Solar-Terrestrial Physics最新文献

{"title":"Relation between the area of polar coronal holes and the solar wind speed at a minimum between solar cycles 22 and 23","authors":"Aleksey Borisenko, Sergey Bogachev","doi":"10.12737/stp-93202313","DOIUrl":"https://doi.org/10.12737/stp-93202313","url":null,"abstract":"We have used data from the space telescope SOHO/EIT and the spectrometer VEIS on the Wind spacecraft to compare the solar wind (SW) speed near Earth's orbit with changes in the area of polar coronal holes (CHs) on the Sun during the 1996 solar activity minimum. We have found that in March 1996 the SW speed correlated with the southern CH area by a factor of 0.64. In September and October 1996, a correlation was revealed between the SW speed and the area of the northern CH (the coefficients are 0.64 and 0.85 respectively). We believe that this confirms the assumption that the solar wind from polar CHs can penetrate into the ecliptic plane at solar minimum. The SW speed was 460–500 km/s, which is lower than that from equatorial CHs (600–700 km/s).","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Monitoring of magnetospheric parameters based on cosmic ray effects in August","authors":"Ivan Kovalev, Sergey Olemskoy, Valeriy Sdobnov","doi":"10.12737/stp-93202303","DOIUrl":"https://doi.org/10.12737/stp-93202303","url":null,"abstract":"Using data (uncorrected for the temperature effect) from the global network of neutron monitors (GNNM), along with data from the Yakutsk muon telescope complex and the muon hodoscope URAGAN (Moscow), we have applied a modified spectrographic global survey (SGS) method to the 2018 August event in order to split cosmic ray variations into components of primary, magnetospheric, and atmospheric origin. We obtained time variations in the 4 GV-rigidity primary particle isotropic flux and pitch-angle anisotropy, as well as in the interplanetary magnetic field (IMF) orientation. We also showed variations in the geomagnetic cutoff rigidity (GCR) in Irkutsk.
 Using the obtained data on the changes in the planetary system of GCR within a simple model of a bounded magnetosphere, we have calculated some parameters of magnetospheric current systems, namely, the ring current radius, the magnetopause current radius, and the Dst index.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solar activity cycle 25: the first three years","authors":"Sergey Yazev, Elena Isaeva, Battulga Hos-Erdene","doi":"10.12737/stp-93202301","DOIUrl":"https://doi.org/10.12737/stp-93202301","url":null,"abstract":"We analyze features of current solar activity cycle 25 for the first three years of its development (2020–2022). Compared to cycle 24, the current cycle is shown to exceed the previous one in the number of sunspot groups (1.5 times), the number of flares (1.8 times), and the total flare index (1.5 times). We have found that distributions of sunspot groups during cycles 24 and 25 differ in maximum area. Solar cycle 25, unlike cycle 24, exhibits the most significant increase in the number of sunspot groups with areas up to 30 pmh and in the interval from 570 to 1000 pmh. In contrast to cycle 24, the degree of north-south asymmetry in cycle 25 is significantly reduced. This allows us to predict an increased height of cycle 25, as compared to cycle 24 (by 20–50 %), in accordance with the Gnevyshev—Ol rule, as well as the possible unimodal nature of the cycle.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hysteresis effect between geomagnetic activity indices (Ap, Dst) and interplanetary medium","authors":"Nadezhda Kurazhkovskaya, Alexander Kurazhkovskii","doi":"10.12737/stp-93202308","DOIUrl":"https://doi.org/10.12737/stp-93202308","url":null,"abstract":"We have studied the relationship of geomagnetic activity indices (Ap, Dst) on time intervals, equal to solar cycles (∼11 years), with solar activity indicators and heliospheric parameters. It is shown that the plots of the Ap and Dst indices versus solar activity indicators, as well as versus heliospheric parameters, i.e. solar wind and IMF parameters in the ascending and descending phases of solar activity cycles 21–24 do not coincide, which is indicative of the hysteresis phenomenon. The Ap and Dst indices form hysteresis loops with all parameters we analyze during cycles 21–24. The shape and area of the hysteresis loops, as well as the direction of rotation, clockwise or counterclockwise, depend significantly on indicators of solar activity, heliospheric parameters and change from cycle to cycle. We have found a tendency for the extension and area of the hysteresis loops to decrease from cycle 21 to cycle 24. Analysis of the variability in the shape and size of the hysteresis loops formed by the Ap and Dst indices with solar indicators and heliospheric parameters gives reason to believe that the obtained loops reflect the long-term evolution of the solar wind energy flux, which determines global geomagnetic activity and the magnetospheric ring current intensity in the ascending and descending phases of solar activity cycles 21‒24.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Database of geomagnetically induced currents in the main transmission line “Northern Transit”","authors":"Vasiliy Selivanov, Tatyana Aksenovich, Vladislav Bilin, Vitaliy Kolobov, Yaroslav Saharov","doi":"10.12737/stp-93202311","DOIUrl":"https://doi.org/10.12737/stp-93202311","url":null,"abstract":"Database containing the results of measurements of geomagnetically induced currents (GIC) for the period of 2011 to 2022 in transformer neutrals at three 330 kV substations of the main power transmission lines “Northern Transit” passing through the territory of the Republic of Karelia, Murmansk and Leningrad regions has been created and is publicly available. The GIC value depends on the geoelectric field magnitude in the Earth surface, on the relative position of the substations to which the power transmission lines are connected, and on the resistance of electrical network elements. Important factors are the electrical network branching, which determines paths of induced current spreading, and the network topology at the time of monitoring data acquisition. We describe the structure and principles of functioning of the Russian unique regional monitoring system of geomagnetically induced currents in the electrical network. We demonstrate the features of the data contained in the GIC database, which must be taken into account when processing and analyzing the data. Examples of using the GIC database for energy and geophysical studies are given. The work performed on the organization of continuous monitoring of GIC at substations of the main power transmission line in the Arctic zone has no analogues in the Russian Federation and provides extensive original material that allows us to study geomagnetic disturbances and their impact on electrical networks. The database is available at [http://gic.en51.ru]","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of geomagnetic disturbances on scintillations of GLONASS and GPS signals as observed on the Kola Peninsula","authors":"Vladimir Belahovskiy, Pavel Budnikov, Alexey Kalishin, Sergey Pilgaev, Alexey Roldugin","doi":"10.12737/stp-93202307","DOIUrl":"https://doi.org/10.12737/stp-93202307","url":null,"abstract":"We have compared effects of geomagnetic disturbances during magnetic storms of various types (CME and CIR) and during an isolated substorm on scintillations of GLONASS and GPS signals, using a Septentrio PolaRx5 receiver installed in Apatity (Murmansk Region, Russia). We analyze observational data for 2021. The magnetic storms of November 3–4, 2021 and October 11–12, 2021 are examined in detail. The November 3–4, 2021 magnetic storm was one of the most powerful in recent years. The analysis shows that the scintillation phase index reaches its highest values during nighttime and evening substorms (σϕ≈1.5–1.8), accompanied by a negative bay in the magnetic field. During magnetic storms, positive bays in the magnetic field, associated with an increase in the eastward electrojet, lead, however, to quite comparable values of the phase scintillation index.
 An increase in phase scintillations during nighttime and evening disturbances correlates with an increase in the intensity of ULF waves (Pi3/Pc5 pulsations) and with the appearance of aurora arcs. This confirms the important role of ULF waves in forming the auroral arc and in developing ionospheric irregularities. The predominance of the green line in the spectrum of auroras indicates the contribution of disturbances in the ionospheric E layer to the scintillation increase. Pulsating auroras, associated with ionospheric disturbances in the D layer, do not lead to a noticeable increase in phase scintillations. Analysis of ionospheric critical frequencies according to ionosonde data from the Lovozero Hydrometeorological Station indicates the contribution of the sporadic Es layer of the ionosphere to jumps in phase scintillations.
 The difference between phase scintillation values on GLONASS and GPS satellites during individual disturbances can be as great as 1.5 times, which may be due to different orbits of the satellites. At the same time, the level of GLONASS/GPS scintillations at the L2 frequency is higher than at the L1 frequency. We did not find an increase in the amplitude index of scintillations during the events considered.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Natural electromagnetic oscillations in 4–12 Hz frequency range as measured by SWARM satellites and CARISMA magnetometer network","authors":"Nadezda Yagova, Evgeny Fedorov, Vyacheslav Pilipenko, Nikolay Mazur","doi":"10.12737/stp-93202314","DOIUrl":"https://doi.org/10.12737/stp-93202314","url":null,"abstract":"We examine magnetic field variations at 4–12 Hz frequencies in the upper ionosphere and on Earth. The ground response to the coherent oscillations at two SWARM satellites near and above the high frequency boundary of the nominal Pc1 range is studied. We use CARISMA data to analyze ground pulsations. Ionospheric oscillations are predominantly registered at geomagnetic latitudes above 65°, i. e. from the auroral zone to the polar cusp-cleft region. The oscillations at the same frequencies are recorded at auroral and subauroral ground stations at distances from 1500 to 3000 km from satellite footprint. Ratio RGI of the oscillation amplitude on Earth to that in the ionosphere retrieved from the observed data is compared to the values calculated for a finite radius Alfvén beam incident onto a quasi-real ionosphere. [Fedorov et al., 2018]. Radial distribution of RGI depends on the oscillation frequency and the altitude distribution of ionospheric parameters controlled mostly by season and local time. The most probable values of RGI range from 10–3 to 10–1. The RGI values obtained from the observed data agree with model ones at incident beam radius of about several hundred kilometers.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Partial ponderomotive forces of Alfvén waves in near-Earth plasma","authors":"Anatol Guglielmi, Feliks Feygin","doi":"10.12737/stp-93202304","DOIUrl":"https://doi.org/10.12737/stp-93202304","url":null,"abstract":"In the study of the ponderomotive action of Alfvén waves on near-Earth plasma, the general formula for ponderomotive forces, known in classical electrodynamics of continuous media, was previously used. The formula does not explicitly take into account the multi-ion composition of the plasma. Under the action of the waves, significant changes were found in macroscopic parameters — plasma density and velocity. Plasma in Earth’s magnetosphere contains ions with different charge-to-mass ratios. Besides hydrogen and helium ions, the plasma has an admixture of oxygen ions of ionospheric origin, as well as an admixture of other heavy ions. In this connection, a wide range of problems arise on the ponderomotive separation of ions of various types. To solve these problems, it is proposed to use partial ponderomotive forces and to describe the plasma not by hydrodynamic, but by quasi-hydrodynamic equations. In this paper, we discuss the derivation of partial forces for a traveling monochromatic Alfvén wave, and also suggest a method for deriving more general formulas by expanding the classical formula, known in macroscopic electrodynamic, into the sum of partial forces. The ponderomotive separation of ions is illustrated by the example of the problem for diffusion equilibrium of magnetospheric plasma. We propose a hypothesis that Alfvén waves redistribute plasma along geomagnetic field lines in such a way that the plasma at the magnetic field minima is characterized by an increased content of heavy ions. We suggest that a small admixture of heavy ions exists in the polar wind jet stream. The article is dedicated to the 80th anniversary of the discovery of Alfvén waves.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of spectrum of secondary acoustic-gravity waves in the middle and upper atmosphere in a high-resolution numerical model","authors":"Nikolay Gavrilov, Sergey Kshevetskii","doi":"10.12737/stp-93202310","DOIUrl":"https://doi.org/10.12737/stp-93202310","url":null,"abstract":"Considerable attention has recently been paid to the study of so-called “secondary” acoustic-gravity waves (AGWs) that arise as a result of instability and nonlinear interactions of “primary” wave modes propagating from atmospheric sources, among themselves, and with the mean flow. In this paper, for the first time, the horizontal spatial spectra of primary and secondary AGWs are separated at fixed altitude levels in the middle and upper atmosphere at different time moments, which are simulated using a three-dimensional nonlinear high-resolution model AtmoSym. It is shown that in a short time after switching on the plane wave source at the lower boundary of the model, the spectrum consists of a peak corresponding to primary AGW and quasi-white noise generated by random atmospheric disturbances and the numerical model. Later, secondary peaks appear in the spectra at horizontal wave numbers, which are multiples of the wave numbers of primary AGW. The proposed separation of the spectra of primary and secondary AGWs makes it possible to estimate the relative contribution of secondary AGW at different altitudes, at different times, and with different stability of background temperature and wind profiles in the atmosphere.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136279826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of alpha particles in penetration of solar wind diamagnetic structures into the magnetosphere","authors":"Viktor Eselevich, Vladimir Parhomov","doi":"10.12737/stp-93202302","DOIUrl":"https://doi.org/10.12737/stp-93202302","url":null,"abstract":"We present the results of studies showing the presence of simultaneous jumps in the density of protons (N2/N1)p and alpha particles (N2/N1)α at the boundaries of diamagnetic structures (DS) of various types both in the quasi-stationary slow solar wind (SW) and in sporadic SW. For DS of quasi-stationary slow SW, associated with streamer belt or chains, in the statistics considered in the paper there is a single linear dependence of (N2/N1)α on (N2/N1)p. This means that these jumps have the same physical nature and are related to diamagnetism at the boundaries of DS of quasi-stationary SW streams of various types.
 At the front of interplanetary shock waves (ISW), the (N2/N1)α jump is approximately twice as large as the (N2/N1)p jump. This reflects the features of the collective collisionless plasma heating at ISW fronts and requires further studies. A maximum excess (almost 3 times) of the increase in the alpha-particle density (N2/N1)α over the increase in the proton density (N2/N1)p is observed in eruptive prominences.
 The magnetospheric response in such phenomena as auroras, proton and alpha particle fluxes, geomagnetic field, and geomagnetic pulsations is similar under the influence of DS of various types and ISW. The detected features of the magnetospheric response to the contact with DS of different types and ISW can be interpreted as impulsive passage of the DS matter (plasmoid) into the magnetosphere.
 The results of studies of the (N2/N1)α jumps can be used as an additional important argument in identifying cases of impulsive penetration of DS into the magnetosphere and in examining the physical nature of these penetrations.","PeriodicalId":43869,"journal":{"name":"Solar-Terrestrial Physics","volume":"216 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136280330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}