Geomagnetism and Aeronomy最新文献_第3页

Electromagnetic Monitoring During the Aftershock Period of the 2003 Chuya Earthquake in Gorny Altai: Measurement Technique and Results 2003 年阿尔泰戈尔诺丘雅地震余震期间的电磁监测：测量技术和结果

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600401

A. E. Shalaginov, N. N. Nevedrova

引用次数: 0

Statistical Study of Coronal Mass Ejections of the 23rd and 24th Solar Cycles Based on Their Angular Width 基于角宽度的第 23 和 24 个太阳周期日冕物质抛射统计研究

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793223600753

W. Hannah Blessy, A. Mujiber Rahman, S. S. R. Inbanathan, Pa. Gokhula Prasad

{"title":"Statistical Study of Coronal Mass Ejections of the 23rd and 24th Solar Cycles Based on Their Angular Width","authors":"W. Hannah Blessy, A. Mujiber Rahman, S. S. R. Inbanathan, Pa. Gokhula Prasad","doi":"10.1134/S0016793223600753","DOIUrl":"10.1134/S0016793223600753","url":null,"abstract":"This study is based on the angular width of CMEs from the 23rd and 24th solar cycles. We divided the CMEs seen during the 23rd (1996–2007) and 24th (2008–2017) solar cycles into three categories: Narrow (width ≤ 20°), Intermediate (20° < width < 200°), and Wide (width ≥ 200°). It was found that the 24th solar cycle had twice as much as narrow CMEs than what occurred in the 23rd cycle. Similarly, there were about 1.2 times more intermediate CMEs in the 24th cycle than in the 23rd. Wide CMEs followed a similar trend of 1.3 times the number found for the 23rd cycle. Both cycles followed an analogous trend with respect to the number of CMEs based on their angular width. An intriguing find is that the percentage of slow (speed < 500 km/s) CMEs is greater in narrow and intermediate ones in the 23rd and 24th cycles compared to fast CMEs (speed > 500 km/s), whereas it is the opposite with wide CMEs. Wide CMEs are observed to have the highest mean speed among the three groups. Overall, it was found that all three groups of CMEs in the 23rd solar cycle had faster mean, median, maximum, and minimal speeds than those in the 24th cycle.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218421","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

Variation in the Serpentine Emission Carrier Frequency under Quiet Magnetosphere Conditions 静磁层条件下蛇纹石发射载波频率的变化

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600292

N. A. Kurazhkovskaya, B. I. Klain, A. Yu. Kurazhkovskii

{"title":"Variation in the Serpentine Emission Carrier Frequency under Quiet Magnetosphere Conditions","authors":"N. A. Kurazhkovskaya, B. I. Klain, A. Yu. Kurazhkovskii","doi":"10.1134/S0016793224600292","DOIUrl":"10.1134/S0016793224600292","url":null,"abstract":"The article studies variation in the serpentine emission carrier frequency fSE observed in the 0.1–5.0 Hz frequency range under quiet magnetosphere conditions (Kp ~ 0–2). The data of magnetic field recording at the Antarctic Vostok Observatory (corrected geomagnetic coordinates Φ′ = −85.41°, Λ′ = 69.01°) for 1970‒1972 were used in the analysis. Using the dynamic spectra of ULF emission, we analyzed 90 cases of serpentine emission observation, the center carrier frequency of which gradually decreased (several times, sometimes to 0), then increased almost to the initial level in time intervals significantly exceeding the maximum modulation period (1 h). In this case, typical modulation of the emission carrier frequency with periods of 1–60 min persisted. The most likely time of observation of the detected effect was in the hours before midnight. It is shown that a decrease and subsequent increase in fSE were observed versus weak geomagnetic activity and relative stability of the dominant number of solar wind and IMF parameters. Taking into account the discovered synchronous coincidence of the behavior of fSE and dynamics of the AE-index, as well as observation of the effect of a decrease in the carrier frequency near local midnight, it is suggested that serpentine emission is most likely excited near the polar cusp, then penetrates the polar cap region. The behavior of fSE observed over long time intervals is presumably governed by the plasma parameter β and ratio of the proton density to the helium ion density Np/Na, the dynamics of which are similar to the average variation in fSE.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218560","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

Verification of the Empirical Model of Ionization of the Lower Ionosphere during Solar Flares of Different Classes 验证不同等级太阳耀斑期间下电离层电离的经验模型

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600012

I. A. Ryakhovsky, Y. V. Poklad, B. G. Gavrilov

{"title":"Verification of the Empirical Model of Ionization of the Lower Ionosphere during Solar Flares of Different Classes","authors":"I. A. Ryakhovsky, Y. V. Poklad, B. G. Gavrilov","doi":"10.1134/S0016793224600012","DOIUrl":"10.1134/S0016793224600012","url":null,"abstract":"The results of measuring VLF signal parameters propagating in the Earth-D-region of the ionosphere waveguide to assess changes in the state of the lower ionosphere as a result of the impact of X-ray radiation of solar flares make it possible to obtain qualitative data on the nature and magnitude of the impact. Obtaining accurate data on the relationship between changes in electron concentration and flare parameters and reliable prediction of the conditions of LF radio signal propagation during strong geophysical disturbances is complicated by the lack of complete information on the frequency spectrum of X-ray radiation for a particular flare and data on the ionization rate of the ionosphere for flares of different classes. The technique of determining the X-ray spectrum in a wide range of wavelengths and calculating the ionization coefficients of the lower ionosphere as a function of the ionizing radiation parameters of flares, presented by Ryakhovsky et al. (2023), makes it possible to improve the accuracy in estimating variations in the parameters of the lower ionosphere. The present paper is devoted to verifying the performance of the developed empirical model of lower ionization of the lower ionosphere at the solar flare front and comparing the results with experimental data on the variation of VLF radio parameters.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218565","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

‘Polar’ Substorms and the Harang Discontinuity 极地 "亚暴和哈朗不连续面

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600310

N. G. Kleimenova, L. I. Gromova, S. V. Gromov, L. M. Malysheva, I. V. Despirak

{"title":"‘Polar’ Substorms and the Harang Discontinuity","authors":"N. G. Kleimenova, L. I. Gromova, S. V. Gromov, L. M. Malysheva, I. V. Despirak","doi":"10.1134/S0016793224600310","DOIUrl":"10.1134/S0016793224600310","url":null,"abstract":"We analyzed 214 events of ‘polar’ substorms on the Scandinavian meridian IMAGE, i.e., substorms recorded by magnetometers located at geomagnetic latitudes above ~70° MLAT at 1900−0200 MLT during a magnetically quiet time in the absence of negative magnetic bays at lower latitudes. The Harang discontinuity, which separates the westward and eastward electrojets by latitude, is a typical structure for the indicated MLT sector of the high-latitude ionosphere. The global distribution of ionospheric electrojets and the location of the Harang discontinuity during development of ‘polar’ substorms were studied using the maps compiled from the results of spherical harmonic analysis of magnetic measurements on 66 simultaneous ionospheric communications satellites of the AMPERE project. Based on analysis of these maps, it is shown that the instantaneous location of the equatorial boundary of the ionospheric current of a ‘polar’ substorm determines the instantaneous location of the polar boundary of the Harang discontinuity, and the polar boundary of the eastward electrojet determines its equatorial boundary. It has been established that the appearance of 90% of ‘polar’ substorms is observed simultaneously with increasing planetary substorm activity according to the AL-index and development of a magnetospheric substorm in the postmidnight sector. At the same time, the development of evening ‘polar’ substorms is associated with the formation of near-midnight magnetic vortices at geomagnetic latitudes of ~70° MLAT (near the “nose” of the Harang discontinuity), indicating a sharp local enhancement of the field-aligned currents. This leads to the formation of a new substorm in the evening sector of near-polar latitudes, called a ‘polar’ substorm with typical features of the onset of a substorm (Pi2 geomagnetic pulsation bursts, sudden onset of the substorm close to the equatorial boundary of the contracted oval (the development of a “substorm current wedge”, etc.)","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218418","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

Kinematics of Flare Ribbons during Eruption of Solar Prominences 日珥爆发过程中耀斑带的运动学特征

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600279

B. P. Filippov

引用次数: 0

Seasonal Features of the NmF2 Variability for Different Longitudes of the Middle Latitudes during Enhanced Geomagnetic Activity 地磁活动增强期间中纬度不同经度的 NmF2 变率的季节特征

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600334

V. H. Depuev, M. G. Deminov, G. F. Deminova, A. H. Depueva

{"title":"Seasonal Features of the NmF2 Variability for Different Longitudes of the Middle Latitudes during Enhanced Geomagnetic Activity","authors":"V. H. Depuev, M. G. Deminov, G. F. Deminova, A. H. Depueva","doi":"10.1134/S0016793224600334","DOIUrl":"10.1134/S0016793224600334","url":null,"abstract":"Based on the data of 17 mid-latitude ionospheric stations for 1958–1988, the study analyzes seasonal features of the F2 layer peak concentration (NmF2) at different longitudes with enhanced (48 > ap(τ) > 27) geomagnetic activity, where ap(τ) is the weighted average (with a characteristic time of 14 h) ap-index of this activity. As the characteristics of the NmF2 variability, the standard deviation σ of NmF2 fluctuations relative to quiet level and the average shift of these fluctuations xave during daytime (1100–1300 LT) and nighttime (2300–0100 LT) were used. It was found that at all analyzed stations, the dispersion σ2 for enhanced geomagnetic activity is greater than for quiet conditions, and, other things being equal, it is maximum in winter at night. For enhanced geomagnetic activity in all seasons, the difference in xave values between the analyzed stations is quite large. One of the reasons for this difference is associated with the dependence of xave on geomagnetic latitudes. To select these latitudes, approximations of the geomagnetic field with tilted dipole (TD), eccentric dipole (ED), or with corrected geomagnetic (CGM) coordinates were used. It was found that the xave dependence on the ED latitude is more accurate in comparison to the xave dependence on the TD latitude or CGM latitude during all seasons at night, and during equinoxes and winter, in the daytime. In summer, in the daytime hours, the xave dependences on ED latitude and CGM latitude are comparable in accuracy, and they are more accurate compared to the xave dependence on TD latitude. Consequently, ED latitudes are optimal for taking into account the effects of storms in the F2 layer peak concentration at mid-latitudes during all seasons. This conclusion has apparently been made for the first time.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218563","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

Aerosol Layer of the Lower Thermosphere: II. Observation during a Full Moon 热大气层下部的气溶胶层：II.满月期间的观测

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600346

A. N. Belyaev, S. Sh. Nikolaishvili, A. N. Omel’chenko, A. Yu. Repin, M. A. Poluarshinov, Yu. V. Smirnov, A. V. Strakhov, A. G. Batishchev, V. I. Stasevich, Yu. V. Platov

引用次数: 0

Some Features of Interacting Solar Wind Disturbances 相互作用的太阳风扰动的一些特征

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600280

N. S. Shlyk, A. V. Belov, M. A. Abunina, S. M. Belov, A. A. Abunin, V. A. Oleneva, V. G. Yanke

引用次数: 0

Wave Activity of Gravity Waves in the Mesosphere and Lower Thermosphere during a Meteorological Storm 气象风暴期间中间层和下热层重力波的波活动性

IF 0.7 4区地球科学

Geomagnetism and Aeronomy Pub Date : 2024-08-13 DOI: 10.1134/S0016793224600358

O. P. Borchevkina, F. S. Bessarab, A. V. Timchenko, I. V. Karpov

{"title":"Wave Activity of Gravity Waves in the Mesosphere and Lower Thermosphere during a Meteorological Storm","authors":"O. P. Borchevkina, F. S. Bessarab, A. V. Timchenko, I. V. Karpov","doi":"10.1134/S0016793224600358","DOIUrl":"10.1134/S0016793224600358","url":null,"abstract":"The effect of a meteorological storm in October 2018 in the Baltic Sea on the state of the mesosphere and lower thermosphere is investigated. The wave activity of internal gravity waves from TIMED/SABER satellite data is analyzed, and the effects of the meteorological storm at heights of 80–100 km are determined. A method based on mode decomposition from SABER data is adapted to calculate the gravity wave potential energy density (GWPED) and to isolate the temperature perturbations caused by their propagation at lower thermospheric heights. Wavelet analysis of the temperature perturbations revealed two ranges of vertical wavelengths, 5–8 km and 14–18 km. In the area of a meteorological storm, the amplitude of internal gravity waves with vertical wavelengths of 5–8 km increases, and the area of their maximum expands and shifts upward to heights of ~90 km, while on meteorologically quiet days these waves are observed at heights of 65–70 km and with smaller amplitudes. Above the area of a meteorological storm at heights of 90–100 km, the values of the gravity wave potential energy density increase significantly compared to quiet days before and after the storm, and the spatial extent of the perturbation area increases.","PeriodicalId":55597,"journal":{"name":"Geomagnetism and Aeronomy","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142218567","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