Home – Home – Jornals – Atmospheric and Oceanic Optics 2023 number 1

A highly accurate and detailed expert list of absorption lines of the ³²SO₂ molecule in the range 0-4200 cm^-1 has been created. The line centers in the expert list are determined from the experimental and calculated by the effective Hamiltonian energy levels, and the intensities are mainly variational data. The list contains 549200 vibrational-rotational transitions for 22 bands. The obtained centers and line intensities are compared in detail with the HITRAN2016 database and the AMES empirical list. Comparison with experimental data also shows that the accuracy of the variational calculation of the intensities of the spectral lines of the ³²SO₂ molecule depends on the vibrational quantum numbers.

The paper is dedicated to the memory of V.I. Tatarsky (1929-2020); however, it is not personalia. We present, as a brief review of our scientific works, the experimental and theoretical proofs of the E. Hopf's conjecture (1948) about the structure of turbulence as a space-time chaos of a finite number of interacting coherent structures. This review is the result of our many years research in the theory of turbulence. The theory of turbulence is a scientific direction that the authors have chosen under the scientific influence of V.I. Tatarsky.

The paper presents a tool for numerical simulation of the backscatter enhancement effect associated with double-pass propagation of laser radiation passing through an anisotropic non-Kolmogorov turbulence. It is shown that for variety of power-law exponents of refractive-index fluctuations, all other conditions being equal, the value of the enhancement factor also changes: it increases when the fluctuation spectrum becomes more and more low-frequency. For the anisotropic medium, the two-dimensional distribution of the enhancement factor allows remotely determining the spatial orientation of anisotropic inhomogeneities in a randomly inhomogeneous medium.

We propose and analyze a new method for total ozone columns (TOC) retrieving by interpreting satellite-measurements of outgoing thermal radiation of the Earth (spectrometer IKFS-2, Russian satellite "Meteor-M" N 2). The new method is based on an inverse operator which is constructed using ground-based standard observations of TOC (Dobson and Brewer spectrophotometers) and satellite measurements together with multilinear regression. The method is analyzed using standard ground-based TOC measured by Dobson at Voeikovo station, Leningrad region (Voeikov Main Geophysical Observatory). The analysis shows that multilinear regression between TOC from ground-based measurements and spectra of outgoing Earth radiation by satellite observations approximates TOC in Voeikovo for 2015-2020 with an error of 2.8% and a correlation coefficient (CC) of 0.97. TOC time series retrieved from the inverse problem by the regression method has an error of 3.1% and a CC of 0.97. The method suggested can be implemented in different Earth regions with satellite observations and TOC retrieved from ozone measurements at World Meteorological Organization (WMO) stations.

Results of measurements of the NO₂ contents in the vertical columns of the troposphere and stratosphere with the TROPOMI (Tropospheric Monitoring Instrument) aboard the Copernicus Sentinel-5P satellite in 2018-2020 are compared with the results of ground-based measurements at the Zvenigorod Scientific Station (ZSS) of the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences. The comparison of the satellite data with the ZSS data is carried out for the two products of satellite measurements: the NO₂ contents in the tropospheric and stratospheric columns. The correspondence between the results of satellite and ground-based measurements is characterized by the difference between them, linear correlation coefficients, and regression coefficients. The dependences of the comparison characteristics on the season, cloud conditions, and the height of the atmospheric boundary layer are revealed.

Results of experimental determination of the laser radiation extinction index by the gradient method from the depth profiles of the airborne polarization lidar return signal power for clear and coastal sea water in the subsurface layer are presented. Based on synchronous measurements of the polarized and depolarized signal components with the “Makrel” lidar operating at a wavelength of 532 nm, laser radiation extinction coefficients were estimated. It has been experimentally demonstrated that the polarized and depolarized lidar return signal components have different seawater extinction indices, and the difference can reach several ten percent. The depth profiles of the laser radiation extinction indices retrieved from these signal components for two series of lidar measurements are given. Such an integrated approach expands the possibilities of remote hydrooptical sensing.

The results of the analysis of changes in the quality of atmospheric air in the city of Ufa from 2017 to 2020 are presented. The influence of meteorological factors on the level of pollution in the city of Ufa is considered. The basis for the analysis are instrumental measurements at nine Roshydromet stations. The daily values of the atmospheric pollution parameter are calculated. Trends in the level of atmospheric pollution by various impurities are determined. Using the method of wavelet transformation, the characteristic periods in the variations in the level of pollution are ascertained. Using the cross-wavelet analysis, links between air pollution and dangerous meteorological parameters are revealed. It is found that the average concentrations of sulfur dioxide, xylenes, and toluene increased in 2017-2020; high level of atmospheric pollution is observed in the calm weather, light winds, and temperature inversions. The observed changes in urban air pollution provide unique grounds for experimental assessment of the impact of various anthropogenic factors on the qualitative composition of atmospheric air.

Based on ERA 5 reanalysis data and average daily surface ozone concentrations (O₃) measured at the TOR station from 1993 to 2020, the circulation mode, which contributes to the formation of extremely high ozone concentrations (95th percentile, further О₃95), is studied. It is found that for all months; an identical circulation mode is distinguished, characterized by an increase in surface air temperature in the area, which includes the TOR station. In addition to the increase in air temperature, О₃95 events are characterized by an increase in the southwestern component of wind speed. It was also found that these circulation features are associated with the development of meridionality, probably due to the propagation of waves in midlatitudes. The revealed circulation mode simultaneously contributes to the transboundary transfer of ozone and its precursors from the southern regions, the enhancement of ozone photochemistry, and the emergence of an additional source of ozone precursors - wildfires.

The polarization elements of the light scattering matrix in the vicinity of the backscattering direction of a perfect hexagonal column and a particle of a random convex polyhedral shape are studied within the physical optics approximation. The study was carried out for particles with a size of 10-100 microns for a wavelength of 0.532 microns. It is shown that, within the vicinity of the coherent backscattering peak, the polarization elements of the matrix have significant local extrema. At the same time, their angular width practically does not depend on the shape of the particle, but significantly depends on the size. The results are of interest for the interpretation of lidar measurements in cirrus clouds.

The paper presents the results of the experimental study of the dynamic characteristics of the laser fragmentation/laser-induced fluorescence (LF/LIF) process in nitrobenzene and para -nitrotoluene vapors under synchronized two-pulse laser irradiation. It is shown that if the values of the time delay between the pulses of fragmentation (248.4 nm) and excitation (247.87 nm) of NO-fragments are in the range 20-40 ns, the efficiency of the LF/LIF method can be increased by several times.