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

2020 year, number 1

Collisional broadening of vibrational-rotational CO2 lines by buffer gases

K.I. Arshinov1, O.N. Krapivnaya1, V.V. Nevdakh2, V.N. Shut1
1Institute of Technical Acoustics, Academy of Sciences of Belarus, Vitebsk, Belarus
2Belarusian National Technical University, Belarus, 220013, Minsk, ul. Ya. Kolasa, 13
Keywords: ненасыщенный коэффициент поглощения, относительный коэффициент ударного уширения, буферный газ, unsaturated absorption coefficient, relative collisional broadening coefficient, buffer gas

Abstract >>
Unsaturated absorption coefficients in pure CO2 and binary mixtures of CO2 with buffer gases M j (He, Ar, Kr, Xe, N2, O2, CO, N2O, 13C16O2) were measured at the central frequencies of the R (8), R (22), R (34), P (8), P (22), and P (36) CO2 spectral lines of the 1000-0001 transition at 300-700 K with a tunable CO2 laser. A technique is described and the coefficients of self-broadening and broadening of CO2 spectral lines by a buffer gas M j are calculated. It is shown that the efficiency of CO2 interaction with diatomic and triatomic molecules is determined by the electric moment; in the case of inert gases, the mass factor plays the major role. It is ascertained that the temperature dependences of the collisional broadening of CO2 spectral lines can be highly accurate approximated by power functions with two different exponents.

The effect of collisional line broadening on the accuracy of tropospheric temperature measurements using pure rotational Raman lidars

V.V. Gerasimov1,2
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: комбинационное рассеяние, лидар, уширение спектральных линий, калибровочная функция, температура тропосферы, Raman scattering, lidar, spectral line broadening, calibration function, tropospheric temperature

Abstract >>
The effect of collisional line broadening on the accuracy of tropospheric (0-11 km) temperature retrievals from pure rotational Raman lidar raw signals is estimated via numerical simulation. The simulation was performed for three sets of spectral filters with different passbands in a lidar receiving system. A narrow-linewidth laser with a wavelength of 532 nm was considered as a lidar transmitter. A comparative analysis of temperature retrieval errors (calibration errors) produced by using nine calibration functions is presented. The calibration function retrieving tropospheric temperature with the least errors is determined for each set of filters.

Optimization of wave detuning during effective second harmonic generation

V.O. Troitskii
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: генерация второй гармоники, высокая плотность мощности лазерного излучения, численные методы, оптимизация волновой расстройки, second harmonic generation, high density of laser radiation power, numerical methods, optimization of wave detuning

Abstract >>
Second harmonic generation (SHG) in a nonlinear uniaxial crystal is theoretically studied. The main attention is paid to the estimation of the wave detuning effect on the SHG efficiency. The results presented confirm a strong dependence of the optimal value of wave detuning on the laser radiation power and a way of its focusing in a nonlinear crystal. A quite rapid algorithm is suggested for the numerical solution of the wave detuning optimization problem. The applicability of this algorithm to the analysis of highly efficient SHG is shown, including situations where the nonlinear conversion efficiency attains its maximum.

Turbulence intensity estimation from lidar data

I.A. Razenkov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: атмосферная турбулентность, увеличение обратного рассеяния, лидар, atmospheric turbulence, backscatter enhancement effect, lidar

Abstract >>
A method for estimating the intensity of the structural characteristic of the fluctuations of the refractive index Cn2 from the data of a two-channel turbulent aerosol lidar operating on the effect of backscattering enhancement (BSE) is shown. It is proposed to use the Vorob'ev approximation, which for the case of homogeneous turbulence determines the dependence of Cn2 on the ratio of echoes. The basis for this was experimental data, from which it follows that the BSE effect occurs in a relatively small area of space near the scattering volume. The results of sounding along a horizontal path are presented.

Studies of the possibility of determining vertical refraction by the turbulent method

D.V. Dementiev1,2
1Group of Companies LLC "Geodesy and Construction", Moscow, Russia
2Moscow State University of Geodesy and Cartography, Moscow, Russia
Keywords: рефракция, турбулентные методы, флуктуации угла прихода, искажения световой волны, температурная стратификация атмосферы, refraction, turbulent methods, arrival angle fluctuations, light wave distortions, temperature stratification of the atmosphere

Abstract >>
At present, only one classical technique accounting refraction during periods of undisturbed images allows one to largely compensate the influence of refraction on the results of geodetic measurements. However, these periods are very short, and their limits are extremely difficult to estimate. Therefore, despite many years of effort, the problem of accounting for refraction in geodetic measurements has not received a satisfactory practical solution. According to the studies of the turbulent method, the accuracy of the refraction determination corresponds to the instrumental accuracy of the device used, even in conditions of unstable temperature stratification of the atmosphere, when significant fluctuations of the angle of arrival are observed.

Variability of sunlight duration in Tomsk in 1961-2018

T.K. Sklyadneva, B.D. Belan
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: атмосфера, продолжительность, радиация, регрессия, солнечное сияние, atmosphere, duration, radiation, regression, sunlight

Abstract >>
Variations in the sunlight duration (SLD) in Tomsk are analyzed for the period from 1961 to 2018 and separately for 1961-1990 and 1981-2010. Data on clouds and total solar radiation obtained at the TOR-station of IAO SB RAS in 1996-2018 are used. The actual long-term monthly mean SLD ranges from 44 hours in December to 317 hours in June-July. The analysis of the long-term variation in SLD shows its increase from 1961 to 1989 and its decrease starting from 1999 caused by an increase in the lower cloud amount and high frequency of continuous clouds. SLD in Tomsk in the modern period has increased relative to the historical period. Regression equations between SLD and the total solar radiation ( Q ) are derived.

Dynamics of the Antarctic polar vortex during the 2002 sudden stratospheric warming

E.S. Savelieva
Institute of Monitoring of Climatic and Ecological Systems of the Siberian Branch of the Russian Academy of Sciences, Tomsk, Russia
Keywords: внезапное стратосферное потепление, антарктический полярный вихрь, нижняя субтропическая стратосфера, sudden stratospheric warming, Antarctic polar vortex, lower subtropical stratosphere

Abstract >>
In September 2002, the sudden stratospheric warming (SSW) was observed over the Antarctic as a result of the polar vortex splitting. The unusually early breakdown of the Antarctic polar vortex in spring 2002 was caused by the increased activity of vertically propagating planetary waves. The dynamics of the south polar vortex during SSW of 2002 is investigated. An unusual temperature decrease in the lower subtropical stratosphere, which contributed to a decrease in the stratospheric meridional temperature gradient is considered a possible cause of the weakening of the polar vortex, which preceded its splitting under the influence of planetary waves.

Seasonal and long-term variability of the zonally averaged fields of TOC

G.M. Kruchenitsky1,2, K.A. Statnikov2
1Central Aerological Observatory, Moscow Region, Russia
2Moscow Institute of Physics and Technology (State University), Moscow Region, Russia
Keywords: озон, сезонная и долговременная изменчивость, тренды, приливные колебания, параметрический резонанс, ozone, seasonal and long-term variability, trends, tidal fluctuations, parametric resonance

Abstract >>
Zonal averaged fields of seasonal and long-term variability of the total ozone content (TOC), including polar regions, are investigated. It is shown that the long-term variability of all these series (with a spatial resolution of 3° latitude) is reduced to a parametric resonance with the lowest of the tidal oscillation frequencies (period of 18.6 years). After excluding this effect, series trends for all latitudinal zones become vanishingly small (having different signs) and statistically insignificant. The results are completely incompatible with the anthropogenic version of ozone depletion. It is stated that the phenomenon of parametric resonance is also observed in the lithosphere as applied to global tectonic activity.

Atmospheric black carbon and surface albedo in the Russian Arctic in spring

A.A. Vinogradova1, T.B. Titkova2
1A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, Moscow, Russia
2Institute of Geography RAS, Moscow, Russia
Keywords: Арктика, климат, атмосфера, черный углерод, альбедо поверхности, метеопараметры, множественная линейная регрессия, Arctic, climate, atmosphere, black carbon, surface albedo, meteorological parameters, multiple linear regression

Abstract >>
We are studying the statistical relationships between the atmospheric column black carbon (BC) and the surface albedo ( A ) based on MERRA-2 reanalysis data for four test areas near the Arctic coast of Russia in April 2010-2016. The analysis also includes atmospheric meteorological parameters from the WATCH website data: air temperature and amounts of liquid and solid precipitation. The statistical analysis has been carried out for daily average values. An increase in the air temperature is accompanied by a decrease in the surface albedo everywhere, both on a monthly scale and in daily variations. Snowfalls increase the surface albedo also everywhere. Reliable negative correlations between BC and A in April were found only on the Gydan Peninsula. Some years (different for different areas) with good correlations between day-to-day variations in A and BC values within a month, also with negative coefficients, were revealed. We estimated possible changes in albedo values, as well as in albedo radiative forcing due to variations in different parameters.

Analysis of brown carbon content and evolution in Siberian biomass burning smoke plumes using AERONET data

N.A. Golovushkin1, I.N. Kuznetsova2, I.B. Konovalov1, M.I. Nahaev2, V.S. Kozlov3, M. Beekmann4
1Institute of Applied Physics of the Russian Academy of Sciences (IAP RAS), Nizhny Novgorod, Russia
2Hydrometeorological Centre of Russia, Moscow, Russia
3V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
4Laboratoire Interuniversitaire des SystГЁmes AtmosphГ©riques, France
Keywords: дымовой аэрозоль, коричневый углерод, сибирские пожары, AERONET, biomass burning aerosol, brown carbon, Siberian fires, AERONET

Abstract >>
The content and evolution of brown carbon (BrC) in biomass burning smokes from Siberian forest fires were analyzed using measurements of the absorption aerosol optical thickness at three AERONET stations situated in Tomsk (in Siberia), Zvenigorod (near Moscow), and Yekaterinburg (at the Ural). The analysis resulted in estimates of the relative contribution of BrC in fine aerosol particles to the absorption of solar radiation at a wavelength of 440 nm (hBrC), in particular, for an anomalous episode of the long-range transport of biomass burning smoke from Siberia into the European part of Russia in summer 2016. A considerable fraction of BrC is found in smoke aerosol over Tomsk and Zvenigorod (where hBrC is estimated to be about 15 and 18% on average), while the estimates of hBrC for Yekaterinburg are found to be insignificant. The analysis also revealed a decrease in hBrC in the process of aerosol aging under the illuminated conditions on the time scale of about 30 h. At the same time, the measurements in Zvenigorod indicate an increase in the absorption properties of the organic fraction of biomass burning aerosol after much longer atmospheric evolution.

Winter background aerosol deposition in the south-eastern part of Western Siberia

Yu.V. Ermolov, N.B. Smolentsev
Institute of Soil Science and Agrochemistry of the Siberian Branch of the Russian Academy of Science, Novosibirsk, Russia
Keywords: снеговой покров, примеси снега, аэрозоль, фоновое поступление, юго-восток Западной Сибири, snow, sedimentation of air impurities, aerosol background, Western Siberia

Abstract >>
We show that snow from the ice surface of lakes in oligotrophic bogs is suitable for monitoring the deposition of "long-distant" aerosol. Based on the concentration of impurities in snow samples from the plains of Baraba and Vasyugan, we estimated the background of winter deposition of aerosol substances in southeast of Western Siberia. It was found that the deposition of aerosol particles per day is about 7 mg/m2, including 3.1 mg/m2 in the form of solid particles. Winter deposition of particulate matter does not exceed 10% of annual deposition; therefore, it has almost no effect on sedimentation. The mineral substance prevails in solid impurities of snow, the average ash content is 65%. The background mineralization of snow water from the ice surface of oligotrophic bog lakes in the southeast of Western Siberia is close to the global background of precipitation mineralization.