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The perturbation theory is applied to calculation of the vibrational energy levels of isotopically substituted molecules. Within the Born-Oppenheimer approximation, the isotopic shifts of energy levels are represented in the form of power series of small parameters, i.e., the relative change in the masses of substituted atoms. The coefficients of the series are functions of the molecular constants of only one modification of the isotopic family of a molecule. This makes it possible, having determined these coefficients either from calculation or on the basis of a semi-empirical approach from experimental data, to calculate isotopic shifts for any isotopologues, including short-lived ones. As an example, the isotopic shifts of the levels of unstable water isotopologues Н₂^ХО, Х = 13-15 and 19-24, with a half-life of more than 1 ms are calculated. The levels calculated are compared with the results of variational calculations with a high-precision function of the intramolecular potential energy.

Absorption spectrum of water vapor highly enriched with ¹⁷O (more than 80%) was recorded using a Bruker IFS 125M Fourier spectrometer in the 7900-9500 cm^-1 range at room temperature. The spectrum was recorded at a pressure of about 24 mbar with a spectral resolution of 0.02 cm^-1. About 6300 lines with a minimal intensity value of 5.0 × 10^-27 cm/molecule are found in the recorded spectrum. 4835 recorded lines are assigned to 5185 transitions of five water isotopologues (H₂¹⁶O, H₂¹⁷O, H₂¹⁸O, HD¹⁶O, and HD¹⁷O). H₂¹⁷O lines are assigned to 14 vibration bands. Most of them are the lines of the ν₂ + 2ν₃, 3ν₂ + ν₃, ν₁ + ν₂ + ν₃, ν₁ + 3ν₂, and 2ν₁ + ν₂ bands. The lines of the ν₁ + 2ν₂ + ν₃ - ν₂, 2ν₁ + ν₃ - ν₂, and 2ν₁ + 2ν₂ - ν₂ hot bands are assigned for the first time. The assigned lines allow us to determine 153 new vibration-rotation energies of nine vibrational states of the H₂¹⁷O molecule and 22 energies of two states of the HD¹⁷O molecule. The data obtained are compared with the results of previous studies, the HITRAN2020 spectroscopic database, and W2020 list.

Using numerical finite-difference time-domain (FDTD) calculations, we simulate and examine the absorption dynamics of the near-infrared optical radiation in a spherical microcapsule surrounded by solid nanoparticles of different optical properties (metal, biocompatible dielectric). A model microcapsule resembles a microcontainer used in modern bio- and medical technologies for targeted delivery of therapeutic nanodoses of drugs to the desired region of the biological tissues. We show that due to light scattering on nanoparticles, the optical field superlocalization in the "hot regions" on the microcapsule surface take place. The three-fold light absorption enhancement can be achieved due to the addition of buffer nanoparticles.

Ground-based MW spectrometers play an important role in the O₃ regional monitoring. They measure the downward thermal radiation in various ozone absorption lines. Using numerical simulation, the information content of typical ground-based measurements of downward MW thermal radiation in the ozone absorption line at 110.836 GHz, the errors in the ozone vertical profiles at altitudes of 20-60 km, and the influence on them of a priori information about the solution and type of the inverse operator used in the regression method for solution of the inverse problem are studied.

Methods for estimating the buoyancy and rise characteristics of atmospheric pollutant emissions from high sources are discussed. They are based on the application of the relations of the theory of similarity and dimension for smoke plumes. Aerological sounding data and satellite images of plumes and their shadows on the earth's surface are used as additional information. The proposed approach to assessiment of the buoyancy flows of smoke plumes and the height of their rise was tested for three large thermal power plants in Siberia. A satisfactory agreement between the results and the normative characteristics of buoyancy flow for the chimneys under consideration has been established.

The paper considers changes in the state of the environment in Krasnoyarsk and its environs during the existence of the smoke of large-scale Yakut fires in August 2021. The appearance of smoke aerosols in the atmosphere led to a weakening of the passage of solar radiation to the Earth's surface and, accordingly, to a decrease in the temperature of the active soil layer and the surface air layer. Advection of cooled air with high relative humidity over the surface of the Yenisei River in the lower reaches of the Krasnoyarsk HPP formed cooling mists.

The outcome of the first tests of a measuring system designed for the monitoring of atmospheric aerosol content and meteorological parameters is considered. Based on the measurement results from August 2022, the data of the system prototypes, a calibrated optical aerosol sensor, and the on-site meteorological station are compared. The revealed drawbacks of the system design are described. The plans to improve and extend the system capabilities are discussed. A blueprint of a future multipoint aerosol monitoring network in Yekaterinburg and its neighborhood is presented.

The ecological state of the Arctic hydrocarbon deposit territories over the period 2013-2022 is estimated. Vegetation cover is considered an indicator of the ecological state of the territories under study. Based on the Terra/MODIS satellite data, the state of the vegetation cover of hydrocarbon fields in the Purovsky district of the Yamal-Nenets Autonomous Okrug is studied: Urengoyskoye, Vostochno-Tarkosalinskoye, Gubkinskoye, Vyngayakhinskoye, Komsomolskoye, and Tarasovskoye. Using the ArcGis geographic information system, the average values of EVI (Enhanced Vegetation Index) of the field vegetation cover for the full growing season from May 25 to September 20, 2013-2022, are calculated. The EVI minima and maxima for the territories are determined. Tendencies towards an increase in EVI in the final growing season over the 10-year period under study are found.

A time-varying flow velocity method for a conceptual model of river flow generation is implemented with the aim of improving flow routing in the Lena river basin. In contrast to constant velocity models, this approach uses a time-varying velocity which depends on the amount of flow generated in a land grid cell. The Manning equation is used to estimate flow velocity in the rectangular cross-sectional approximation for the river channel. Numerical experiments with constant and variable flow velocities made it possible to compare the model flow with the observed daily hydrographs at the runoff stations of Kyusyur, Tabaga, and Verkhoyanskiy Perevoz. The work provides an estimate of the heat flow from the Lena river basin to Kyusyur gauging station for 2002-2011.

An approach which combines remote and ground-based methods for monitoring oil-contaminated soil and vegetation cover is suggested. A map is presented that reflects the natural and anthropogenic structure of the territory of the Nefteyugansk region of the Khanty-Mansiysk Autonomous Okrug in the conditions of oil and gas production. The legend of the map shows 10 natural and 3 anthropogenic types of vegetation cover and the open surface of the Earth in the area located in the Salym-Ob flat terraced swamp-taiga landscape province. It was revealed that after oil spills, the soil and vegetation cover experiences a long-term negative impact. The NDVI values in the oil-contaminated areas are 0.1-0.3 lower than in the background ones. In satellite imagery in days close to those of ground-based surveys, the NDVI of oil-contaminated areas of sedge-sphagnum bogs is 0.45 (8.08.2020) and 0.42 (23.08.2021), respectively. In small-leaved and light-coniferous forests on sites with a negative impact of fresh oil spills, NDVI = 0.32 (25.09.2020) and 0.42 (23.08.2021), respectively. The concentration of oil products in contaminated soil samples lies in the range 280-580 g/kg, exceeding the approximately permissible concentrations by 70-145 times.