Home – Home – Jornals – Atmospheric and Oceanic Optics 2013 number 8

This article provides the results of investigations of aerosol microphysical properties variations in the lower part of the atmosphere in the Primorye coastal area. The analyzed data were obtained during the period from 01.08.2010 till 31.12.2012 at the lidar station of the Institute of Automation and Control Processes FEB RAS. Typical values of mass concentration of submicron aerosols, black carbon and particle size distribution functions were obtained for different seasons. During the winter with strong north winds and low relative humidity values (50 ± 20)% a dry continental aerosol dominates at the region of investigation and numerical aerosol concentration (N_a) has higher values between 100 and 120 cm^–3. During the summertime when south winds dominate and relative humidity reaches values of 98%, N_a has low values of (5 ± 5) in June, 2011 and (44 ± 20) cm^–3 in July, 2011. Diurnal variations of mass and numerical concentrations of atmospheric aerosols and black carbon are well-defined in winter. Modal radius of fine aerosol particles has values of 0.275 mm in summertime and 0.375 mm in wintertime and for the coarse aerosol particles modal radius reaches 1.05 and 2.5 mm in winter and summertime, consequently. The more stable seasonal and diurnal variations were obtained from black carbon mass concentration measurements. Its values vary in the range from (0.5 ± 0.5) at the early summer to (3.0 ± 2.0) mg/m³ in winter. It was shown that diurnal variations of M_BC in Tomsk and Primorye coastal area have the same shape, but in the last case the amplitude of variations is bigger.

A comparative analysis of the characteristics of the aerosol obtained in the Caspian Sea on the RV "Rift" in November 2008 and in October 2012, in the near-water atmospheric layer and throughout the entire thickness of the atmosphere. Under study were: aerosol optical depth (AOD in the wavelength range 0.3–2.14 microns) and the columnar water vapor of the atmosphere, particle number concentration and particle size distribution in the range of 0.3–20 microns in diameter, the mass concentration of submicron aerosol mass concentration and absorbing aerosol – "soot", chemical ionic composition of the soluble part of aerosols and trace gases – Cl^–, SO₄^2–, NO₃^–, РО₄^3–, F^–, HCO₃^–, Na⁺, NH₄⁺, K⁺, Mg²⁺, Ca²⁺, H⁺, HCl, HNO₃, SO₂, NH₃.

Ecological problems of the rocket-space and aviation techniques exploitation are discussed. The mathematical modeling results of the thermogasdynamic processes at the liquid-drop medium polluting the atmosphere at separated stages of the rocket carries falling and at the aviation fuel emergency reset are presented.

The paper presents the results of field survey, chemical-analytical and numerical analysis of data on processes of dust aerosols precipitations in the area of intensive influence Tomsk GRES-2 of emissions in winter periods from 2009 to 2012. In the model reconstruction of the field depositions monodisperse contaminants from a point source we interpret the observed data content in the snow solid residue of uranium, thorium, in the direction of the route of sampling. It is shown that the most significant deposition of contaminants occur near vicinity of tall pipes station comprising larger particle fractions.

The problem of nonlinear propagation of intense femtosecond laser pulses in the near-infrared spectral range in air is theoretically considered. By numerically solving of the paraxial propagation equation for optical wave envelope the dynamics of self-focusing and filamentation of dark hollow light beams having a ring-shaped transverse intensity profile are investigated in the conditions of a wide variation of beam initial angular divergence. We found that the filamentation region of such beams in comparison with the Gaussian beam filamentation of equal power is located much father on the optical path, and posseses a significantly greater longitudinal extent, as well as the density of the free-electron laser plasma. By changing the initial angular divergence or the width of the annular region of initial intensity profile it is possible to effectively control the position and length of the filaments on the propagation path.

Within the density matrix framework, we obtained an expression for the transient third-order susceptibility and relating refractive index induced by stimulated Raman scattering of femtosecond pulse on molecular rotational transitions. It is explicitly shown that the nuclear sub-system response to the pulse field is anisotropic and delayed in time. Calculated average values of the refractive index n₂ for molecular nitrogen (2 × 10^–19 cm²/W) and oxygen (4 × 10^–19 cm²/W) agree with those available in literature.

Results of the analysis of existential variability of total solar radiation in the territory of Western Siberia are presented. It is shown that in the South and the southwest of Western Siberia the tendency of a negative trend of coming solar radiation is noted. In the south of Western Siberia the maximum receipt of total radiation is registered in June–July depending on the year of measurements, and in the north – in July. The minimum variations of the monthly sums of total radiation are observed during the summer period (2–15 of %).

By results of plane sounding the dynamics of vertical distribution of ozone in the atmospheric interface is considered. Measurements were made from the An-2 plane board. During 2011–2012, 6 plane soundings of vertical distribution of ozone were carried out to the characteristic periods of year (winter, spring, summer) in an interface to the atmosphere over Berezorechka post of the Tomsk region. It is shown that during active photochemical generation of ozone in an interface of the atmosphere the noticeable daily course, which is defined by its formation of in situ was observed. Thus, in the period of an active turbulent exchange in the top part of an interface the descending stream at the expense of ozone involvement from the free atmosphere, in its lower part the expressed ascending stream, which is caused by ozone generation from gases of predecessors is observed.

The conditions for obtaining higher detection probability of spatial objects by either panchromatic or multi-spectral detector have been determined using statistically synthesized model of optimal detector.

Aspects are investigated of building the statistical characteristics of random functions for discrete-continuous averaging according to the end-time response of the measurement device. This averaging is typically implemented in practice, and any discrete sequence (empirical values ​​of a random function) is partially averaged sequence (over some interval of the argument). Estimates of the rate of convergence are found of the time-mean to the ensemble-mean (the generalizations of the Taylor ergodic theorem). These estimates provide a convergence in probability. It is shown that the convergence rate depends on the integral correlation scales of the random function. These scales are determined by the type of averaging, they are different for the continuous, discrete, and discrete-continuous averaging. An equation relating the correlation functions of non-averaged and partially-averaged random processes is found. It is found that correlation function of the non-averaged process can be satisfactorily recovered from a partially-averaged data, even at very long intervals of partial averaging.

Based on results of numerical simulation and processing of real satellite data, a method is proposed for automatically estimating the quality of MODIS meteorological data, used for atmospheric correction of satellite IR measurements of land surface temperature.

The description of the complex measurement and computation system for monitoring and forecasting the meteorological situation at the airport is presented. The system consists of the meteorological temperature profiler MTP-5PE, Vaisala Weather Transmitter WXT520, main and remote control terminals, network data storage, two high-resolution meteorological models, server, and SKIF Cyberia complex at Tomsk State University. The paper presents the results of the measurements and forecasts of the atmospheric temperature profile and surface values of the wind velocity and direction, pressure, humidity and temperature of the previous winter, characterized by various extreme weather events observed at the airport Bogashevo. It is shown that the measured and calculated temperature profiles for the lower part of the atmospheric boundary layer have a good qualitative and quantitative agreement of the results.

Errors in lidar measurements of the air density in the middle atmosphere are analyzed. A lidar was placed onboard the ISS. A solid-state Nd:YAG-laser, operating at the 3rd and 4th harmonics with wavelengths of 355 and 266 nm, was used as a lidar transmitter. Calculations were performed for the lidar with reasonable parameters: pulse energy of 0.4 (355 nm) and 0.2 J (266 nm), pulse repetition frequency of 20 Hz, accumulation time of 60 s, radius of the receiving mirrors of 0.3 and 0.5 m, field of view of the receiving telescope of 1 and 0.1 mrad, filter bandwidth of 0.5, 1, and 10 nm, and spatial resolution of 1 km. The results showed that radiation at a wavelength of 355 nm can cover altitude range, on average, from 75 km at night and from 55 km in the daytime to 10 km depending on the parameters of the lidar with 10% measurement errors (calculations were not carried out below 10 km). When operating with radiation at 266 nm for 10% measurement error, the sensing range can be expanded to the upper mesosphere at 90 km and penetrate deeper into the atmosphere to 38 km. Thus, the use of two harmonics allows the altitude range of air density measurements from the ISS to be expanded from 90 km down to the troposphere.

The results of photo-acoustic measurements of the laser pulses with a wavelength of 266 nm by water vapor mixed with nitrogen on laser radiation intensity are presented. The laser radiation intensity varies from 0.5 till 10 mW/cm² and water vapor partial pressure changes with 0–10 mbar. It is shown that with laser intensity increase the absorption is linear for H₂O partial pressure increase from 0 to 5 mbar and becomes ruther stable at H₂O partial pressure increase from 5 till 10 mbar.