Geomagnetism and Aeronomy最新文献_第7页

Signal-Processing Investigations on the Precursors of Strong Earthquakes Using GPS-TEC, ULF, and VLF Data 基于GPS-TEC、ULF和VLF数据的强震前兆信号处理研究

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-02-10 DOI: 10.1134/S001679322460070X

Swati, Manish Awasthi, Raj Pal Singh, Nitin Dubey, Devbrat Pundhir

{"title":"Signal-Processing Investigations on the Precursors of Strong Earthquakes Using GPS-TEC, ULF, and VLF Data","authors":"Swati, Manish Awasthi, Raj Pal Singh, Nitin Dubey, Devbrat Pundhir","doi":"10.1134/S001679322460070X","DOIUrl":"10.1134/S001679322460070X","url":null,"abstract":"The seismo-electromagnetic studies have been in progress since 1998 at Agra station. In the present paper, ionospheric GPS-TEC, ground-based ULF/VLF measurements were investigated in light of four strong earthquakes (M ≥ 6.8) that occurred around the Indian subcontinent in different periods. These three datasets are processed by using advanced signal-processing techniques in time and frequency domains. To analyze these datasets, a period of 16 days (including the day of the earthquake) was considered. For each day, only one minute of data was taken into account, with the time of the earthquake being the midpoint of that minute. The precursors are obtained in all the datasets considered before the occurrence of earthquakes. In TEC, ULF, and VLF data, significant changes are observed 2 to 15, 2 to 7, and 5 to 13 days before earthquakes, respectively. Significant results are obtained in time and frequency domains and the variations of solar and magnetic storm activities have also been examined thoroughly to check the validity of these variations. Further, these variations are interpreted in terms of lithosphere-atmosphere-ionosphere coupling mechanisms available in the literature.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"64 1 supplement","pages":"S59 - S71"},"PeriodicalIF":0.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Geomagnetic Storms Occurrences and the Variation in the Geomagnetic Storm Indices and Solar Wind Parameters during the Ascending Phase of Solar Cycle 24 第24太阳周期上升阶段地磁暴的发生及地磁暴指数和太阳风参数的变化

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-02-10 DOI: 10.1134/S0016793224600930

B. W. Joshua, J. O. Adeniyi, S. J. Adebiyi

{"title":"Geomagnetic Storms Occurrences and the Variation in the Geomagnetic Storm Indices and Solar Wind Parameters during the Ascending Phase of Solar Cycle 24","authors":"B. W. Joshua, J. O. Adeniyi, S. J. Adebiyi","doi":"10.1134/S0016793224600930","DOIUrl":"10.1134/S0016793224600930","url":null,"abstract":"The occurrence of geomagnetic storms and the variation in the geomagnetic storm indices during the ascending phase of solar cycle 24 has been examined. The parameters considered for this study includes; IMF Bz (nT), solar wind speed (({{{v}}_{x}}), in km/s), Dst index (nT), Aurora Electroject (AE, AU and AL indices in nT), and sunspot number. The datasets span from 2010 to 2012. Results of the study reveals that; the frequency of occurrence of geomagnetic storms increases with the increase in solar activity. Six (6) geomagnetic storms were recorded in 2010 (with sunspot number, Rz = 16.5), 13 storms in 2012 (with sunspot number Rz = 55.7), and 17 storms occurred in 2012 (with sunspot number, Rz = 57.5) giving a total of 36 geomagnetic storm events for the entire period. The performed study demonstrates that an increase in the speed and density of the solar wind coincided with the decrease in the Dst index in 58% cases (in 21 out of 36 geomagnetic storms). However, in some cases, there was a sharp simultaneous increase in both the speed and density of the solar wind that fell on the recovery phase of the storm. This also in most cases coincided with the sharp north-south fluctuations in the IMF Bz. These variations cannot be unconnected with the nature of the drivers of such geomagnetic storms. It is evident that the behavior of the solar wind speed during geomagnetic storm events can provide meaningful insight on the underlying mechanisms and processes that drive the geomagnetic storm.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"64 1 supplement","pages":"S72 - S84"},"PeriodicalIF":0.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pc5 Pulsation Effects during the St. Patrick’s Day Geomagnetic Storm Observed from Chile 智利观测到的圣帕特里克节地磁风暴期间的Pc5脉动效应

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-02-10 DOI: 10.1134/S0016793224600462

J. A. Lazzús, M. N. Castillo, J. Lorca-Castillo, C. Olivares-Salazar, A. Rivera-Zepeda, I. Salfate

{"title":"Pc5 Pulsation Effects during the St. Patrick’s Day Geomagnetic Storm Observed from Chile","authors":"J. A. Lazzús, M. N. Castillo, J. Lorca-Castillo, C. Olivares-Salazar, A. Rivera-Zepeda, I. Salfate","doi":"10.1134/S0016793224600462","DOIUrl":"10.1134/S0016793224600462","url":null,"abstract":"This study investigates Pc5 pulsations during the St. Patrick’s Day geomagnetic storm of March 17, 2015, using ground-based magnetic data from the SER station in Chile (29.827° S, 71.261° W), satellite observations, and geomagnetic indices. Pc5 pulsations, with frequencies of 1.67–6.67 mHz, are influenced by various factors, including the Kelvin–Helmholtz instability, field line resonance effects, and solar wind dynamics. During this storm ignificant variations in solar wind parameters were observed, with positive correlations between Pc5 pulsations and parameters like temperature, density, speed, and pressure, especially during the main and recovery phases Pc5 pulsations exhibited large amplitudes during the storm, potentially driven by magnetospheric MHD waveguide/cavity mode and induced by the substantial compression of the geomagnetic field from the solar wind. Our results show the appearance of Pc5 pulsations at low latitudes and strong correlations between solar wind parameters and Pc5 signals during all storm phases, with maximum correlation coefficients of 0.98.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"64 1 supplement","pages":"S52 - S58"},"PeriodicalIF":0.7,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143612221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On Possible Additional Sources of Solar Protons in the Events of September 4–10, 2017 2017年9月4-10日事件中太阳质子可能的额外来源

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700221

I. Yu. Grigor’eva, V. A. Ozheredov, A. B. Struminsky

{"title":"On Possible Additional Sources of Solar Protons in the Events of September 4–10, 2017","authors":"I. Yu. Grigor’eva, V. A. Ozheredov, A. B. Struminsky","doi":"10.1134/S0016793224700221","DOIUrl":"10.1134/S0016793224700221","url":null,"abstract":"The article considers the period from September 4 to September 10, 2017, inclusive, during which the last proton events of solar cycle 24 occurred. In order to detect possible additional proton sources and verify the sources already listed in various catalogs, we apply an empirical method for predicting proton events to all solar flares detected during this period. It is based on the threshold criteria of the parent flares. In addition, we apply an algorithm for automatic search of proton flares obtained by machine learning. Two variants of the automatic search algorithm are used: the first one (method 319) does not take into account the duration of the radio emission, while the second one (method 189) imposes a condition on its duration (>2 min). The empirical method shows that, except for the source flares found by the time of the first arrival of solar protons on Earth, other flares of this period do not fulfill all the criteria of “protonicity.” An additional test of the automatic method is the detection of proton flares that we selected by the protonicity criteria but that did not make it to the training sample. Method 319 considers proton flares X9.3 on September 6, 2017, M1.4 and X1.3 on September 7, 2017, and C8.3 on September 8, 2017, as proton flares. Method 189 does not consider the flares of September 7 and 8, 2017, as credible proton sources, which is consistent with expert empirical estimates of the protonicity criteria.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"64 7","pages":"1148 - 1156"},"PeriodicalIF":0.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994815","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Current Solar Cycle 25 on the Eve of the Maximum Phase 当前太阳活动周期25在极大期前夕

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700257

V. N. Ishkov

引用次数: 0

Long-Range Correlations in 2D Structures of the Magnetic Field Dissipation in the Photosphere of Solar Active Regions 太阳活动区光球磁场耗散二维结构的长程相关

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700014

V. I. Abramenko, R. A. Suleymanova, A. S. Kutsenko

{"title":"Long-Range Correlations in 2D Structures of the Magnetic Field Dissipation in the Photosphere of Solar Active Regions","authors":"V. I. Abramenko, R. A. Suleymanova, A. S. Kutsenko","doi":"10.1134/S0016793224700014","DOIUrl":"10.1134/S0016793224700014","url":null,"abstract":"Vector-magnetograms acquired by the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) were utilized to explore the spatial correlation functions of the dissipative structures, such as the vertical magnetic field dissipation, Ediss, the squared density of the vertical electric current, (J_{z}^{2}), the current helicity density, Hc. Six mature active regions (ARs) were explored, three of them belong to the magneto-morphological class (MMC) A1—regular ARs that follow the empirical rules of the Babcock-Leighton dynamo theory, and the rest three ARs belong to the MMC B3 class, irregular multipolar ARs. We found that, on the contrary to the vertical magnetic field structures (see (Abramenko, Suleymanova 2024)), all considered here dissipative structures reveal a range of the power law in the correlation function. Parameters of the power law vary significantly for different types of the considered structures and for different ARs of different classes. The most pronounced difference in the power law parameters between the AR’s classes was found for both (J_{z}^{2}) and Hc: the B3-class ARs demonstrate a capability for longer correlations and shallower power law slope than the A1-class ARs do. As soon as the power law correlation function is thought to indicate the self-organized criticality (SOC) state, we might conclude that in the photosphere, the SOC is rather observable in the magnetic dissipative structures, than in the magnetic field itself; a signature of SOC seems to be stronger manifested in the complex irregular B3-class ARs with high flaring activity. The proposed approach can facilitate to find a connection between the photosphere and upper layers in setting up the critical state, which is necessary for eruptions of all scales.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"64 7","pages":"995 - 1003"},"PeriodicalIF":0.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Double Plasma Resonance in Electron–Positron Plasma at the Pulsar Magnetosphere 脉冲星磁层中电子-正电子等离子体的双等离子体共振

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700063

V. E. Shaposhnikov, T. V. Simonova

引用次数: 0

Constraints on the Parameters of Solar Superflares Based on Cosmogenic Radiocarbon Data in the Lunar Regolith 基于月球风化层放射性碳数据的太阳超级耀斑参数约束

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700075

G. I. Vasilyev, A. N. Konstantinov, I. V. Kudryavtsev, E. S. Melikhova, V. M. Ostryakov, A. K. Pavlov

{"title":"Constraints on the Parameters of Solar Superflares Based on Cosmogenic Radiocarbon Data in the Lunar Regolith","authors":"G. I. Vasilyev, A. N. Konstantinov, I. V. Kudryavtsev, E. S. Melikhova, V. M. Ostryakov, A. K. Pavlov","doi":"10.1134/S0016793224700075","DOIUrl":"10.1134/S0016793224700075","url":null,"abstract":"Samples with a short-term (less than a year) increase in the content of the radioactive isotope 14C were recently discovered in tree rings, in four cases accompanied by concentration growth of 10Be and 36Cl in other natural archives. Most publications suggest that this increase is due to a sharp increase in the flux of solar cosmic rays (SCR) at the boundary of the Earth’s atmosphere caused by solar superflares. Other reasons may be connected with the flux rise of the galactic cosmic rays (GCR) as the Solar System passes through a dense interstellar cloud, or a galactic gamma-ray burst. To reconcile the amount of 14C with cosmogenic isotopes 10Be and 36Cl formed in the atmosphere, it is necessary to assume that the proton spectra in such superflares should be harder than most modern experimentally recorded ones. Measurements of the 14C content in lunar regolith cores returned by the Apollo 15 expedition showed a significant drop in radiocarbon concentration to a depth of 5 g/cm2, followed by an increase to maximum values at about 50 g/cm2 then a decrease. At shallow depths, the contribution from low-energy SCRs predominates, and at large depths, the contribution from high-energy GCRs prevails. Analysis of the depth profile of the 14Cconcentration makes it possible to establish SCR fluxes and spectra over several radiocarbon half-lives (10 000–20 000 years) and highlight the possible contribution of hypothetical superflares. Our analysis shows that the hypothesis of solar superflares worsens the agreement with the observed depth variations of 14C in the lunar regolith.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":"64 7","pages":"1049 - 1053"},"PeriodicalIF":0.7,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Solar Flares in White Light and Heating of the Solar Photosphere by Alfvén Waves 白光下的太阳耀斑和alfvsamn波对太阳光球的加热

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700178

Yu. T. Tsap, Yu. G. Kopylova

引用次数: 0

Period of the “Envelope” of the Maximum of Reliable Cycles of a Series of Wolf Numbers and the Image of Increased/Decreased Solar Activity Epochs 一系列狼数可靠周期最大值的“包络线”周期和太阳活动增减期图像

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2025-01-16 DOI: 10.1134/S0016793224700294

I. G. Shibaev, A. I. Shibaev

引用次数: 0