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Model estimates of the altitude of the mixing layer in the atmospheric boundary layer under conditions of temperature inversions are compared with the experimentally estimated altitude of the layer of intense turbulent heat exchange. The experimental data are received with the temperature-wind system consisting of meteorological acoustic lidar (sodar), meteorological temperature profilometer, and ultrasonic anemometers-thermometers. It is shown that under conditions of temperature inversions, the altitude of the mixing layer calculated by the model equations is usually much smaller than the altitude of the layer of turbulent heat exchange.

Ozone is one of the most toxic impurities in the troposphere. Therefore, it is recognized as the number one pollutant in most countries and its concentration is monitored. This work presents an overview of continuous measurements of the ozone content in the troposphere over Russia throughout 2021 carried out on an initiative basis at 16 stations in different Russian regions. The monitoring results showed that the daily mean ozone concentration exceeded the MPC_dm at all observation sites during a significant part of the year. Two- and even three-fold excess over MPC_dm was observed at a number of stations. At six stations, concentrations above the MPC_s were recorded. This requires a more comprehensive analysis of the composition and concentration of ozone precursors and the development of measures to reduce their emission into the atmosphere.

A global analysis of geographical features of vertical profiles of specific humidity and concentrations of sulfur dioxide and sulfate aerosols from the CAMS reanalysis data, as well as height of planetary boundary layer (PBL) from the ERA5 reanalysis data for 2003-2020 is carried out. The scale height H_Y is used as a characteristic of the mentioned profiles, which corresponds to the e -fold decrease in the substance Y concentration. The maxima of the height of the upper boundary of the planetary boundary layer are noted in the regions of prevailing cyclonic circulation - in storm tracks and in the regions of monsoon circulation in summer. For the vertical scale of the specific humidity profile, minima are identified in the regions of subtropical circulation with prevailing large-scale sinking of air. The vertical scale of the SO₂ concentration profile is characterized by spatial minima associated with the oxidation of this substance. Finally, for H_SO4 a spatial minimum near Southeast Asia is found. A statistically significant negative correlation between the PBL thickness and the vertical scale of the profile of specific humidity in humid regions of the tropics is revealed. A positive correlation between the vertical scales of the concentrations of sulfur dioxide and sulfates, most significantly manifested in the regions of strong pollution of the lower troposphere by these substances, is also obtained.

Optical resonance of the internal field of a dielectric microparticle occurs when the frequency of the incident light is tuned to the frequency of one of the particle spatial eigenmodes which leads to a sharp increase in optical intensity and higher field localization near the particle rim providing the formation of annularly-periodic structures in the form of standing waves, the so-called “whispering gallery” modes (WGM). We theoretically consider the case where a dielectric microsphere is placed near a flexible light reflecting membrane, which acts as an external pressure sensor. In this case, due to reflection from the reflecting membrane, the WGMs of the sphere are excited twice by direct and reflected backward radiation, which then couples within the microparticle volume. The optical intensity of the resulting WGM carries enough information about the position of the flexible loaded membrane. This allows one to propose a physical concept of a new miniature all-optical pressure sensor. We show that the pressure sensitivity of such a sensor depends on the quality factor of the excited resonant mode, as well as the geometrical and mechanical parameters of the flexible membrane. Important advantages of the sensor proposed are the miniature design (the size of the sensor is determined by the diameter of the flexible membrane) and the non-contact type of the pressure sensor placement.

Fine and nanosize particles of both natural and anthropogenic origin can be present in the atmospheric air and affect the environment and human health. The effect of inhalation the cobalt ferrite CoFe₂O₄, magnetite Fe₃O₄, and tin dioxide SnO₂ nanopowders on the carbon dioxide content in air samples taken from the noses of laboratory animals is studied. The CO₂ concentration is determined from the absorption spectra of air samples recorded with a laser photoacoustic (PA) gas analyzer. It is ascertained that inhalation of magnetite nanoparticles leads to a decrease in the concentration of carbon dioxide in the samples of exhaled air of laboratory animals, which can indicate a negative effect of such exposure.

The effect of impurity gases (benzene and toluene) on measurements of the mercury concentration in natural gas is estimated. The measurements were carried out with analyzers with mercury capillary lamps (MCL) as a radiation source. The MCLs were placed in the magnetic field to produce the longitudinal or transverse Zeeman effects. It is shown that in the transverse Zeeman effect, when the triplet of p-, s⁺-, and s^--components is emitted, the effect of impurity gases on the measurement results of mercury concentration in natural gas several time decreases. The minimum allowable concentration of benzene and toluene (up to 10 mg/m³) in natural gas is experimentally determined, which does not affect the measurement of mercury concentration with an analyzer with a MCL filled with mercury of natural isotopic composition in the transverse Zeeman effect.

The author describes the specifics of the multi-scale mathematical modeling of geomedium as a case-study of a two-scale model. The first scale modeling assumes the linearly elastic medium, and the second scale model includes the plastic strains and internal friction. It is shown that in the first approximation, when the micro-level stress gradients are assumed to be constant, the model acquires elastoplasticity with regard to local bends of structural elements of the geomedium. The solution of the problem on plane S-waves reveals that the waves possess dispersion and their velocity decreases with increasing plastic strains.

The authors develop the DEM-based procedure for the numerical testing of granular samples under non-uniform compression with different load programs. The algorithm of initial packings of particles is proposed. The calculations are performed for different methods of loading with suppressed dilatancy and with dilatancy-generated volume. The macro characteristics of the stress-strain behavior of the test samples are related with the micro properties of discrete particles. The post-critical shearing induces the unstable behavior with localizations of shears, and a descending branch appears in the load diagram. The application ranges of the developed method for the mathematical modeling of shear localization are defined.

The author proposes an eco-friendly method for the remote evaluation of productivity of hydrocarbon reservoirs using records of the natural seismicity background of the Earth. The evaluation uses the thermodynamic indicator of rock mass quality based on the Klimontovich entropy. The latter is a correct measure of disequilibrium of open systems and can be measured from the ratio of chaotic character and orderliness of vibrations generated by the system. The thermodynamic indicator obeys the linear dependence on the total thickness of productive beds in boreholes. The big natural and induced noise may distort the distance evaluation. The new algorithm is high-amplitude noise resistant. The thermodynamic indicator ensures productivity mapping of hydrocarbon reservoirs and enables selecting the most promising drilling sites.

The failure mechanism and acoustic emission are studied in uniaxial loading tests of coal-rock samples at three values of coal/rock ratios. The scope of the analysis includes the stress-time curve, compressive strength, elastic modulus, acoustic emission events and energy counts. The failure characteristics, deformation and acoustic emission of the compound body are analyzed.