The Arctic Zone of the Russian Federation is characterized by the rapid growth of the mining industry, aimed at the extraction of oil, gas, coal, and ores, including rare earth metals. Railways are essential in the transportation of these resources to different regions of Russia for processing and export. Part of the cargo delivery is performed via the Arctic ports connected to the railway network. Rapid climate change, including regional climate warming, is among the compromising factors for the operation of the Arctic transport infrastructure. System analysis of climatic processes and assessment of potential hazards that they may induce requires adequate geoinformation support. This paper presents the results of spatio-temporal variability analysis of various hydrometeorological parameters for selected railway mainlines within the Arctic region. For this purpose, a new geoinformation method based on the Hovmöller diagrams was elaborated. This tool is useful for representing climate dynamics along the specified railway mainlines over several decades. It allows us to determine railway sections affected by anomalous climatic conditions on the variable time scale. The presented Hovmöller diagrams proved to be an efficient instrument for the regional climate change representation. It might be quite useful for railway infrastructure maintenance, planning, operation, and adaptation.

We present candidate models for the 14th generation of the International Geomagnetic Reference Field (IGRF-14), specifically the Definitive Geomagnetic Reference Field (DGRF) for epoch 2020.0 and the IGRF for epoch 2025.0. These models were developed using high-quality magnetic measurements from the European Space Agency’s Swarm satellite mission, including data from three low-Earth orbiting satellites equipped with Absolute Scalar Magnetometers and Vector Field Magnetometers. These models are first GC RAS candidates in the IGRF series, where we aim on methodological clarity and incremental innovation, and are part of the CAMPUS project, which is devoted to the construction of a series of Earth’s magnetic field models. Our methodology employs rigorous data selection criteria to minimize contamination from external sources and with strict scalar-vector consistency constraints. The internal magnetic field is parameterized using spherical harmonic functions up to degree 13, with coefficients determined through a two-stage inversion process involving linear inversion of vector measurements followed by nonlinear refinement including absolute scalar intensity data. For the DGRF 2020 model, we utilized data collected between January 2019 and December 2020, while the IGRF 2025 model incorporates measurements from January 2023 to September 2024. Comparison between the models indicates changes in field structure over the 5-year interval, particularly in the South Atlantic Anomaly (SAA) region. These candidate models effectively capture the main features of Earth’s core-generated magnetic field and are consistent with long-term trends observed in previous IGRF generations, contributing to the collective scientific effort to maintain accurate descriptions of Earth’s magnetic field.

Modern satellite positioning and navigation technologies are not applicable in specific areas such as the exploration of oil and gas deposits by means of directional drilling techniques. Here, we can rely solely on natural geophysical fields, such as the Earth’s magnetic field. The precise underground navigation of borehole drilling instruments requires a seamless, near-real-time access to operational geomagnetic data. This paper describes the MAGNUS BD hardware-software system, deployed at the Geophysical Center of the Russian Academy of Sciences, that provides the efficient accumulation, storage, and processing of geomagnetic data. This system, based on the Big Data (BD) technology, is a modern successor of the MAGNUS processing software complex developed in 2016. MAGNUS BD represents one of the first cases of the BD technology’s application to geomagnetic data. Its implementation provided a significant increase in the speed of information processing and allowed for the use of high-frequency geomagnetic satellite data and expanding the overall functionality of the system. During the MAGNUS BD system’s deployment on a physically separate dedicated cluster, the existing classical database (DB) was migrated to the Arenadata database with full preservation of its functionality. This paper gives a brief analysis of the current problems of directional drilling geomagnetic support and outlines the possible solutions using the MAGNUS BD system.

The installation and development of a magnetic observatory can require additional studies of the magnetic properties of construction materials for pavilions and measurement pillars, as well as of the environmental conditions, including, first of all, the magnetic properties of the surrounding rocks. In some cases, detailed studies of magnetic susceptibility can be necessary. To date, these procedures have only briefly been described in the existing manuals and guides. With the development of new construction materials, as well as with the increase in the number of magnetic observatories, the need for such studies has risen even more. This article is focused on studies of the magnetic properties of construction materials for magnetic observatories, and the results are presented based on our experience in the deployment of magnetic observatories and stations in Russia and abroad. An overview of the magnetic susceptibility of different materials is presented. A kappametry method and its application to studies of construction materials are described, and the results of magnetic susceptibility tests performed on the construction materials and the surrounding rocks in the vicinity of an observatory are provided. Finally, some recommendations for studies of materials for observatory construction are given.

The Arctic zone of the Russian Federation is one of the most intensively developing regions of the country. Amongst the major domains of economic and industrial growth and improvement is transport infrastructure and particularly the railway network. This area is being exposed to negative factors of rapid climate change that can significantly affect and compromise this activity. Thus, it is vital to take them into account during design, construction, and operation of the railway infrastructure facilities. This work details the production of a digital atlas comprising the 1950–2021 dynamics of the main hydrometeorological parameters: air and soil temperature, precipitation, wind speed, air and soil humidity, and snow cover thickness. The maps are based on climatic data derived from the MERRA-2 (Modern-Era Retrospective Analysis for Research and Applications, version 2) reanalysis. In total there are 459, which are arranged into 7 chapters. The atlas geographically covers the western part of the Russian Arctic encompassing the regions of quite intensive transport development, which includes the construction of the Northern Latitudinal Railway. Original algorithms of geospatial data processing and their further representation as well as the maps compiled in GIS environment are discussed. Comprehensive analysis of climatic changes in the region of the Russian Arctic including detailed quantitative evaluation over 40 years is given. In the Discussion, we focus on those changes of the regional climate which, from our point of view, are the most significant for consideration by railway operators. The obtained results contribute to framing the theoretical basis of design, development, and sustainable operation of the railway infrastructure in the Arctic and facilitate the decision-making process. This is the first experience of building a specialized climatic cartographic product for the needs of the Russian railways, and to our knowledge the first atlas such as that in the world. In the future, the amassed experience may be transferred to other regions of the Russian Federation as well as similar regions in Canada, Sweden and Highland China that are also subject to significant climate change.

Arctic zone of the Russian Federation (AZRF) is the region of intensive economic development. In this regard, it is critical to give an adequate assessment of natural factors that may have a negative impact on the growing technological infrastructure. Rapid climate change effects show a significant influence on this activity, including the railway network development. Hence, the decision-making community requires relevant information on climatic variations that can put at hazard the construction and operation of railway facilities. This paper presents the analysis of climatic changes within the region of Central and Western Russian Arctic in 1980–2021. It was performed using the new electronic Atlas of climatic variations in main hydrometeorological parameters, created for the Russian Railways in 2023. This geoinformatic product includes about 400 digital maps reflecting the variability of seven climatic parameters over more than four decades within the studied region. These parameters are air temperature, total precipitation, wind speed, soil temperature, soil moisture content, air humidity, and snow cover thickness. The analysis of climatic maps and their comparison between selected periods showed spatial and temporal heterogeneity of climatic variations in this region. This justifies the feasibility of further research using additional analytical instruments, such as Hovmöller diagrams, time series graphs, etc. The implementation of advanced geoinformatic products in the practice of the Russian Railways will facilitate sustainable development of its infrastructure in rapidly altering climatic conditions.

This article presents an algorithm for registering the arrival of tsunami waves based on the operational data of sea level measurements. The algorithm was developed using the fuzzy mathematics approach and implies an expert assessment while the procedure of adjustment and tuning. Its adaptive capabilities allow to function in accordance with the current preceding the arrival of a tsunami wave. The presented algorithm tends to be a universal tool that can be used for detecting the restructuring of processes according to measurements of their characteristics in time.

The K index is one of the oldest universal indices of geomagnetic activity, introduced in 1938 by Julius Bartels, that is still being widely used. Up to the present day, long-term time series of homogeneous K index records have been accumulated at data repositories all over the world. The multidecadal practice of its application makes it an indispensable source of information for the retrospective analysis of solar–terrestrial interaction for nearly eight solar cycles. Most significantly, while studying the historical geomagnetic data, K index data sheets are in certain cases far easier for automated analysis than the conventional analogue magnetograms. The presented collection includes the results of the K index determination at 41 geomagnetic observatories of the former USSR for the period from July 1957 to the early 1990s. This unique collection was formed at the World Data Center for Solar-Terrestrial Physics in Moscow. The historical data, which are offered to the international scientific community, cover the second half of the 20th century and can be used for the retrospective analysis and study of geomagnetic events in the past, as well as for data validation or forecasting (Sergeyeva et al., 2020). The dataset is available at: https://doi.org/10.1594/PANGAEA.922233, last access: 16 September 2020.

A new model has been developed for the density and thickness of the sedimentary cover in a vast region at the junction of the southern part of the East European Platform, the Pre-Caucasus and some structures adjacent to the south, including the Caucasus. Structure and density of sedimentary basins was studied by employing the approach based on decompensation of gravity anomalies. Decompensative correction for gravity anomalies reduces the effect of deep masses providing compensation of near-surface density anomalies, in contrast to the conventional isostatic or Bouguer anomalies. . The new model of sediments, which implies their thickness and density, gives a more detailed description of the sedimentary thickness and density and reveals new features which were not or differently imaged by previous studies. It helps in better understanding of the origin and evolution of the basins and provides a background for further detailed geological and geophysical studies of the region.

Modern satellite gravity missions and ground gravimetry provide operational data models that can be used in various studies in geology, tectonics, and climatology, etc. In the present study, sedimentary basins in the southern part of the East European Platform and adjoining areas including the Caucasus are studied by employing the approach based on decompensative gravity anomalies. The new model of sediments, implying their thickness and density, demonstrates several important features of the sedimentary cover, which were not or differently imaged by previous studies. We found a significant redistribution of the low-dense sediments in the Black Sea. Another principal feature is the increased thickness of relatively low-dense sediments in the Eastern Greater Caucasus. The deepest part of the South Caspian basin is shifted to the north, close to the Apsheron Trough. In its present position, it is almost joined with the Terek–Caspian depression, which depth is also increased. The thickness of sediments is significantly decreased in the eastern Pre-Caspian basin. Therefore, the new sedimentary cover model gives a more detailed description of its thickness and density, reveals new features and helps in better understanding of the evolution of the basins, providing a background for further detailed studies of the region.

In the present study, the structure of sedimentary basins in the eastern Asia Arctic zone is analysed by employing the approach based on decompensative gravity anomalies. Two obtained models, differing in their initial conditions, provide thickness and density of sediments in the study area. They demonstrate essentially new details on the structure, shape, and density of the sedimentary basins. Significant changes in the sedimentary thickness and the depo-centre location have been found for the Anadyr Basin in its continental part. Also, new details on the sedimentary thickness distribution have been revealed for the central part of the Penzhin and Pustorets basins; for the latter, the new location of the depo-centre has been identified. The new model agrees well with the seismic data on the sedimentary thickness for the offshore part of the Chauna Basin confirming that the method is robust. The most significant lateral redistribution of the thickness has been found for the Lower Cretaceous coal-bearing strata in the northern part of the Zyryanka Basin, where the connection of two coal-bearing zones, which was not previously mapped, has been identified. Also, the new details on the sedimentary thickness distribution have been discovered for the Primorsk Basin. Therefore, the new results substantially improve our knowledge about the region, since previous geological and geophysical studies were unsystematic, sparse, and limited in depth. Thus, the implementation of the decompensative gravity anomalies approach provides a better understanding of the evolution of the sedimentary basins and the obtained results can be used for planning future detailed studies in the area.

The article is focused on the approach based on the discrete mathematical analysis conception and continues a series of studies related to the application of the previously developed methodology to geophysical data analysis. The main idea of the study is the modification of earlier conceptions regarding the interpreter’s logic that allows introducing a multiscale approach and performing the time series analysis using the activity measure plots, implying the vertical scale. This approach was used to study the morphology of several intense geomagnetic storms at the final stages of the 23rd and 24th solar activity cycles. Geomagnetic observatory data and interplanetary magnetic field parameters as well as the solar wind flux speed and proton density were analyzed for each of the studied storms using the activity measures. The developed methods, applied to geomagnetic storm morphological analysis, displayed good results in revealing the decreases and increases in various durations and intensities during storms, detecting low-amplitude disturbances, and storm sudden commencement recognition. The results provide an opportunity to analyze any physical data using a unified scale and, in particular, to implement this approach to geomagnetic activity studies.

A nowcasting and even forecast of the auroral oval position and intensity is a highly needed resource for practical applications. The auroral oval is the region with a high level of ionospheric plasma turbulence, which provokes malfunctions of radio communication and navigation satellite systems, and the region with most intense irregular ionospheric electrojet exciting the geomagnetically induced currents (GICs) in electric power lines. We have elaborated a web service (http://aurora-forecast.ru) for continuous nowcasting, visualization and short-term forecast of auroras. The implementation tool of the developed geographic information system (GIS) is the Django framework. The web service is a software shell built on the basis of a virtual globe - a multi-scale digital 3D model of the Earth, rendering visualization of data provided by the NOAA service on the planetary distribution of the probability of the aurora occurrence. The NOAA service uses the output of the OVATION-prime model, which gives a forecast of auroras in advance of 30 minutes with a 5-minute update step, using real-time data from interplanetary monitors of the solar wind. The developed web-service can be used both to assess the probability of observing auroras anywhere in the world. This service may help to predict the deterioration of the satellite navigation signal quality or warn about possibility of intense GICs at high latitudes.

One of the most widely used indices of geomagnetic activity is the K-index. It was proposed in 1938 by Julius Bartels as a measure of the influence of solar corpuscular radiation on the variations of the Earth's magnetic field. Among the essential requirements to indices of this type is its stationarity, i.e., stability of the rules by which it is calculated. Therefore, despite the known disadvantages of the K-index, it is still being calculated according to the method, proposed by Bartels. Historically, at Russian geomagnetic observatories, the K-index has been calculated using simplified methods. In this paper we compare the K-index calculation routine at Russian observatories with the standard K-index and planetary K-index calculation technique.

The International Geophysical Year (IGY) was the most significant international scientific event in geophysical sciences in the history of mankind. This was the largest international experiment that brought together about 300 000 scientists from 67 countries. Well-planned activity of national and international committees was organized for the first time. The history of the IGY organization and complex international experiments in planetary geophysics conducted within its program are discussed in this article. Special attention is given to the estimation of the significance of this project for developing worldwide geophysical research.

This paper presents the results of the creation of a geomagnetic data storage system that combines raw observation data from different geomagnetic observation networks along with derived indices and indicators of geomagnetic activity. Geomagnetic data, provided by observation networks, undergo a series of data quality validation procedures. The implemented instruments and procedures facilitate the creation of a uniform database from multiple sources.

Installation of modern highly sensitive magnetometric equipment at geophysical observatories requires location of places with a low level of magnetic noise.It is also required to perform regular control of noise environment at observatory instrument installation points.This work is aimed at testing one of the prototypes of magnetic noise measuring instruments, capable of performing fast areal measurements.The key features of this prototype are high sensitivity and linearity and capability of registration of magnetic noise in different frequency bands.

Abstract—The paper addresses the variability properties of the intensity and direction of the magnetic field during a substorm as well as magnetically quiet periods. The main focus is on the properties of the variations in the time derivative of the magnetic field dB/dt which are a factor of particular importance for the problem of the geomagnetically induced currents. A method of two- (2D) and three-dimensional (3D) diagrams is proposed for visual representation of the directional variations of a vector field. As an example, the geomagnetic field variations during the isolated substorm of October 17, 2015 are analyzed with the use of the chain of the IMAGE network magnetic stations. It is confirmed that dB/dt in the horizontal plane has a much stronger variability than the geomagnetic field perturbation ΔВ. The proposed 3D diagrams show that the dB/dt polarization plane is inclined towards the Earth’s surface, which is probably due to the irregularity of the field of geomagnetic fluctuations.