Home – Home – Jornals – Atmospheric and Oceanic Optics 2023 number 3

The correlation between the sedimentologic characteristics of the Upper Triassic deposits of Wrangel Island and the Chukchi Peninsula (Chukotka) is discussed. These deposits are similar in isotopic, petrographic, and geochemical features. It has been established that the Upper Triassic sand strata accumulated at different sites of a single sedimentary basin, in shallow-water prodeltas of Wrangel Island and in deeper-water environments of Chukotka. In the latest Triassic, the portion of the sand component in the sections increased. At the same time, the average size of the sand grains decreased, which indicates weakening of the tectonic factor in some zones of the provenance and its general peneplanation with the formation of a weathering crust. The eroded complexes are composed of granitoid, metamorphic, and metavolcanic rocks. They stayed on land for a long time, being subjected to chemical weathering. The depth intervals with the large amount of sandy material in the section of Wrangel Island and Chukotka are correlated with those in the sections of the Sverdrup Basin and the northern slope of Alaska.

The paper presents data on the classification, structure, and biota of reef complexes from the Late Ordovician--early Silurian Altai Basin. The early Paleozoic history of the Altai Basin included the early--middle Katian, late Katian, early Hirnantian, late Telychian, and middle--late Sheinwoodian events of large-scale reef formation which produced framework reefs, mud mounds, and coral meadows. The early Paleozoic reefs of the area formed at rates of 40 to ~12 cm per thousand years. The late Telychian reef system, which formed in 0.5-1.0 Myr, occupied the largest area of the basin. The lateral extent of reef systems in the Late Ordovician-early Silurian basin of Altai depended more on the rates of vertical and lateral growth, as well as on the previous sea bottom topography and clastic inputs, than on the duration of reef formation. Carbonate deposition in the Altai basins of that time can be simulated with a general model implying formation of distal barrier reefs.

The study area is located within the Chernyshev Ridge, a fold-thrust structure, which is a promising area for oil and gas exploration in the Timan-Pechora province. Petroleum source rocks of Paleozoic (from Upper Ordovician to Lower Carboniferous) deposits stripped by the Vorgamusyur-1 well in the Talbei block of the Chernyshev Ridge were studied by lithological, petrographic, organic-petrology, and organic-geochemistry methods. Most of the section is characterized by low values of C_org (<0.5%), genetic potential (S₁ + S₂ < 0.5 mg HC/g rock), and hydrogen index (HI < 100 mg HC/g C_org). Petroleum source rocks with elevated values of C_org (up to 0.9%), S₁ + S₂ (up to 2.1 mg HC/g rock), and HI (up to 277 mg HC/g C_org) were identified at different stratigraphic levels of the section: Upper Devonian (D₃tm-sr), Upper Silurian (S₂gj), and Upper Ordovician (O₃mt). The maceral composition of organic matter (OM) and the distribution of hydrocarbons in the saturated fraction of bitumens indicate that petroleum source rocks include only marine OM (type II kerogen). The catagenetic transformation of OM was assessed based on the bituminite reflection (RV_eq), Rock-Eval pyrolysis temperature (T_max), and conodont color alteration index (CAI). The available RV_eq (0.63-0.84%), T_max (430-443 °C), and CAI (1.5-2.0) data indicate that the entire Paleozoic well section is in the oil window (MC₁-MC₃). The new data refined the catagenetic zonality of the sedimentary section, according to which the OM reached the following gradations: MC₁ in the lower Carboniferous and Famennian deposits, MC₂ in the interval from the Frasnian to the upper part of the Lower Silurian, and MC₃ in the Lower part of the lower Silurian and in the Upper Ordovician. The results of a study of petroleum source rocks and the type and maturity of OM will be the basis for basin modeling, which will increase the reliability of reconstructions of oil and gas formation at the Chernyshev Ridge.

Based on new data on the geology, composition, U-Pb isotopic age, and paleomagnetism of the metavolcanic rocks of the Kataevo Formation, we consider the geodynamic conditions of their formation and alteration. The Kataevo Formation metavolcanic rocks belong to the K-Na-high-alumina andesite-andesibasalt-basalt volcanic series. Results for U-Pb analysis of magmatic zircon (SHRIMP II, 8 spots) from a metaandesibasalt sample of the stratotype section on Ungo R. yielded and age of 852 ± 9 Ma. Isotope systems for Sm-Nd yield a positive ε_Nd(852) = + 9.29, which indicates a juvenile magmatic source, close to depleted mantle (DM), with a Neoproterozoic protolith T_Nd(DM) model age. The content of the less mobile HFSE and REE (ppm) is consistently low for Nb (8-15), Ti (7074-12,410), Ta (0.32-0.93), Eu (1.80-2.29), Се (50-79), Y (21-25), Yb (2.1-2.8), Rb (10-24) and elevated for Sr (1000-1500), Zr (170-270), La (25-41), and Ba (600-800). All studied parameters place the metavolcanic rocks close to the contemporary Kurile-Kamchatka type of developed island arcs. Paleomagnetic analysis of the section of metavolcanic rocks shows a complete remagnetization ca . 120 Ma. This is synchronous with manifestations of intraplate basaltoid magmatism in the studied region, the most typical example of which is the Lower Cretaceous Khilok Formation.

We present the first results of a comprehensive isotope-geochemical study of dolomitic carbonatites of the Mal’dzhangarka massif located in the southeast of the Billyakh melange zone (southeastern periphery of the Anabar Shield). Zircon grains separated from core samples from a depth of 6-30 m have a three-phase structure. All of them were trapped from the host metamorphic rocks and mark the age of the main stage of high-gradient metamorphism in the region, 2027 ± 9 Ma. Pyrochlore containing 38-705 ppm U and 5-21 ppm radiogenic Pb, with weak metamictization of the crystal lattice and an undisturbed U-Pb system, made it possible to estimate the concordant age of rare-metal mineralization in the massif, 167 ± 4 Ma, which is probably close to the crystallization age of the host carbonatites. The estimated age corresponds to one of the stages of kimberlite-carbonatite magmatism on the eastern slope of the Anabar dome. The Rh-Os isotope system of pyrite from superposed late carbonate-sulfide veinlets in the carbonatites testifies to a close (within the error of determination) age, 179 ± 14 Ma, and a low initial Os isotope ratio, which indicates the contribution of mantle material to the formation of this isotope system.

The paper discusses current state of the spectral approach to analysis of induced polarization (IP), its possibilities and limitations, along with directions for the method development. Reviewed are the main methods and approaches for estimation of spectral IP parameters and their specific features. Our practical experiments have shown the advantages of analysis of transient IP characteristics over standard approaches to the IP data analysis and processing. Results of the standard and spectral approaches application to analysis of IP data when solving mineral exploration problems at the Maletoyvayam gold deposit (Kamchatka Peninsula) and the Yasnoe gold occurrence (Taimyr Peninsula) are compared. Here, we demonstrate that low efficiency of works is erroneously regarded as one of the main factors hindering a broad adoption of the spectral IP method in mineral exploration activities. Rather, it is a lack of automated techniques for analysis of transient IP characteristics. We propose a new approach to spectral analysis of IP data, based on the algorithms for image recognition of a reference object, and describe pioneering efforts of its practical application.

Possibilities to construct the sections of thermal conductivity, specific heat capacity, as well as heat flow density at the surface, using electromagnetic sounding data and laboratory measurements on core samples, have been studied. It has been shown that neural network prediction of thermophysical properties from electromagnetic sounding data and laboratory measurements enables estimating these properties not only below boreholes but also in the interwell space, with relative accuracy around 6-10 %. Sections of «dry» and «warm» thermal conductivity, specific heat capacity and a profile of the heat flow density at the surface of the study area, along magnetotelluric sounding profile, have been built.

The study addresses basic problems of modern geodynamics and seismicity of the Central Asian lithosphere. It aims at predicting dynamic effects of large earthquakes for seismic safety of the Baikal-Mongolian region. Special focus is made on the seismic behavior of areas where seismic risk zoning is problematic because of permafrost. The paper presents synthesis of previous and new data on ground responses to large earthquakes in specific territories of the Baikal-Mongolia region with complex cryological conditions. The results include shaking intensity patterns and predicted seismic parameter values for degraded permafrost in zones of different climates and seismicity levels. The obtained prediction maps can make reference in studies of variable permafrost responses to temperature, seismic, and mining-related impacts.

Recent results on continuous-wave bismuth-doped fiber lasers for a wavelength region of 1.3 - 1.5 μm pumped with laser diodes (multimode semiconductor laser diodes) are presented. A concept of the development of such devices by an example of the laser level scheme is considered. The main features of operation of cladding-pumped bismuth-doped fiber lasers and their performance characteristics (efficiency, output power, stability) are discussed. In addition, the possibility of optimizing the parameters of these devices by changing the geometry of the inner cladding and dual-wavelength pumping is considered.

Generation of ultrashort mid-infrared pulses in Raman gas fiber lasers is investigated. Using a hollow-core revolver fiber filled with a mixture of molecular deuterium and hydrogen gases, Raman generation of ultrashort pulses at λ = 3.9 μm is realized for the first time. The pulse duration of 4.6 ps is obtained, and the pulse energy as high as 10 μJ is achieved at λ = 3.9 μm.

We review our development of wavelength tuneable, high average power, picosecond-pulse, mid- infrared sources in the three micron widow for proposed application in tissue ablation studies and with the objective of source simplification and exploring the potential of all-fiber integration. Initial systems were based on difference frequency generation (DFG) of two synchronous master oscillator power fiber amplifier (MOPFA) schemes. The generated idler was tuneable over the range 3.28-3.45 µm, delivering greater than 3 W of average power, with a maximum pump to total DFG power conversion efficiency of 78 %. By simplifying the seed sources through synchronised in-line modulation of cw diode laser sources, more than 6 W was generated 3.31-3.48 µm with similar efficiency and with near diffraction limited beam quality (M2 = 1.4). In an improved and significantly simplified experimental configuration a source emitting around 3 µm was developed employing a novel χ⁽³⁾/χ⁽²⁾ cascaded nonlinear conversion architecture. Picosecond pulses from a 1.064 µm mode-locked Yb:fiber pump laser were used to generate 1.65 µm signal pulses through χ⁽³⁾ based four-wave mixing in a polarisation preserving photonic crystal fiber (PCF). The output of the PCF was then directly focused into a periodically poled lithium niobate crystal, generating idler radiation around 3 µm, with peak powers of ̴ 0.5 kW, via χ⁽²⁾-based three-wave mixing between the pump and signal pulses.

Quantum squeezed states of light, characterized by a reduced quantum uncertainty in one of the quadrature variables below the uncertainty of the vacuum state (below the standard quantum limit), play an important role in modern fundamental and applied research. This paper provides basic information about the properties and manifestations of squeezed states. A brief review of methods for obtaining and detecting quantum squeezed light is given, with special attention paid to fiber systems. The Kerr mechanism for generating squeezed states, which is implemented in various variants of fiber systems, is considered in detail. An experimental scheme for generating polarization-squeezed states based on a polarization-maintaining nonlinear fiber is presented. Various factors limiting squeezing are considered.

Nonlinear optics in multimode fibers (MMFs) has had a renaissance over the past two decades, driven by both basic and applied research. MMFs provide an ideal setting for studying multidimensional systems with their complicated collective dynamics. The uniqueness of MMF including the spatial degree of freedom, spatiotemporal dynamics, and inherent disorder make them an ideal tool for exploring novel physics beyond communication. Here, we briefly discuss an overview of nonlinear dynamics in MMFs by focusing their applications in spatiotemporal pulse shaping, self-beam cleaning, and broadband continuum generation. The nonlinearities in MMFs can be useful in linear and nonlinear imaging in microscopy and endoscopy configurations. The growing interest among researchers for nonlinearity in MMFs fibers is pretty evident, indicating a growth in the value of MMFs.

We overview our recent experimental studies on the nonlinear spatial reshaping of multimode beams at the output of multimode optical fibers. We use a holographic mode decomposition technique, which permits us to reveal the variation of the spatial mode composition at the fiber output, as determined by either conservative (the Kerr effect) or dissipative (Raman scattering) nonlinear processes. For the first case, we consider the effect of spatial beam self-cleaning, and we compare experimental mode decompositions with predictions based on the thermodynamic theory, including the case of beams carrying nozero orbital angular momentum. For the second case, we analyze the beam mode content at the output of a Raman laser based on a graded index multimode fiber.

We experimentally and numerically demonstrate the inability for picosecond telecom pulses to form a single multimode soliton in a graded-index fiber. This property is useful in space-division multiplexed systems, to transmit independent soliton channels which do not merge into a single multimode soliton.

The paper overviews new means of photonics based on the use of stimulated Brillouin scattering (SBS) in optical fibers. The main attention is paid to the original configurations of narrow-band low-noise lasers and their potential applications for distributed fiber-based measurements.

A review of major noise processes affecting the operation of phase-sensitive coherent reflectometers is given. The overview may be useful for educational purposes. The measurement results obtained using modified single-mode fibers with artificial scatterers distributed along the fiber length are presented. The advantages of such fibers over the standard single mode fibers are demonstrated and analyzed. The relationship between the phase noise of the reflectometer signal and that of the probing laser is shown.

In this work, spectral and phase properties of dynamic population gratings in various samples of ytterbium fibers are studied at various powers of recording and pumping radiation. It turned out that, despite differences between the samples, power dependences have a similar character, which is determined by the gain in the fiber and the saturation power in it. It is shown that the phase of the dynamic grating takes on a constant value, changing it only at the instant of the transition from the absorption grating to the gain grating. Significant influence of the phase component in dynamic population gratings in ytterbium doped fibers is experimentally shown.

Under the action of light in plasmon resonance conditions, metal nanoparticles induce heat at the nanoscale. This effect forms the basis for thermoplasmon probing of phase changes occurring in nanoscale systems, the study of which is a key task in modern material science. Despite the obvious simplicity of this approach, enhanced absorption of light by resonant nanostructures does not guarantee the desired optical heating in cases where the thermal conductivity of the medium significantly exceeds the thermal conductivity of the plasmonic nanostructure. We propose an approach for creating controlled heating of plasmonic nanostructures by nanostructuring the surface of a thermostat, which is demonstrated using a thermoplasmonic metasurface, which is an array of TiN:Si voxels - a vertical system of titanium nitride (TiN) and silicon (Si) nanostructures on a silicon substrate. Plasmonic TiN nanostructures play the role of nanoheaters, and varying the height of silicon heat conductor makes it possible to control the temperature of heating of voxels at a fixed value of the pump intensity by controlling heat localization. A possibility of probing phase transitions in nanoscale systems is demonstrated by an example of thin polymer films using a thermoplasmonic metasurface and Raman spectroscopy.

Optical heat generation and control at the nanoscale play a key role in many applications, such as photothermal therapy, photocatalysis, thermophotovoltaics, etc. Adjusting the photoheating temperature can be easily performed by tuning the intensity of the incident light. However, fine tuning of the temperature of nanostructures at a fixed light intensity still remains a challenging task. In this work, we propose a tunable optical nanoheater that consists of a titanium oxynitride (TiON) plasmonic antenna placed on top of a silicon cylinder. It has been experimentally shown that, at a fixed intensity of 5 MW/cm², a change in the photoheating temperature up to 100 ^◦C can be achieved. The underlying approach is based on the controlled oxidation of TiON. This allows for flexible tailoring the permittivity of TiON. As a result, the photoheating temperature can be tuned, which is associated with the modification of the absorption cross-section of plasmonic nanostructure.

Three-dimensional ab initio potential energy surfaces of the interacting triplet states ³ A ₂ and ³ B ₁ of the О₃ molecule are constructed within the diabatization approach implemented in the MOLPRO package. These two states are responsible for the strongest singlet-triplet transitions in the Wulf band of O₃. The molecular orbitals are optimized by the state-averaged CASSCF with the active space CAS(18, 12) involving three electronic states ( X ¹ A ₁, ³ A ₂, and ³ B ₁). The correlation energy is computed by icMRCI(Q). The impact of the basis set size on the accuracy of both the adiabatic excitation energy and origins of the vibronic transitions is analyzed.

From the known experimental data, the parameters of the non-polynomial analytical model γ(sur) for the broadening coefficients γ of the ammonia molecule absorption lines by the pressure of helium, argon, nitrogen, oxygen, air, hydrogen, carbon dioxide, and its own pressure are determined. The accuracy of the experimental data recovery by the model γ(sur) varies from 3.3 (nitrogen broadening) to 8.5% (carbon dioxide broadening). The comparison with the polynomial representation and with the results of calculations of these coefficients by the semi-classical method is made.

The criterion for stopping the intensity collapse is established in the approximation of the nonlinear Schrödinger equation for the problem of self-focusing of high-power femtosecond laser radiation in an optical medium. Using propagation of a femtosecond laser pulse in air as an example, it is shown that the collapse stops when the role of diffraction increases due to a decrease in the radius of the laser beam, and occurs not at a point, but at an interval in front of the nonlinear focus, where the self-phase modulation of the radiation due to the plasma nonlinearity prevails over the Kerr effect. The result (collapse stop criterion) makes it possible to take into account the features of the nonlinear activity of various optical media during the propagation of high-power femtosecond laser pulses; in particular, the role of nonlinear absorption is determined under the conditions considered.

We present the results of the assessment of multiyear variability for the parameters of single-layer cloud fields over the territory of Western Siberia in summer in 2001 to 2019 based on MODIS data. The seasonal average proportion of coverage by single-layer clouds of different types and values of their features are determined based on the results of cloud classification from summer (June, July, August) daily satellite images of the target region. Parameters of single-layer clouds are considered for three latitudinal zones of Western Siberia: southern (< 60° N), transitional (60-65° N), and northern (> 65° N). We found linear trends of the proportion of coverage by different single-layer cloud types and of their parameters: optical thickness, effective particle radius, waterpath, and cloud top height. A discussion of the results is given. The greatest variability of the physical parameters considered in this work is characteristic of the vertical development and low-level clouds in the northern and transition zone of the target region. The effect of anomalous blocking anticyclones on some features of different cloud types in the considered latitudinal zones of Western Siberia is shown.

Quantitative estimates of changes in wind energy resources in the high latitudes of the Northern Hemisphere are obtained using ERA5 reanalysis data for 1979-2021. The wind energy potential (WEP) was estimated during the analysis. According to the ERA5 reanalysis data, a marked increase in the WEP over the Greenland, Norwegian, Barents, Kara, and Chukchi Seas, as well as over the European territory of Russia in winter, over the Kara and Norwegian Seas in spring, and a general increase in WEP along the Arctic coast, in particular over its Russian sector in summer and autumn, are noted under the current climate regime. The noted changes in WEP quite well correlate with the retreat of sea ice in the Arctic, as well as with the leaf area index, which characterizes the roughness of the underlying surface in the high latitudes of the Northern Hemisphere. The increase in the proportion of the year when wind generators are capable to operate over the Russian Arctic makes the region quite promising for the use and development of wind power in the context of the climate change.

This paper is devoted to assessing the long-term variability of the parameters of sudden stratospheric warmings (SSW) from 1979 to 2021. The values of the mean zonal air temperature at a latitude of 80°N and zonal average wind speed at 60°N at altitudes of 10 hPa are used as a criterion for estimating the SSW. Major SSWs are classified according to their types - with split of the polar vortex (PW) and with PW displacement. Estimates are made of the variability of such SSW parameters as the number of events per winter, SSW type, SSW duration, start date and maximal temperature during SSW over the past 42 years. No trend changes are found, but oscillatory behavior of the parameters is observed in the high-latitude stratosphere.

The results of experiments carried out in the Large Aerosol Chamber of IAO SB RAS during 2021-2022 to study the optical characteristics of smoke aerosol with a long aging time (up to 2-3 days) are presented. The influence of the evolution of optical characteristics of pyrolysis and mixed smokes on the radiative forcing of smoke aerosol (RFA) at the top of atmosphere in the Arctic region in summer is estimated. It is shown that for pyrolysis smokes, the main factor that determines the time dependence of RFA is the evolution of the aerosol optical thickness, while for mixed smokes, it is also necessary to take into account the temporal variability of the single scattering albedo of aerosol particles. The dependence of RFA on underlying surface types and illumination conditions typical for the Arctic region is considered for different modes of biomass combustion.

An original statistical model of laser pulse propagation in a scattering medium is considered, which makes it possible to calculate the power of a lidar signal taking into account scattering effects of any multiplicity. A comparative analysis of the temporal structure of the signal obtained using the model suggested and alternative methods is carried out. The features of the propagation of a laser pulse from a ground-based lidar in continuous cirrus clouds are studied taking into account the effects of multiple scattering. The dependence of the multiple scattering background on the cloud optical and microphysical characteristics (extinction coefficient, degree of roughness, size and shape of ice particles) and parameters of the lidar receiving system is studied. The simulation results indicate a high sensitivity of the part of the echo signal due to multiple scattered light to variable parameters, which should be taken into account when setting and solving inverse problems.

The applicability of semiconductor methane sensors, designed to detect explosive concentrations of gas in rooms, to the study of background concentrations of methane in the atmosphere and its emissions from the water body surface is studied. An experimental prototype of the methane sensor is designed, for which, in order to increase the accuracy of determining the methane content in air, a calibration plan is suggested, which takes into account the humidity, temperature, and pressure of the environment. Laboratory and field experiments show that the TGS series sensors are capable of detecting methane concentration changes from 0.1 ppm and higher and can be mounted in floating chambers used to determine methane emissions from the water surface. An experimental setup is described. The results of calibration and selection of the best parametric model are presented. Recommendations for further development of the device are given.

The paper presents the results of the development of an active optical system (a laser monitor) to form enhanced images simultaneously in the visible and near-IR spectral regions. Imagining is carried out in the active medium of a manganese atom brightness amplifier. Images are formed for a time corresponding to the amplification (generation) pulse, which is about 25 ns for the visible region and 35 ns for the IR. Image recording is carried out using digital cameras, including those based on a Russian-made InGaAs sensor. Images of processes accompanied by background radiation formed by a single pulse of a brightness amplifier based on manganese chloride vapors are shown for the first time.

Methods for measuring the salinity of seawater are considered. The results of an experimental study of samples of common and sea salt solutions with different salinity, poured into a hollow trihedral optical glass prism are presented. To measure the angles of refraction of light, a goniometric system was used, the minimum deviation method was implemented, which has a high accuracy of determining the refractive index. With dispersion analysis of experimental results, it is proved that the refractive index of water does not depend on its salt composition. An equation is suggested which describes the dependence of the refractive index on salinity and temperature for a fixed wavelength.

This study focuses on the process of the COVID-19 pandemic spread across Siberia in 2020-2021, using the case study of 15 constituent entities of the Russian Federation. Its purpose has been to explain the mechanism of coronavirus penetration into Siberia and the resulting excess mortality proceeding from the distinctive features of Siberian regions’ space. The novelty of our approach consists in using the most reliable monthly excess mortality statistics for characterizing the demographic impact of the pandemic, regional regulatory legal acts of antiviral nature, and the concept of spatial diffusion of innovations to characterize pandemic waves in the regions of Greater Siberia. The main findings are as follows. First, five types of Siberian regions have been singled out in terms of integral demographic damage from the pandemic in 2020-2021: Khanty-Mansi Autonomous Okrug and Yamalo-Nenets Autonomous Okrug for the highest excess mortality; Omsk, Novosibirsk, and Tyumen Oblasts for moderately high; Tomsk Oblast, Altai and Krasnoyarsk Krais for relatively high; Irkutsk and Kemerovo Oblasts, Altai Republic, Republics of Khakassia and Buryatia, and Zabaykalsky Krai for below the national average; Republic of Tuva for extremely low excess mortality throughout the entire pandemic. Second, four types of regional spatial systems in Siberia have been identified according to the degree of vulnerability to coronavirus diffusion: most vulnerable open polycentric; highly vulnerable open centralized; moderately vulnerable closed centralized; least vulnerable closed polycentric. Third, it has been found that for the first type, crucial for pandemic spread was relocation spatial diffusion (and its particular characteristic case of rotational migration); the second type had relocation (by plane) and horizontal (within the local labor market); the third and fourth types had horizontal spatial diffusion as the most prominent factor. Conventional factors, such as industry specialization, population density, and Siberian-specific transport infrastructure, had little effect on coronavirus incidence. Much more important was the (contact-intensive) communication slice of these factors, which determined the potential and rate of pandemic spread in Siberian regions.

The effectiveness of metropolitan area management has not yet been extensively studied. The article proposes to evaluate it in relation to the inter-communal cooperation model based on three components, i.e., evaluate the overail effectiveness of managing the area’s development as the degree to which the goals of agglomeration interaction are achieved, “political" effectiveness of decision-making and implementation, and “managerial" effectiveness of agglomeration projects implementation. Along with the theoretical justification of the approach, the article presents the research results on the effectiveness of managing metropolitan areas in Chelyabinsk Oblast.

The article examines in detail how the Asian part of Russia develops spatially, the geographical unit of analysis being municipal formations. Based on the study of distributed characteristics of economic development, we conclude that there is heterogeneity and inconsistency in Russia’s development in the east, both in latitudinal and meridional dimensions. The influences of resource, geographic, infrastructural, agglomeration, and market factors on the development of municipalities in Russian Asia are assessed using econometric methods. Our sample includes 271 municipalities, and the observation period covers the period between 2015 and 2018. Regression estimates have shown that the resource economy and natural rents continue to play an important role in the eastern economy. However, despite the low business density and high transport costs, agglomeration and market factors show significance and shape the spatial proportions of Asian Russia. The market mechanism influence is ambiguous: while depletion dominates interactions between regional centers and their environs, horizontal inter-municipal relations create a positive effect, which overrides the negative impact caused by the rest of the region’s engagement with its capital. The results obtained are arguments in favor of strengthening the macro-region space connectivity and supporting inter-regional and inter-municipal cooperation. The solution to this problem includes both a technical component, involving the infrastructure projects, and an institutional one, aimed at strengthening cooperative and reducing competitive incentives for spatial interaction.

The article tests hypotheses about how place branding initiatives impact the number of attracted tourists and revenues of the tourism and recreational sector in Russia’s constituent entities. For this purpose, we perform a difference-in-differences estimation on their panel data to find the average effect of place branding on increasing the number of guests in collective accommodation establishments and the value-added of hospitality industry enterprises. The results show that the implementation of place branding initiatives is associated with an average growth in the number of tourists attracted by 15.7%, and the level of income from serving them escalates with a more dynamic brand promotion policy. However, such positive effects are observable mostly in the early years of place branding initiatives. Achieving long-term goals to raise the income of the region’s tourism and recreation sector, therefore, requires not only place branding but also more capital-intensive measures to develop tourist infrastructure, create new facilities, and hold events that could be an incentive to visit the region.

The article briefly describes the natural population movement in Russia between 1980 and 2021 with an emphasis on the depopulation processes of the post-Soviet period. The root cause of depopulation is insufficient fertility to replace generations over a long time. The number of births is determined by the number of female reproductive cohorts and their age structure in addition to the per-woman fertility. The study presents the features of the dynamics of these indicators for childbearing-age women by constituent entities in the context of all-Russian trends. Demographic analysis of dynamic series distinguishing the populations of urban and rural areas has been used as a research method, with its information base being Rosstat data for 1980-2021. It is shown that the number of women of reproductive age, especially in rural areas, was decreasing faster than the total population of Russia. At the same time, nationwide, the number of women in the most fertile age groups of 20 to 34 years declined even more rapidly. The sharpest negative trends in the sizes of the considered cohorts were manifested in the Far Eastern Federal District, which has long been experiencing an outflow of migrants. In addition to the reduction in the total number of women aged 15-49 in Russia, their age structure also changed: the number and proportion of young women decreased in both the cities and in the countryside, while women of older reproductive ages with much lower fertility rates, on the contrary, became more prevalent. A particularly strong decline in numbers due to extremely low fertility in the 1990s was recorded in the most reproductively active age group of 25 to 29 years. As a result of such quantitative and qualitative changes associated with the long-term decline and aging of women of reproductive age, the country’s prospects of exiting lingering depopulation by increasing the number of births are severely complicated. This complexity is even greater given the dramatic increase in the number of deaths from 2020 due to the spread of coronavirus. Thus, the natural population decline in 2021, record-breaking for the entire post-Soviet period, reinforces an extremely negative trend towards further depopulation in Russia and its regions with the corresponding consequences for the future of the country, its socio-economic development, geopolitical status, and national security. The results of the study may be useful for the legislative and executive authorities when shaping and adjusting demographic policy and socio-economic development strategies.

The article deals with the social and economic factors of migrations by rail across Russia. It uncovers the main reasons for human migration in the regions from and to which citizens change their place of residence. The aim of the research is to determine the factors influencing the migration flows in the spatial relationship between regions, considering the density of railroad infrastructure. The objectives are to study and identify statistically significant indicators that characterize relocation factors. For the study, we use statistical data on migration in 78 regions with the presence of rail transport and address population resettlement across the country (interregional gain/loss, thous. ppl.). Interregional migration flows are being studied more extensively each year due to their increasing relevance, which results from changes in the overall composition of the population, and the loss of citizens caused by the shifting geopolitical situation. The article notes the authors dealing with the issues of resettlement and exploring population mobility patterns by different socio-economic influences involving regional transport. We analyze factors of influence on resettlement with the least squares method. Several indicators are determined as statistically significant, while "outliers", i.e., data reflecting factors without impact on population flows, are preliminarily excluded. As a result, the article gives a cartographic representation of internal human migration. Visualizing the results of the study on regional resettlement by railroads makes it possible to identify significant migration factors that affect transport routing. The data obtained in the study of migration flows can be used by transport companies to inform decisions in planning regional development across the Russian Federation.

The article deals with the relationship between value-added and household consumption indicators under the input-output model. It studies the problems of developing and using regional intersectoral models with an extended set of endogenous parameters. The practical applications of disaggregated regional models based on the Social Accounting Matrix method are shown to be limited. The Miyazawa model serves as a tool to analyze intersectoral interactions in the region’s economy, linking the indicators of formation and use of income by various groups of households. The additional features of the considered model are revealed in comparison with the classical input-output model. We describe the production and consumption effects of multiplication from the consumer activity of households. The article also analyzes intersectoral relations in the regional economy based on data for the Republic of Buryatia for 14 types of economic activity. We present the wage and specific expenditure coefficient matrices for final household consumption in the context of 5 income groups by sectors of the economy in the republic. A comparative analysis of the region’s gross output multipliers by Leontiev and Miyazawa models has been carried out. It is determined that the consumer activity of households has a maximum impact on the “education” and “health and social services” economic activities. The minimum influence is inherent in “construction” and “wholesale and retail trade”. In conclusion, we prove that applying the Miyazawa model at the regional level provides greater adequacy compared to the calculations at the national scale due to less dependence on the final use of profits.

The article considers the Altai regions located practically in the center of the Eurasian continent, peripheral to Kazakhstan, China, Mongolia, and Russia with mainly agro-industrial development. We identify functional features and potential growth opportunities for individual Greater Altai regions in the framework of their cross-border location and international cooperation, specifically within the Chinese Belt and Road Initiative. The initiative provides for new areas of cooperation largely in improving the connectivity of regions, creating new transport and logistics chains. There is a high mineral potential in Greater Altai, which is now poorly developed, except for the large deposits at the Rudny Altai (Kazakhstan and southwest Altai Krai). Joint development of mineral resources can provide a synergistic effect on how all Altai regions evolve, significantly changing their economic position in the global goods and services markets. The potential of recreational resources is also of significant interest in terms of arranging international historical, cultural, ecological, cognitive, and extreme tours around the “Golden Ring of Altai" covering all the region’s countries. Construction of new highways in Western Mongolia and Xinjiang Uyghur Autonomous Region, expansion and reconstruction of roads in Russia and Kazakhstan will increase the recreational potential of these countries, boost their internal and interregional communication connectivity, create favorable conditions for intraregional trade, and establish modern market and tourism infrastructure.

The article sums up the results of the II International Conference on Eurasian Cross-Border Economic, Scientific and Technological Interactions (Novosibirsk, December 12-14, 2022). It reviews its goals, objectives, and main plenary reports. It is concluded that the Conference was held at a high academic level with excellent organization and received wide publicity. By analyzing the presentations, speeches, and discussions, we study the following: a changing configuration of cross-border interactions between Eurasian countries, international scientific and technical cooperation in view of the global challenges and threats arising in 2022; the positioning of Siberia and its regions in the system of trans-Eurasian integration under new conditions; the role of Russian science in implementing the new state policy of international economic, scientific, and technical cooperation; and opportunities for enhancing interacademic cooperation with Russia. It is Siberia that is currently becoming the most important Russian macro-region, capable of implementing a new configuration of Eurasian economic, scientific, and technological interactions. At the same time, the new Siberia’s role in the system of Eurasian integration should be based on a modernized economic development model, focused on a greater part for innovation and knowledge. We point out the vast capabilities of the Novosibirsk science and innovation ecosystem, which is truly growing into a crucial Russian science and innovation hub for eastern and southern cross-border interactions.