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The comparative analysis of data available from open sources on the water spectral lines intensities in the frequency range from 0 to 1.75 THz has been carried out. The calculations by the method of effective Hamiltonians and the variational method, as well as experimental data were taken into account. It has been established that the intensity uncertainty is less than 2% for lines in the ground vibrational state with an intensity of more than 10^-27 cm/mol. and is about 5-10% for weaker lines. For strong (more than 10^-26 cm/mol.) lines in the ν₂ state, the uncertainty ranges from 2 to 5% and increases to 5-10% for weak lines. For all lines in the 2ν₂, ν₁, and ν₃ states, the uncertainty is no more than 5-10%. The presented data show that most of the considered lines can be assigned a higher (by 1-2 steps according to the classification adopted in HITRAN) category of intensity accuracy.

The form of the vibrational-rotational operator of kinetic energy for linear symmetric molecules of the A₂B₂ type in polyspherical non-orthogonal internal (bond lengths and angles between bonds) coordinates is obtained. Non-orthogonal coordinates have advantages in calculating the wave functions of heavy linear molecules, for example, C₂F₂, C₂Cl_2, and also simplify the calculation of the intensity of the lines of the vibrational-rotational spectra of molecules of this type. This work is a continuation of the previous work [1], in which the form of the kinetic energy operator in orthogonal coordinates was obtained. To verify the obtained expressions, the lower vibrational-rotational energy levels of the acetylene molecule were calculated.

Graphical resources on the continuum absorption of water vapor and its mixtures published in 2011-2020 are described. Summary tables are presented that characterize the main parameters of the absorption coefficients and transmission functions in different spectral intervals, the temperature dependence of the absorption coefficient, and the equilibrium constant of the water dimer formation reaction. The features of the study of the continuum absorption in published works in this time interval are noted. In a concise form, the results of the assessment of the quality of citing plots are presented, which are described by four qualitative and quantitative attributes. Three citation procedures are characterized, two of which are computerized. A method for estimating the difference between the citing and cited plots and examples of pairs "citing and cited plots" with a quantitative assessment of the difference are presented.

This work is a continuation of the paper "Measurements of atmospheric parameters along an extended paths. I. Acoustic measurements of turbulence and average wind speed" and is devoted to the results of optical measurements of atmospheric turbulence along horizontal atmospheric paths. These measurements were carried out to determine the effective mean values of atmospheric turbulence parameters along an optical radiation propagation path and the associated coherence length of optical waves propagating through the atmosphere. The path optical measurements were supported by AMK-03 acoustic weather station measurements. That made it possible to compare the local acoustic and optical measurements of turbulence with different optical meters.

The results of experimental studies of aerosol in the surface air layer in the southeastern part of the Crimean Peninsula at the background environmental monitoring station of the Vyazemsky Karadag scientific station from March 21 to June 17, 2020, are presented. The daily average mass concentration over aerosol for the entire measurement period ranged from 3 to 35 mg/m3, with an average value of 13 mg/m3. The exception was high concentrations of particles during the episode of 25–27.03.2020 (48, 195, and 49 mg/m3), when a extreme eastward transfer from sources in Kazakhstan (a dust storm on the Aral Sea) through Kalmykia to the Crimea took place. Taking into account this episode, the daily average aerosol mass concentration was 16 mg/m3. Days with different directions of air masses arrival, as well as days with the highest daily mean values of aerosol mass concentration were identified out of 89 observation days. For this sample (31 samples), the content of 64 chemical elements was determined in the samples. Accumulation of chemical elements in soil and in aerosol particles was estimated; clarks of chemical element concentrations in soil, aerosol concentration coefficients, and enrichment coefficients of chemical elements in aerosols were calculated. The dependences of the mass concentration and disperse and elemental composition of the surface aerosol on further aerosol migration are considered.

Water vapour plays a key role in different climate-forming processes at various altitudes of the Earth's atmosphere. Water vapour isotopologues monitoring provides information on the atmospheric hydrological cycle. It helps to study the processes associated with evaporation and condensation that control the humidity in the troposphere and water exchange between the troposphere and stratosphere. For the first time, temporal variability of water vapor isotopologues (H₂O and δD) in Peterhof in 2009-2020 were analyzed using ground-based measurements of solar IR radiation by the Bruker IFS 125HR Fourier spectrometer. For both H₂O and δD, the maximum values occur in summer, the minimum - in winter, while the largest variability of H₂O is observed in summer, and δD - in winter months due to the climatic features of St. Petersburg, i.e. the origin and history of incoming air masses. The database of water vapour isotopic composition in the vicinity of St. Petersburg can be used in models of the general circulation of the atmosphere to improve the accuracy of weather forecasting and long-term changes in the regional climate.

The results are presented of laboratory experiments to determine the characteristics of convective turbulence over a heated metal surface for various heights and temperatures by high-speed thermography. The study of convective turbulence characteristics was carried out using a high-speed infrared camera by shooting the temperature field of low-inertia paper targets suspended above the heated surface simultaneously over the entire vertical plane of the IR camera field of view. Based on fluctuations in the temperature field of the target surface, the heat transfer coefficient, the intensity level of the convective flow, the total flow, and the amount of heat generated during measurements at different heights above the surface are determined. The energy spectra of convective turbulence are plotted under various turbulent conditions. An analysis of the turbulence spectra showed the presence of an inertial interval with a slope close to the 8/3 power law for all considered heights above the heated surface, temperatures, and turbulence conditions. Characteristics of convective turbulence obtained can be used when testing various optical adaptive laser beam control systems, studying the propagation of vortex laser beams and combustion centers, which are also characterized by convective turbulence with a further transition to atmospheric turbulence induced by combustion energy.

This paper reports on the hydrogeological conditions and groundwater regime in the Lena River floodplain near Yakutsk. The published and archive materials, including field data collected by the authors in 2013-2021, were analyzed. Data from more than 70 boreholes were examined to characterize permafrost and hydrogeological conditions in the area. Data on groundwater level monitoring in the reclaimed area of the floodplain were also used. Over 250 sample analyses were interpreted to characterize the chemical composition of surface and ground waters. The results suggest that suprapermafrost waters in the high floodplain are recharged both by infiltration of river water and by a transit water flow under the river channel hydraulically connected to floodplain taliks. The seasonal and spatial variability of the chemical composition of waters was revealed in the Lena River and in the studied taliks. The surface and ground waters of the Quaternary aquifer on the east bank of the Lena River are characterized by the lowest total dissolved solids (TDS) concentration (0.1-0.3 mg/L) and by the magnesium-calcium chloride-bicarbonate composition. These waters are recharged by fresh water of the supra- and interpermafrost taliks of the Bestyakh terrace and by the riverbed taliks under small rivers. In the vicinity of Yakutsk, TDS concentrations in the Lena River and in the Quaternary aquifer increase to 0.5-1.3 g/L due to high mobility of chloride and sulfate ions migrating with the surface and suprapermafrost runoff from the low terrace, where the city is located.

High rates of degradation of the Bolshoy Azau Glacier on Elbrus make it necessary to assess the development of lakes on the ice-free land and on the glacier itself. For this purpose, aerospace data for the period of 1957-2021, as well as information from visual observations, Internet sources, and tourist photographs were analyzed. The existence of 15 lakes with an area of 0.14-20.25 thousand m² on the Bolshoy Azau Glacier and the adjacent territory was recorded at various times. The long-term existence of the lake in contact with the glacier on the Echo of the War mountain passage covering with an area of up to 4.5 thousand m² was revealed for the period of 1971-2009. The maximum area (20.25 thousand m²) was detected on a satellite image from June 25, 2009 for a lake on the dead ice part of the median moraine between left and right ice streams of the Bolshoy Azau Glacier. In the hollows on the glacier surface, up to three lakes with a maximum total area of 7.86 thousand m² were observed in different times. Lakes on the Bolshoy Azau Glacier appeared mainly during the snow cover melting, while masses of drifted snow served as dams in the drainage area of hollows. These lakes disappeared after melting of drifted snow dams and/or in the course of drainage through subglacial and underground runoff channels.

The probabilistic-statistical method is applied to study the causes of the thermokarst distribution heterogeneity along the long linear constructions. A list of natural conditions affecting the development of thermokarst along an oil pipeline is discussed. The methodology for zoning buffer area of long-distance linear constructions (e.g., oil pipeline) according to the conditions of thermokarst development is substantiated. We have delineated thermokarst-susceptible and thermokarst-tolerant areas along the oil pipeline buffer zone according to the environmental conditions.