengdu 610059China School of Geophysics Chengdu University of TechnologyChengdu 610059China School of Space and Environment Beihang UniversityBeijing 100191China Dipartimento di Fisica Universitàdi TrentoTrento 38123Italy Trento Institute for Fundamental Physics and Applications(TIFPA) National Institute for Nuclear Physics(INFN)Trento 34136Italy National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China

This study presents signatures of seismo-ionospheric perturbations possibly related to the 14 July 2019 M_(w)7.2 Laiwui earthquake,detected by a cross-validation analysis of total electron content(TEC)data of the global ionospheric map(GIM)from GPS and plasma parameter data recorded by the China Seismo-Electromagnetic Satellite(CSES).After separating pre-seismic ionospheric phenomena from the ionospheric disturbances due to the magnetospheric and solar activities,we have identified three positive temporal anomalies,around the epicenter,at 1 day,3 days and 8 days before the earthquake(14 July 2019),along with a negative anomaly 6 days after the *** results agree well with the TEC spatial variations in latitude-longitude-time(LLT)*** confirm these anomalies further,we employed the moving mean method(MMM)to analyze ionospheric plasma parameters(electron,O^(+) and He^(+) densities)recorded by the Langmuir probe(LAP)and Plasma Analyzer Package(PAP)onboard the *** analysis detected on,on Day Two,Day Four,and Day Seven before the earthquake,remarkable enhancements along the orbits around when in proximity to the *** make the investigations still more convincing,we compared the orbits on which anomalous readings were recorded to their corresponding four nearest revisiting orbits;the comparison did indeed indicate the existence of plasma parameter anomalies that appear to be associated with the Laiwui *** these results ilustrate that the unusual ionospheric perturbations detected through GPS and CSES data are possibly associated with the M_(w)7.2 Laiwui earthquake,which suggests that at least some earthquakes may be predicted by alertness to pre-seismic ionospheric anomalies over regions known to be at seismic *** case study also contributes additional information of value to our understanding of lithosphere-atmosphere-ionosphere coupling.

关键词： seismo-ionospheric perturbations CSES sallite ionosphere earthquake

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Disturbance identification of electric field data observed by the CSES-01 satellite before earthquakes

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Science China Earth Sciences 2023年第8期66卷 1814-1824页

作者： Jianping HUANG Fuzhi ZHANG Zhong LI Xuhui SHEN Baiyi YANG Wenjing LI zhima zeren Hengxin LU Qiao TAN National Institute of Natural Hazards Ministry of Emergency ManagementBeijing 100085China Institute of Intelligent Emergency Information Processing Institute of Disaster PreventionLangfang 065201China

Numerous studies have confirmed that electromagnetic disturbances before earthquakes can be observed by *** this study,we use the C-value method that includes the acoustic whistle signature;pre-seismic ionospheric electromagnetic disturbance signals were acquired based on the CSES-01 satellite electric field data,and the maximum value of C in the earthquake preparation zones increased continuously from 2.0 three days before the earthquake and reached a maximum weight of 3.0 on the day of the earthquake,after the earthquake,it gradually decreased and recovered to about 2.0;its the C values fluctuated between-2 and 3,it is different from the C values range-2–12 of the previous seismic case study using the DEMETER satellite,which may be related to the orbital altitude and revisit period of the ***,the C values were normalized,and the time series analysis of the obtained θ values were done,and the results showed that:In the pregnant zone,the background variation of the disturbance amplitude θ is within 2σ,and the maximum disturbance amplitude of θ starts to increase gradually from the seventh period(one period of 5 days,i.e.,35–39 days before the earthquake),it reached 2σ by the fourth preseismic cycle(20–24 days before the earthquake),and then dropped sharply to about 1.5σ in the third pre-seismic cycle(15–19days before the earthquake),after two cycles of increase,the θ over the epicenter reached a maximum of 2.1σ at the time of the earthquake(combining the time of the earthquake and the satellite flight characteristics,the epicenter period is defined as January25-January 29,2020,and this defines the study time period line),and the θ decreases to within 2 times the standard range after the earthquake;The negative value of the disturbance amplitude θ in the central region of the pregnant seismic zone during the earthquake shows the transient energy release *** comparison,the θ values obtained by normalization based on the C-value method

关键词： The CSES-01 satellite Whistle Electric field C-value method Normalization

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Stability validation on the VLF waveform data of the China-Seismo-Electromagnetic Satellite

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Science China(Technological Sciences) 2022年第12期65卷 3069-3078页

作者： YANG DeHe zhima zeren WANG Qiao HUANG JianPing WANG XiuYing ZHANG ZhenXia ZHAO ShuFan GUO Feng CHENG WanLi LU HengXin SHEN XuHui National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Henan Earthquake Agency Zhengzhou 450016China

The China-Seismo-Electromagnetic Satellite(CSES),which was launched in February 2018,carries the search coil magnetometer(SCM)and the electric field detector(EFD)to realize the high-resolution electromagnetic field and wave detection in the upper *** to the complexity and variability of the ionospheric environment,the stability of such a high sampling rate and high-precision electromagnetic field detection systems is always an essential link in data processing and the scientific application of *** work evaluates the stability of the very-low-frequency(VLF)band detection by validating the systemic sampling-time differences between SCM and EFD in the VLF burst-mode *** optimal waveform data preprocessing method is put forward according to the noise levels of the VLF burst-mode observation and the inherent design characteristics of *** VLF waveform data of EFD is rebuilt by filling the data gaps among the sampling sub-periods,making it with a similar sample length to *** by precisely intercepting the maximum and minimum values of the burst-mode waveforms,the variation of the sampling-time difference between EFD and SCM is statistically *** show that during the three years'operation,the sampling-time difference between EFD and SCM predominately keeps below 0.5 s,indicating good stability of EFD and SCM on *** we developed an automatic synchronization tool based on the similarity function and STA/LTA(short time average over long time average)characteristic *** tool can effectively realize the precise synchronization between SCM and EFD in the VLF burst-mode *** work is helpful to upgrade the data quality of CSES and provides technical support for electromagnetic wave propagation studies.

关键词： stability CSES EFD SCM sampling-time difference quasiperiodic waves

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岩石圈长波长磁异常及其地质意义

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地球与行星物理论评（中英文） 2024年第6期55卷 668-680页

作者：王婕杨艳艳纪飞罗钰馨泽仁志玛黄建平申旭辉应急管理部国家自然灾害防治研究院北京100085 中国科学院大学应急管理科学与工程学院北京100049 中国科学院国家空间科学中心北京100190

在低轨卫星几百千米的高度上,大部分近地表观测到的岩石圈磁异常细节衰减殆尽,只留下衰减较慢的长波长磁异常.长波长磁异常可以揭示出岩石圈居里面以上显著的物性差异,对于研究地壳深部的物质组成、结构和演化具有重要意义.为了使读者... 详细信息

在低轨卫星几百千米的高度上,大部分近地表观测到的岩石圈磁异常细节衰减殆尽,只留下衰减较慢的长波长磁异常.长波长磁异常可以揭示出岩石圈居里面以上显著的物性差异,对于研究地壳深部的物质组成、结构和演化具有重要意义.为了使读者能从全球尺度上对长波长磁异常的起源形成具体的认识,本文首先回顾了不同时期的卫星磁异常图及主要的岩石圈磁场模型,然后基于CHAOS-7模型计算结果,对500 km高度除极区外幅值大于4 nT的长波长磁异常进行了识别编号,共计29个磁异常.其中,陆地上磁异常20个,海洋中磁异常9个.通过对已有研究成果的综述及地质资料的对比分析,逐一介绍了磁异常的起源.陆地区域的长波长磁异常大多位于前寒武基底,相关的地质单元有太古代地核、元古代地体、富铁建造等,少数位于造山带背景.海洋区域的长波长磁异常全部都位于洋底高原,普遍与白垩纪时期冈瓦纳大陆裂解相关,具有加厚地壳特征.因此,针对长波长磁异常的持续深入研究对于地壳生长和演化具有重要意义.随着我国卫星磁测的蓬勃发展,相信会有越来越多的国内科研人员关注并研究这类大规模磁异常.

关键词：长波长磁异常卫星磁测岩石圈磁异常前寒武基底洋底高原

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