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A detailed spatio-temporal analysis of magnetic data was performed during the periods of magnetic storms on October 02, 2013 and September 27, 2019 based on measurements of the station network. In this work, we used a method developed by us for the analysis of magnetic data, based on the use of wavelet transform and adaptive thresholds. The method allows us to identify short-period field disturbances and estimate their intensity from the data of the H-component of the geomagnetic field. The features of the occurrence and propagation of geomagnetic disturbances in the auroral zone and at meridionally located stations have been studied. Dynamic spectra of disturbances of different intensity and duration are obtained. The paper confirms the possibility of occurrence of short-period weak geomagnetic disturbances at stations from high latitudes to the equator, preceding magnetic storms and correlating with fluctuations of the southern Bz-component of the interplanetary magnetic field and increases in the auroral indices of geomagnetic activity. Cross-correlation dependences of the intensity of geomagnetic disturbances on the parameters of the interplanetary medium during magnetic storms were obtained from the data of the network of magnetic stations. A statistically significant influence of the magnitude of the scope of the Bz-component of the IMF and the speed of the solar wind on the development of magnetic storms during the initial and main phases of magnetic storms was revealed.

Investigation of interactions of the near-planet space parameters, Earth magnetic field and ionospheric parameters are of interest in the tasks of solar-terrestrial physics and applied researches related to space weather. Ionosphere is one of the important factors of space weather. Functioning of modern ground- and satellite-based engineering facilities depends much on its state. The paper makes a statistical estimate and analyzes complex effect from interplanetary magnetic field parameters, solar radiation and geomagnetic data on ionospheric disturbance development. Ionospheric disturbances were estimated on the basis of the method developed by the authors. The method applies wavelet transform and adaptive thresholds. The most significant factors of ionospheric disturbance occurrences were detected during the investigation and their significance was evaluated.

A method for analyzing natural data and detecting anomalies is proposed. The method is based on combining wavelet filtering operations with the NARX neural network. The analysis of natural data and the detection of anomalies are of particular relevance in the problems of geophysical monitoring. An important requirement of these methods is their adaptability, accuracy and efficiency. Efficiency makes it possible to detect anomalies timely in order to prevent catastrophic natural phenomena. Wavelet filtering operations include the application of a multi-scale analysis construction and threshold functions. The article proposes a wavelet filtering algorithm and a method for estimating thresholds based on a stochastic approach. The operations of the method implementation are described. It is shown that the use of wavelet filtering allows one to suppress noise, simplifies the data structure and, as a result, allows one to obtain a more accurate NARX neural network model. The effectiveness of the method for detecting ionospheric anomalies during periods of magnetic storms is shown using the data of the critical frequency of the ionosphere as an example. [ABSTRACT FROM AUTHOR]

We present and describe an automated method for analysis of magnetic data and for detection of geomagnetic disturbances based on wavelet transformation. The parameters of the computational algorithms allow us to estimate the characteristics of non-uniformly scaled peculiar properties in the variations of geomagnetic field that arise during increasing geomagnetic activity. The analysis of geomagnetic data before and during magnetic storms was carried out on the basis of the method according to ground station network. Periods of increasing geomagnetic activity, which precede and accompany magnetic storms, are highlighted. The dynamic of geomagnetic field variation in the auroral zone is considered in detail.

Based on the ground station data, the paper investigates the dynamics of space rays and ionospheric parameters during strong and moderate magnetic storms 2018. The research was carried out applying new methods for modeling and data analysis suggested by the authors. In the course of investigation, anomalous changes in ionospheric parameters preceding and accompanying magnetic storms were detected. When they were compared with the data of cosmic rays and interplanetary magnetic field, correlation was observed. It confirms the solar nature of the detected ionospheric effects. Application of regression methods confirmed the assumption on statistically significant effect of interplanetary magnetic field parameters on ionospheric parameter dynamics during increased solar activity. The results are of interest in the tasks of space weather forecast.

In the present paper, we have carried out an analysis of the ionospheric critical frequency data of the F2 layer during strong magnetic storms in 2017-2018. The ionospheric data of Paratunka (IKIR FEB RAS, Kamchatka, 53.0 N, 158.7 E), Wakkanai (Japan, 45.16 N, 141.75 E), and Moscow stations (Russia, 55.49 N, 37.29 E) were used. The study was carried out using a generalized multicomponent model (GMCM) developed by the authors. GMCM allows studying the dynamics of the ionospheric parameters in detail and estimating their characteristics. Using the modeling, we detected and studied anomalous changes in the ionosphere preceding and accompanying the periods of magnetic storms in the analyzed areas. The study results were compared with the traditional median method and showed the perspectiveness of GMCM. The research is supported by a grant from the Russian Science Foundation (project No. 14-11-00194).

The dynamics of geomagnetic field variations on the eve and during the periods of magnetic storms of 2015 and 2017 has been studied (data of the horizontal component of the Earth’s magnetic field of the terrestrial station network were used). The method developed by the authors based on wavelet transform and adaptive threshold functions was applied. Weak geomagnetic disturbances synchronously appearing at the stations and preceding the onset of strong magnetic storms was extracted. The correlation of the isolated geomagnetic disturbances with the AE-index is shown, both in the occurrence times and in intensities. On the basis of comparison with interplanetary environment data (interplanetary magnetic field data and the solar wind parameters were analyzed), and also based on the results of other author works [1, 2]. we assume that the isolated effects have solar nature. The research is supported by the grant of the Russian Science Foundation No. 14-11-00194.

The paper suggests a new technique for magnetic data analysis to detect and to estimate short-time anomalous increases in geomagnetic disturbance intensity. Based on the technique and applying the data of meridionally arranged stations in the north-east of Russia («Kotel’nyi» KTN, «Tixi» TIX, «Chokurdakh» CHD, «Zyryanka» ZYK, «Mys Shmidta» CPS, «Yakutsk» YAK, «Magadan» MGD, «Paratunka» PET, «Khabarovsk» KHB) and the near equatorial Indian stations (“Hyderabad” HYB and “Choutuppal” CPL), we analyzed the geomagnetic field variations during strong magnetic storms. This approach allowed us to detect simultaneously occurring local increases in geomagnetic activity observed a few hours before events and during the main phases of magnetic storms. The development of the method was supported by RSF Grant No.14-11-00194. Experimental investigations were supported by RFBR Grant No. 16-55-45007.

The paper presents our software system for estimation the degree of disturbance of the geomagnetic field. The system automatically classifies registered geomagnetic data and determines the state of the geomagnetic field for the current day. The results of approbation of the system showed the prospect of its application in problems of estimation and prediction of space weather. The system allows us to allocate weak disturbances of the geomagnetic field, which may occur before strong magnetic storms.

The paper shows new methods of analysis of ionospheric and magnetic data applying the models of multicomponent constructions (MCM models) developed by the authors. Based on ground station data, the analysis of ionospheric and magnetic data during increased solar activity was carried out.

Since their discovery, cosmic rays have been an integral part of the development of fundamental physics, from the discovery of radiation coming to the Earth from outer space and the identification of high-energy particles in it, as well as new fundamental symmetries in the laws of nature, to the knowledge of residual matter and magnetic fields in interstellar space. Cosmic rays are used in a number of fundamental and applied research in solar-terrestrial physics and are important in the research of the near-Earth space processes. Cosmic ray variations observed on the Earth's surface are an integral result of various solar, heliospheric, magnetospheric and atmospheric phenomena. The most significant changes in cosmic ray parameters are caused by coronal mass ejections and subsequent changes in the parameters of the interplanetary magnetic field and solar wind. Therefore, the study of cosmic rays makes it possible to obtain valuable information about the processes in the near-Earth space and in the Earth's magnetosphere during disturbed periods. This article proposes a method for analyzing cosmic ray variations. It is based on the use of wavelet data decomposition operations and their combination with threshold functions. By using adaptive thresholds, the operations for detecting anomalous changes in data and for suppressing the noise were developed. Anomalies in cosmic rays can cause radiation hazard for astronauts, radio communication failures, as well as malfunctions in satellites, leading to the loss of orientation and destruction. Therefore, the task of timely diagnostics of anomalies is urgent. The paper describes the algorithms for the implementation of the method and shows their application in the space weather problem. We used data from the network of ground stations of neutron monitors. The efficiency of the method for detecting abnormal changes of different amplitudes and durations is shown. Application of the method made it possible to detect clearly and to evaluate Forbush effects in cosmic rays, which precede the onset of magnetic storms of various nature and strength. [ABSTRACT FROM AUTHOR]