Home – Home – Jornals – Advanced Search

The paper presents the results of calculating 10 the lowest vibrational energy levels of all 24 stable sulfur dioxide isotopologues. The calculations were performed using the ab initio potential energy function of the main isotopologue ³²S¹⁶O₂, the Rayleigh-Schrödinger perturbation theory of high orders and the Padé-Hermite series summation method. A numerical analysis of the series was performed, which showed that the perturbation series monotonically converge, but to obtain the energy levels of some vibrational states with an error of less than 1.0 cm^-1, it is necessary to take into account the corrections of the 3rd-6th orders. The quadratic Padé-Hermite approximants give energy levels that coincide with high accuracy with the results of numerical diagonalization of the Hamiltonian matrix. A correction is proposed for calculating isotopic shifts, which gives a root-mean-square coincidence of 1.1 cm^-1 with the experimental and calculated data by other authors. The calculation results can be used to solve various problems of atmospheric spectroscopy, astrophysics, geochemistry, and other fields of science related to the analysis of spectra of isotope-substituted molecules.

Based on a developed and adapted method for identifying Rossby wave breaking (RWB), which accounts for the specifics of stratospheric circulation, an analysis of the conditions for the occurrence of major sudden stratospheric warmings (SSWs) in the Northern Hemisphere was conducted. The method relies on examining the geometry of potential vorticity contours in the stratosphere at the 850 K level using ERA5 reanalysis data. It is shown that anomalous RWB processes in November and December play a key role in preparing for the onset of SSWs. Most of the analyzed SSW events are associated with an increase in the number of RWB events in the Asia-Pacific (AP) region in November and December, and occasionally in January. In cases where SSW initiation is linked to RWB over the Atlantic and Europe, it is also preceded by RWB anomalies in the AP region. For the identified types of wave breaking in the stratosphere, atmospheric blocking is characteristic in the troposphere, accompanied by negative near-surface temperature anomalies over Eurasia and/or North America. The increased frequency of early and middle major SSW events aligns with the previously identified trend of enhanced negative temperature responses to atmospheric blocking in the Northern Hemisphere.

The development of the deep underwater neutrino telescope BAIKAL-GVD involves the creation of equipment for regular long-term monitoring of inherent optical properties (IOP) of the aquatic environment within the effective volume of the telescope. Regular monitoring of IOP not only allows increasing the accuracy of retrieving neutrino energy and direction, but also provides unique data for limnological studies. The article describes the design of the BAIKAL-5D devices developed to solve this problem and considers the methods and algorithms for in situ monitoring of IOP used in these devices. The sources of instrumental error in measuring the absorption and scattering of light in water are investigated and the necessary corrections are determined. Some results of measuring IOP of the deep waters of Lake Baikal using BAIKAL-5D devices are presented.

This paper demonstrates for the first time the possibility of exciting anti-Stokes fluorescence of PO-fragments of organophosphates. Using the example of drop-liquid traces of triethyl phosphate on a paper surface, it was determined that the relative population of vibrational levels v '' = 1 and v '' = 2 corresponds to a vibrational temperature of fragments of about 780 K. Indicators of significant violation of the equilibrium distribution of fragments over rotational energy levels were revealed. It has been determined that the method of exciting anti-Stokes fluorescence of PO-fragments of triethyl phosphate from the first vibrational level of the ground state X ²Π ( v '' = 1) to the zero vibrational level of the electronically excited state A ²Σ⁺ ( v ' = 0) provides the highest noise immunity of the LF/LIF method. The results can be used to select the optimal technique for exciting fluorescence of PO-fragments when implementing the LF/LIF method for remote detection of organophosphate traces.

The paper is devoted to research of the output signal composition of metal-vapor laser active optical systems under various operating conditions. The effect of the temporal characteristics of laser active optical systems on the output signal composition is experimentally estimated. The method for determining the contribution of amplified spontaneous emission (ASE) to the output signal of self-adjoint scheme and scheme with independent illumination source is suggested. The optimal time when input signal enters to active medium of amplifier for providing maximal signal/noise ratio is determined. ASE is completely suppressed at a time delay of (-4.3; +25.8) ns in the scheme with independent illumination source. It is impossible to achieve complete suppression for the self-adjoint scheme. The minimal ASE value in the self-adjoint scheme was 80 mW, i.e., approximately 2% of the output signal power. The results can be useful in researching the amplification characteristics of active optical systems based on metal vapors, as well as in visual-optical diagnostics in laser monitor circuits on their basis.

This paper considers the problem of classifying cloud images, which are complex texture structures with heterogeneous characteristics. Traditional image analysis methods do not always adequately classify such images, and modern deep learning methods require large amount of data and computational resources. The research focuses on evaluating the feasibility of developing a hybrid method combining traditional statistical approaches to texture description and state-of-the-art deep learning techniques. It was hypothesised that the high-level features extracted by a neural network during training can be insufficiently sensitive to subtle local differences in cloud formations. The hybrid approach was implemented and analysed; low-level texture features were extracted from the images before being analysed by the neural network. However, the test results showed that this technique did not improve the classification quality and turned out to be less effective in terms of accuracy compared to the use of unprocessed images. The results of this work can be of interest to specialists in of Earth remote sensing data analysis, meteorology, and development of new texture image analysis methods.

Experimental data obtained in the surface air layer at two observation sites with the underlying surface different in structure are used to estimate the Monin-Obukhov (MO) scale for different types of temperature stratification. The MO scale (its sign, first of all) is compared with the current temperature profile in the surface air layer. It is shown that the sign of the MO scale not always corresponds to the actual temperature stratification.

Carbon dioxide (CO₂) is one of the main greenhouse gases; the study of its effect on the atmosphere on global and regional scales is of current importance. The development of technical means for remote gas analysis of the atmosphere is associated with the development of new and modernization of existing lidar sensing technologies. The paper presents the results of the development of a 2-μm pulsed differential absorption lidar system for sensing CO₂ along horizontal paths in the atmosphere. The configuration and design of the lidar components are shown. Technical characteristics of the lidar system are provided. The results of lidar measurements of the time variation in CO₂ concentration within the city of Tomsk in winter along a selected sensing path using a topographic target (forest belt) are presented. CO₂ concentrations in the range of 435.2-445.1 ppm, corresponding to the background state of the atmosphere, were retrieved from recorded lidar signals. To confirm the correctness of the lidar data, the CO₂ concentration was synchronously measured using a mobile gas analyzer. Analysis of the results shows that the error of lidar measurements of the CO₂ concentration is 1.3%. The results of the work can be useful in the design, manufacture, and modernization of pulsed IR lidar systems for remote sensing of CO₂ and other atmospheric gases.

In recent decades, an information boom has arisen around the concept of “biodiversity” in the “whirlpool” of environmental aspects and problems. A negative consequence of its wide popularity has been the vagueness of the semantic content and the shapelessness of the construction of the beloved concept. This has complicated the mutual understanding of specialists in scientific and everyday ecology. Clarifications of the definition of the concept of “biodiversity” and the scope of its use, structuring and connection of its object of interest with evolutionary theory are urgently needed. For this purpose, an ordered system of four structural categories of biodiversity is proposed, embodying the evolutionary potential of the population-species, biocenotic, biogeocenotic and biosphere levels of life organization. The categories of biodiversity are designated by symbols: alpha, beta, gamma, sigma biodiversity. Their emergence and long-term existence are due not only to the complex configuration of ranges that arose due to the capabilities of the biota, but, to a greater extent, to the structural features of the abiotic matrix of the external environment. First of all, modern runoff-water-collecting continental-oceanic and relict basins that have lost their former connection with the World Ocean are important. Such megahabitats, clearly delimited from each other by orographic, hydrological, climatic barriers, contribute to isolation and provide biota with the opportunity to freely choose a set of environmental conditions. However, not all biological species can use them, but only those with a suitable set of preadaptations, capable of getting along with each other and stereotypically reproducing a standard set of biota over a long period of time. Attention is focused on biogeocenoses and their catenary compositions - grandbiomes, confined to heliozones of latitudinal extension and their derivatives - climatic, soil, landscape zones. Biogeocenoses and grandbiomes, as elements of gamma-biodiversity, unlike the previous categories, have the ability to involve in their contact not only living but also inert matter, guaranteeing the transformation of an uncomfortable weathering crust into a comfortable living environment, regulated by the biota at its own discretion. Each evolutionarily subsequent category of biodiversity did not destroy or suppress the previous ones, but mutually incorporated them into its structure. Such a construction resembles a series of nesting dolls, which multiplies the stability of the biodiversity system and its potential, guaranteeing a long-term prolongation of life in time and ubiquity in space of the earth’s surface.

The specifics of Norilsk industrial district (NID) soils are abnormally high natural concentrations of heavy metals (HM), in particular Ni and Cu. In such conditions, the additional intake of pollutants into soils with high acidity reduces the stability of soil microflora, and increases the risks of vegetation death. In previous decades, the negative impact of dust and aerosol emissions from industrial enterprises of the NID containing SO2, Ni and Cu on the state of soils and the accumulation of HM in vegetation was revealed. The purpose of this study is to assess the current state of soils and vegetation within the impact zones of enterprises of the NID of various types and to identify the degree of their influence. Using the example of three environmental transects, the impact of prolonged aerosol dust and single contact chemical pollution, as well as mechanical transformation in the construction area of industrial facilities, is estimated. The effect of dust and aerosol pollution was recorded on all transects, two of which showed the highest values of the degree of anthropogenic transformation of vegetation (0.5-1). The most negative impact is observed in areas where contact chemical contamination is superimposed on dust and aerosol pollution. The factor of contact chemical impact, in addition to changing the substantial composition and properties, leads to a change in soil profiles. The factor of mechanical transformation has a noticeable effect on both the composition of phytocenoses and the soil profile. At the same time, the content of HM in this transect does not exceed the values corresponding to the geochemical background. The restoration of vegetation and soils in such areas begins immediately after the ending of mechanical action.