Home – Home – Jornals – Atmospheric and Oceanic Optics 2018 number 6

The measurements of CIMEL CE 318 sun photometer near Saint Petersburg within the International monitoring AERONET network are analysed. Typical regional aerosol optical characteristics (aerosol optical depth, Angstrom exponent, and single scattered albedo) and their variations are determined. Some regularities in variations in the aerosol parameters over the North-West region of the Russian Federation are revealed. The study is supplemented by the joint analysis of data from the nearby AERONET observation sites in Finland and Estonia, satellite measurements, and MERRA reanalysis data.

The variability of time series of the integral moisture content of the atmosphere and the surface partial pressure of water vapor for the territory of Europe over a long period have been studied. The main contribution to variance of moisture contents is given by seasonal variations; it is 60-70%. Mesoscale processes give 7-17%; synoptic processes give 17-27%. The linear trend contributes less than 1% to the overall variance of the variability of the atmospheric moisture content in Europe. It is shown that the interannual variability of the atmospheric moisture content is manifested both in the quasiperiodic variability of the annual mean values and in the variations in the intensity of the synoptic processes. The irregular coherence of variations in the circulation indices and surface partial pressure of water vapor in Europe with periods of 2-3 years, 5-6, 8-11, and 10-13 years is established.

Models of estimation of average and maximum concentrations of chemically active impurities in cross sections of plumes from remote stationary sources are suggested. Approbation of the models is carried out on data of aircraft sounding of multicomponent pollution of the winter atmosphere of the Norilsk industrial region. Process of active transition gas ® particle, observed at a distance of 58-103 km from a source of emissions, is numerically studied. Average and maximum sulfur oxidation rates in the winter polar atmosphere are estimated as 0.027-0.034 h^-1 and 0.055-0.07 h^-1, respectively.

We investigated the main precipitation modes over Mongolia and southern part of Eastern Siberia in midsummer. We used precipitation data from GPCC archive (1979-2013). The EOF analysis was applied to the interannual change in July precipitation for two areas: “big” (90-120°E; 35-70°N) and “small” (the Selenga basin, 96-110°E; 46-54°N). The total amount of precipitation within the Selenga basin in July was calculated. According to the obtained estimates two leading EOFs (EOF1 + EOF2) explains 32.3 and 48.9% of the total variance for the big and small areas, respectively.

Using the monitoring data of electrical quantities of a surface layer in Tomsk in 2006-2017, the their slow variations connected with passage of cumulonimbus ( Cb ) clouds and concomitant weather phenomena in the warm and cold seasons were studied. In total, 453 and 210 events for warm and cold seasons, respectively, were considered. A statistical analysis of these slow variations in the electric field potential gradient was carried out. The distribution of the total duration of the potential gradient slow variations is described by the power-series distribution (Pareto distribution).

The performance of a direct variational data assimilation algorithm with quasi-independent data assimilation at individual steps of the splitting scheme was evaluated in the realistic scenario of the air pollution assessment in the city of Novosibirsk. An algorithm with minimization of the spatial derivative of the uncertainty (control) function, which is adjusted to assimilate data, was considered in the case of sparse monitoring network. The use of the spatial derivative minimization allowed increasing smoothness of the uncertainty (control functions) reconstructed, which has a positive effect on the reconstruction quality in the scenario considered.

The work is devoted to numerical simulation of the hydraulic regime of the Lena River delta based on the system of Saint-Venant equations. This system describes the unsteady motion of the river flow in one-dimensional approximation. The numerical solution of Saint-Venant differential equations is based on the use of an absolutely stable implicit difference scheme and a specially developed method of Gaussian elimination for a “tree” graph of branched and looped sections of the river network. The calculated water discharge distribution over the main branches of Lena River delta and the comparison between modeling runoff at the Olenekskaya hydrometric cross sections with the field data in 2005 are presented.

Hydrochemical studies were carried out on the territory of oil-production enterprises of the Tomsk region located in the floodplain of the Ob and Vasyugan rivers. It was found out that oil products whose concentration exceeds the MPC value by 3-5 times are rated as the largest contributors to the pollution of rivers flowing through the territories of oil fields. The contents of chlorides, sulfates, calcium, salts of heavy metals, and magnesium exceeds the maximum permissible levels by several tens of times. The most dangerous for human health aromatic compounds were identified among oil pollutants, including pyrenes, fluoranthenes, chrysenes, benzanthracenes, which constitute a group of carcinogens. The main impact on water quality is exerted by surface runoff from the oil-polluted territory of the river watershed. For the spring period of 2014 the volume of oil products removed to the network of the Ob river was 3.2 tons on the territory of the Sovetskoye oil field, while the annual runoff was 4.9 tons. Geochemical data could be successfully used for mapping oil spill using GIS technologies and planning preventive measures for localization and restoration of contaminated sites in areas of oil and gas producing complexes.

A modified beam-splitting algorithm for solving the problem of light scattering on atmospheric concave ice crystals being typical for cirrus clouds is developed. It is based on the beam-splitting algorithm for convex crystals that was created at Institute of Atmospheric Optics SB RAS. The algorithm is used for the solution of the light scattering problem for hollow-column particles and hexagonal column aggregates. The algorithm is on open access with open source code.

The adsorption and photosorption properties of plasmatronic ZnO particles under ambient air are investigated. The composition analysis of surface layer adsorbed on microparticles is carried out. The kinetics of desorption and adsorption processes on microparticle surfaces under darkness and illumination are studied. The quantum yield and spectral dependency of quantum yield of NO photoadsorption are determined.

A four-channel photoelectric counter has been worked out and manufactured for the measurements of saltating sand concentration fluctuations and size distribution function of particles with diameters > 30 mm over desertified areas. The measurement results are given. It is shown that the vertical profile of the saltating sand concentration does not change on average in the altitude range from 3 to 7 cm over a desertified area in the neighbourhood of Volga. The distribution function of saltating sand particles over the desertified area is approximated with satisfactory precision by the lognormal distribution near the distribution maximum. Noticeable distinctions between above mentioned distributions for large and small sand particles are observed.

The technique and results of an experimental study of the disperse composition of a liquid-drop aerosol in the nozzle spray cone are presented. To determine the particle size in the spray cone using the method of measuring the small-angle scattering phase function a new experimental setup was used. The parametric analysis is carried out. The criterion relations for the maximum diameter of the particles in the spray of the centrifugal nozzle are presented. It is shown that the particle size spectrum in the spray cone corresponds to the gamma distribution.

Dynamics of layer-by-layer variability of aerosol contamination of snow cover in circulating conditions in winter period at the experimental site of the "Fonovaja" observatory (Institute of Atmospheric Optics of SB RAS) in the Tom-Ob interfluve 60 km west of Tomsk is analyzed. The chemical composition of the snow cover at the point of observation is characterized. It is established that in the elemental composition of the aerosol substance accumulated in the snow layer, a typomorphic association of indicator elements associated with coal mining is steadily manifested. The conclusion about the seasonal impact on the aerosol field of the "Fonovaja" observatory of enterprises of the coal-mining complex located to the south of the investigated territory is geochemically substantiated. It has been shown that the detection of remote sources of aerosol contamination of the snow cover is expedient to base on the morphometric analysis of the terrain and a retrospective estimate of the temporal variability of the indicators reflecting the effect of meteorological factors (dispersion ratio of surface aerosol, wind regime, snowfall intensity) and in context of the analysis of the features of the layered distribution of indicator groups of typomorphic elements, characterizing specific types of enterprises, in the snow layer.

Different ways of dispersion of solid-phase particles are considered: pulse, electrostatic, and pneumatic. The model experiment on sedimentation of fine airborne particles of polymeric substance kollidon is made. A change in the concentration of the studied aerosol particles at ultrasonic sedimentation is analysed. The pilot study has shown that electrostatic generation of aerosol considerably increases the speed of sedimentation of particles with application of ultrasound.