Cosmic Research最新文献

{"title":"Prediction of Ionospheric TEC during the Annular and Total Solar Eclipses that Occurred over Indonesia by Using OKSM and FFNN","authors":"S. Kiruthiga, S. Mythili, R. Mukesh, Sarat C. Dass","doi":"10.1134/s001095252360004x","DOIUrl":"https://doi.org/10.1134/s001095252360004x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>People across the world have been fascinated by solar eclipses for thousands of years. Solar eclipses are not only fascinating to observe but also provide opportunities for scientific research. During a solar eclipse, the quantity of solar energy reaching the Earth’s surface is reduced as the Moon passes in front of the Sun. This reduction in solar energy can have an effect on the Total Electron Content of the Earth’s ionosphere. In this paper, prediction and analysis of TEC variations in the Ionosphere during the solar eclipses happened on 26.12.2019 between 04:51 to 7:34 hours (UTC) and 09.03.2016 between 12:18 to 1:02 hours (UTC) over the Indonesia region were done by using two models: Ordinary Kriging based Surrogate Model (OKSM) and Feed-Forward Neural Network (FFNN). During the eclipse period, the TEC values were predicted by the OKSM and FFNN models and it is validated using literature. For this study, the GPS data belonging to the BAKO station situated in Indonesia were collected from IONOLAB servers and the input parameters were collected from the OMNIWEB servers. Forty days prior TEC data and input parameters were used to predict the TEC values. The credibility of the predicted results is assessed using statistical factors such as RMSE, CC, MAE, MAPE, sMAPE and R-Square. The statistical results show OKSM has performed well when compared to the FFNN model over the annular and total solar eclipse period. The study suggests that combining multiple modelling methods, such as OKSM and FFNN can improve our understanding of ionospheric variability during solar eclipses and provide more accurate predictions of TEC variations. This has important implications for satellite communications and navigation systems that rely on accurate TEC measurements for positioning and timing.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"1 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Entropy Functionals and Information Difference of Satellite-Monitoring Time Series","authors":"Yu. A. Antonov, V. I. Zakharov, N. A. Sukhareva","doi":"10.1134/s0010952523700429","DOIUrl":"https://doi.org/10.1134/s0010952523700429","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of information analysis of the time series of satellite monitoring of the state of the interplanetary magnetic field provided by the database of the Goddard Space Flight Center. In the arsenal of analysis methods, the main attention is paid to the control of nonextensive properties when scaling time samples created on the basis of the 2001–2022 time series. The reconstruction of the modality of the probability-distribution function for the components of the interplanetary magnetic field in the considered ensemble of realizations is demonstrated. The results of the reconstruction of the kinetics of the Shannon–Boltzmann–Gibbs, Tsallis, and Rényi entropy measures are presented. In a nonextensive approximation, the influence of <i>q</i>-deformation of the phase space on the stochastic regimes of the system under study. In this work, for the first time, the kinetics of information discrepancy and the kinetics of entropy measures of the ensemble of realizations of the values of the interplanetary magnetic field are studied together. The need for approval is indicated by the <i>q</i>-deformation parameters of the phase space, the reference and controlled subsystems, including when using asymptotic approximations in forecasting methods using neural-network algorithms and deep-learning algorithms.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"28 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of Solar-Sail Control When a Vehicle Moves along Cyclic Heliocentric Trajectories","authors":"M. A. Rozhkov, O. Starinova","doi":"10.1134/S0010952523700430","DOIUrl":"https://doi.org/10.1134/S0010952523700430","url":null,"abstract":"","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"65 8","pages":"534-543"},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139239645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Significance of Input Features for Domain Adaptation of Spacecraft Data","authors":"E. Z. Karimov, I. N. Myagkova, V. R. Shirokiy, O. G. Barinov, S. A. Dolenko","doi":"10.1134/s0010952523700466","DOIUrl":"https://doi.org/10.1134/s0010952523700466","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The problem of improving the neural network forecast of geomagnetic index <i>Dst</i> under conditions in which the input data for such a forecast are measured by two spacecraft, one of which is close to the end of its life cycle, and the data history of the other is not yet enough to construct a neural network forecast of the required quality. For an efficient transition from the data of one spacecraft to the data of another, it is necessary to use methods of domain adaptation. This paper tests and compares several data translation methods. Also, for each translated attribute, an optimal set of parameters for its translation were found, which further reduces the difference between domains. The paper shows that the use of domain adaptation methods with the selection of significant features can improve the forecast compared to the results of using untranslated data.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"31 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Prototype of a Background Solar Wind Forecasting Service Based on MHD Modeling and WSA Boundary Conditions","authors":"S. Arutyunyan, A. Kodukov, M. Subbotin, D. Pavlov","doi":"10.1134/s0010952523700508","DOIUrl":"https://doi.org/10.1134/s0010952523700508","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>A prototype service for MHD modeling of the calm solar wind and forecasting the speed and density of solar wind particles in interplanetary space, similar to the NOAA and ESA services, has been created. The service consists of an MHD simulator, a module for processing simulation results, and a web interface. The simulator is based on the implementation of the TVDLF method in the PLUTO package. The boundary conditions of the model (density, radial velocity, magnetic field, temperature) at a distance of 0.1 AU from the origin are obtained regularly from the corresponding NOAA service, in which they are calculated according to the WSA model based on the magnetograms of the GONG network. Two modes of boundary conditions are available: constant and daily. The simulations were carried out on a uniform grid in the range of 0.1–1.7 AU by distance (512 elements), –60°...+60° by latitude (60 elements), 0°–360° by longitude (180 elements). The calculated particle velocity and density maps are compared with the NOAA SWPC and NASA CCMC calculations under the same boundary conditions. A retrospective comparison of the resulting forecasts with data from direct measurements (OMNI) was carried out.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"50 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138543168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Catalog of Geoefficient Flare Events of the Current 25th Solar Cycle in a Modern Presentation","authors":"L. P. Zabarinskaya, V. N. Ishkov, N. A. Sergeeva","doi":"10.1134/s001095252370048x","DOIUrl":"https://doi.org/10.1134/s001095252370048x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>To study the phenomena occurring on the Sun and in interplanetary space and their influence on near-Earth space and on processes in the outer and inner shells of the Earth, the results of continuous long-term observations of solar activity become very valuable. A representative collection of such long-term homogeneous series of systematic observations obtained by the worldwide network of solar and astronomical observatories, as well as by spacecraft, has been collected at the World Data Center for Solar–Terrestrial Physics in Moscow. The article describes a cumulative interactive catalog of the main characteristics of significant solar-flare events of the current 25th cycle of solar activity.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"75 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531241","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of Rotational Motion of the Planet Earth under the Influence of Internal Dissipative Forces","authors":"N. I. Amelkin","doi":"10.1134/s001095252370051x","DOIUrl":"https://doi.org/10.1134/s001095252370051x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The influence of internal dissipation on the rotational motion of the Earth in the gravitational field of the Sun and Moon is studied within the model of M.A. Lavrentiev. The averaged equations of second approximation describing the evolution of the Earth’s rotation axis and the magnitude of its angular velocity are obtained. The dependence of the rate of evolution on the values of the model parameters is studied. Phase trajectories of the evolutionary process are constructed for different parameter values. It is shown that the observed drift of the Earth’s magnetic poles can be explained within the framework of a mechanical model by the angular acceleration of the Earth.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"42 3 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of the Effective Collision Frequency of Electrons in the E and D Regions of the High-Latitude Ionosphere from Analysis of Radio Occultation Measurements","authors":"V. N. Gubenko, V. E. Andreev, I. A. Kirillovich, T. V. Gubenko, A. A. Pavelyev, D. V. Gubenko","doi":"10.1134/s0010952523700491","DOIUrl":"https://doi.org/10.1134/s0010952523700491","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Collisions between electrons and neutral molecules are of special interest for the physics of the Earth’s ionosphere, in particular, for determining the ionospheric conductivity and current systems in the lower ionosphere of the planet, as well as elucidating the role they play in attenuating radio waves propagating inside the <i>D</i> and <i>E</i> regions of the ionosphere. The effective collision frequency of electrons can be estimated from laboratory studies of electron mobility in atmospheric gases in combination with rocket measurements of temperature and particle density in the Earth’s upper atmosphere, or it can be determined independently from analysis of radio occultation data. We have developed a method for reconstructing the vertical profiles of the absorption coefficient of decimeter (wavelength ~19 cm) radio waves by solving the inverse problem of signal absorption in the <i>D</i> and <i>E</i> regions of the Earth’s ionosphere. Based on the analysis of radio occultation data from the <i>FORMOSAT-3</i>/<i>COSMIC</i> satellites, the altitude profiles of the absorption coefficient of decimeter (DM) radio waves in the planet’s ionosphere during the geomagnetic storm on June 22–23, 2015, were determined. It is known that the absorption coefficient at a given fixed frequency is directly proportional to both the electron density and the collision frequency of electrons with ions and neutrals. Using the data on the vertical profiles of the absorption coefficient of DM radio waves and the electron density reconstructed from the analysis of <i>FORMOSAT-3</i>/<i>COSMIC</i> radio occultations, we estimated the effective collision frequency of electrons in the <i>D</i> and <i>E</i> regions of the Earth’s high-latitude ionosphere. The practical significance of studying the frequency of electron collisions and the effects of radio wave absorption in the <i>D</i> and <i>E</i> regions of the planet’s ionosphere is associated with maintaining the uninterrupted operation of space radio communication and navigation systems.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"77 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138543167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Influence of Field-Aligned Currents on Electron Density in the Ionosphere: Combined Observations of SWARM Satellites and ESR Radar","authors":"R. Yu. Lukianova","doi":"10.1134/s0010952523700454","DOIUrl":"https://doi.org/10.1134/s0010952523700454","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results are presented of combined measurements by the <i>SWARM</i> spacecraft (SC) and European incoherent scatter radar on Svalbard for two events of simultaneous observations: in the nighttime ionosphere during substorm activation on January 9, 2014, and in the daytime ionosphere under quiet conditions on February 5, 2017. Onboard magnetometers of the <i>SWARM</i> SC provide measurements of field-aligned current density over the ionosphere. The radar, which is under the flyby trajectory at this time, measures the vertical distribution of the electron density (Ne). Experiments have shown that, under disturbed nighttime conditions, at the location of the field-aligned current flowing from the ionosphere, the plasma density increases throughout the entire slab of the ionosphere and the change in Ne is in agreement with theoretical estimates. In the daytime quiet ionosphere, Ne increases only in the <i>F</i> layer, but practically does not change in the <i>E</i> layer. The differences may be due to the fact that, in the first case, the carriers of the upward directed current are represented by the entire energy spectrum of auroral electrons of 1–10 keV, and in the second case only by the low-energy part.</p>","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"19 1","pages":""},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Features of Narrowband Stimulated Electromagnetic Emission Depending on the Effective Radiated Power of the EISCAT/Heating Facility","authors":"A. Kalishin, N. Blagoveshchenskaya, T. Borisova, I. M. Egorov, G. A. Zagorskiy, A. S. Kovalev","doi":"10.1134/S0010952523700478","DOIUrl":"https://doi.org/10.1134/S0010952523700478","url":null,"abstract":"","PeriodicalId":56319,"journal":{"name":"Cosmic Research","volume":"65 ","pages":"501-509"},"PeriodicalIF":0.6,"publicationDate":"2023-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139241537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}