Publishing House SB RAS:

Publishing House SB RAS:

Address of the Publishing House SB RAS:
Morskoy pr. 2, 630090 Novosibirsk, Russia

Advanced Search

Atmospheric and Oceanic Optics

2021 year, number 2

Spatial structure of femtosecond laser radiation during filamentation in air

D.V. Apeximov, Yu.E. Geints, A.A. Zemlyanov, A.N. Iglakova, A.M. Kabanov, O.I. Kuchinskaya, G.G. Matvienko, O.V. Minina, V.K. Oshlakov, A.V. Petrov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: femtosecond laser pulse, air, filamentation, light channels, diffraction-ray tube

Abstract >>
The results of experimental and theoretical studies of the evolution of the small-scale transverse structure of high-power femtosecond laser radiation propagating in air in the multiple filamentation mode are presented. It has been found that the presence of intensity inhomogeneities in the initial transverse profile of a laser beam leads to the formation of high-intensity light channels due to the Kerr-induced self-focusing effect. When the power in these channels exceeds a certain threshold value (the critical power), the filamentation in these structures is implemented. Parameters of these light channels are theoretically estimated on the basis of the diffraction-ray model of single filamentation. It is shown that the initial radius of intensity inhomogeneities in the transverse profile of a laser beam with a centimeter radius and subterawatt power is of characteristic value of several millimeters.

Study of propagation of ultrashort laser pulses in the atmosphere

E.I. Sidorkina, A.G. Svetashev, L.N. Turyshev, N.V. Dorozhko
National Ozone Monitoring Research and Educational Center, Belarusian State University, 7, Kurchatov, Minsk, 220045, Republic of Belarus
Keywords: numerical simulation, ultrashort laser pulses, induced Raman scattering

Abstract >>
The results of numerical simulation of femtosecond laser pulse propagation in main atmospheric gases (N2 and O2) under the effects of coherent Raman scattering are considered. It is shown that when femtosecond 2p-pulses propagate through a gaseous medium, SRS regime is implementable, under which energy losses are insignificant.

Foreign-continuum absorption in the wings of the IR H2O bands

O.B. Rodimova, T.E. Klimeshina
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: water vapor continuum, water-nitrogen continuum absorption, spectral line wings, second virial coefficient

Abstract >>
The H2O foreign-continuum absorption in the IR region is regarded according to the asymptotic line wing theory presenting absorption as a sum of the individual line absorption coefficients with a special line shape at far distances from the line center. The line shape parameters pertaining to quantum and classical 2-N2 interaction potentials are found as a result of fitting the experimental absorption data in the 4200-5000 cm-1 spectral interval and the data on the temperature dependence of the second virial coefficient. This line shape is used for calculation of the continuum absorption in the 1000-10000 cm-1 region.

Retrieval of the spatial distribution of the average air density in a supersonic jet from laser transillumination results

D.A. Marakasov, V.A. Banakh, A.A. Sukharev
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: supersonic jet, laser transillumination, wavefront distortions, air density, retrieval

Abstract >>
The problem of retrieval of the spatial distribution of the average air density in a supersonic jet from the results of laser transillumination is discussed. It is shown that for axially symmetric flows, the retrieval can be carried out on the basis of the Abel transforms from measurements of local wavefront tilts. An algorithm for retrieving the average density from the transilluminating wavefront deviations transverse to the jet axis has been developed and tested in experiments at the Vertical Jet Device of ITAM SB RAS. The results are in a good agreement with both the data of contact measurements known from the literature and the results of numerical solution of the hydrodynamic problem.

Influence of the atmospheric transport of suspended particles PM10 on the optical characteristics of the Black Sea surface layer

D.V. Kalinskaya, O.B. Kudinov
Marine Hydrophysical Institute National Academy of the RAS, Sevastopol, Russia
Keywords: atmosphere, aerosol, microparticles, concentration, MODIS, AERONET, HYSPLIT, CALIPSO, PM, PM, MPC

Abstract >>
The event of the autumn transport of PM10 from the east to the Black Sea water area and coastal zone is studied. Optical characteristics of the suspended particles are analyzed based on field and satellite data. A correlation is shown between the variability of optical characteristics of PM10 and an increase in the fluorescence intensity of dissolved organic matter in the sea surface layer, measured at the northeastern coast of the Black Sea from the Professor Vodyanitsky research vessel.

Distribution of heavy metals in dust aerosol and soils of northern Tajikistan

M.N. Rakhmatov1, S.F. Abdulaev2
1Khujand State University named after academician Bobojon Gafurov, Khujand, Republik of Tajikistan
2S.U. Umarov Physical-Technical Institute of Academy of Sciences of Rebublic of Tajikistan, Dushanbe, Tajikistan
Keywords: aerosol, elemental composition, soils, heavy metals, arsenic, pollution sources

Abstract >>
The concentrations of heavy metals (or metal oxides) and arsenic in samples of atmospheric aerosol and soil collected in northern Tajikistan in 2011 to 2019 are determined. Their local sources, mainly anthropogenic (automobile transport, metallurgical enterprises, open tailing dumps, etc.) are discussed. Possible sources of air transport of pollutants to the territory of the Sogd region are identified on the basis of the HYSPLIT back trajectory model

Granulometric composition of settled aerosol substance and ratio of phenolic compounds in needles of different age

M.P. Tentukov1,2, V.I. Michailov3, D.A. Timushev4, D.V. Simonenkov2, B.D. Belan2
1Pitirim Sorokin Syktyvkar state University, Syktyvkar, Komi Republic, Russia
2V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
3Institute of Chemistry of the Komi Science Centre of the Ural Division RAS, Syktyvkar, Komi Republic, Russia
4Physics and Mathematics Institute of the Komi Science Centre of the Ural Division of the Russian Academy of Sciences, Syktyvkar, Komi Republic, Russia
Keywords: laser granulometry, efflorescence, submicron aerosols, secondary organic aerosols, phenolic compounds, needles contamination

Abstract >>
Results of laser granulometry of nanodispersed fraction of aerosol substance and UV spectrometry of water washes of different-age needles of four plant species are given. Influence of hydrothermal conditions on temporal variability of morphometric parameters of needles and contamination of its surface by phenolic compounds in composition of secondary organic aerosols is evaluated. A mechanism for generating secondary organic aerosols on the surface of different-age needles during efflorescence of phenolic compounds and their subsequent entry into the forest canopy during turbulent separation of the boundary layer from the sheet surface is discussed.

Heat fluxes in the surface air layer with decomposition of initial components onto different scales

V.A. Gladkikh1, I.V. Nevzorova1, S.L. Odintsov1,2
1V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
2National Research Tomsk State University, Tomsk, Russia
Keywords: atmosphere, heat flux, surface layer, gray zone, turbulence

Abstract >>
The paper discusses the results of calculation of heat fluxes (kinematic temperature fluxes) in the surface air layer from experimental data on variations in the air temperature and wind vector components on different scales. The fluxes along three coordinate axes of the stationary and accompanying Cartesian coordinate systems are compared. Estimates of the heat fluxes for the territory with natural landscape (at two altitudes in the surface layer) and the urban territory are considered. The analysis of experimental data has led us to the conclusion that the heat fluxes on the local scale should be taken into account along with the heat fluxes on the turbulent scale when predicting the state of the atmosphere using models of high spatial resolution.

Long-term seasonal changes in atmospheric circulation over Siberia in the late XX - early XXI centuries

N.V. Podnebesnykh
Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: season, Siberia, cyclones, anticyclones, number, average pressure at the center, duration of baric formations

Abstract >>
The variability of the characteristics of cyclones and anticyclones (number, pressure at the center (hPa), and duration (days)) and their trajectories is studied for Siberia (50-70 N, 60-110 E) in different seasons throughout the climatically significant time interval 1976-2018 on the basis of surface synoptic maps. It is found that the number of baric formations has increased, the pressure at the centers of cyclones has decreased and at the centers of anticyclones increased, and the duration of cyclones and anticyclones has decreased during the period under study. These trends in the behavior of the characteristics of cyclones and anticyclones are especially pronounced at the end of the period. During the year, the anticyclonic weather was observed more often than cyclonic in Siberia.

Hypothesis about differences in starting conditions for transient luminous events of the middle atmosphere

E.A. Sosnin1,2, V.S. Kuznetsov1, V.A. Panarin1, V.S. Skakun1, V.F. Tarasenko1,2
1High Current Electronics Institute of the Siberian Branch of the RAS, Tomsk, Russia
2National Research Tomsk State University, Tomsk, Russia
Keywords: apokampic discharge, plasma bullet, transient luminous events (TLEs)

Abstract >>
The propagation velocity of plasma plumes in the presence of an external electric field was measured in air, at a pressure corresponding to the altitudes of the middle atmosphere transient luminous events. Based on the results, a hypothesis is formulated that the transient type starting from the thundercloud dome (blue jet, starter, gigantic jet) depends on the intensity of intracloud lightings and the ratio of the positive charge of the dome top and the negative charge of the outer layer.

Rainfall measurements during summer 2020 with the optical rain gauge

V.V. Kalchikhin, A.A. Kobzev, A.A. Tikhomirov, D.E. Filatov
Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: precipitation, measuring, optical precipitation gauge

Abstract >>
Results of measurements of the amount of precipitation with an OPTIOS optical precipitation gauge together with a standard Tretyakov O-1 gauge during three summer months of 2020 are presented; a good agreement between the measurement results is shown. The comparison of the OPTIOS readings with the readings of a similar optical rain gauge mounted at a distance of 3 km, as well as with related data of the Tomsk weather station of the Roshydromet network located at a distance of 6 km, shows significant spatial variations in the characteristics of atmospheric precipitation. A possibility of using OPTIOS both as an automated gauge within a weather station and as a component of an observation precipitation gauge network is shown.