The progress in the technology of generation of high-power femtosecond pulses opens new possibilities for solving urgent problems in atmospheric optics. High energy density and wide spectral range of femtosecond pulses in air increase significantly the information content of laser sensing. The capabilities of spectroscopic methods harnessing the phenomena of light emission and nonlinear and incoherent light scattering also extend. Secondary effects, in particular, the occurrence of a stable supercontinuum of direct white light allows its use as a white-light lidar in remote analysis of optical and microphysical properties of the atmospheric aerosol. Based on the experience of solving inverse problems of laser sensing at the institute of Atmospheric Optics, the refine the methodology of solving this class of problems with the use of promising white-light lidars. As the first necessary stage, the results of numerical experiments on multifrequency aerosol sensing in the visible and near-IR wavelength ranges along vertical sensing path are discussed in the present report. The problem of optimal selection of a wavelength range in solved, the stability of the available reconstruction algorithms under conditions of noise background are investigated for the case wide-aperture signal reception, and the limiting sensing regimes are evaluated.

The He-broadened spectra of carbon dioxide are calculated within the pressure range 2-800 atm in the absorption regions of the bands v₂, v₃, and 3v₃ that are positioned from 590 to 7020 cm^-1. The main difficulty is consideration of the line shape narrowing at relatively high pressures. For Q-branches, this effect is observed at atmospheric conditions and, therefore, it is important for remote sounding of the gas atmosphere. The mixtures of the mentioned gases are well studied in experiments and it can serve as a good test for validating the simulating techniques developing. The line by line method is used with modeling of the single line shape without the conventional interference of lines. The problem is focused on the order and disorder in arrangement of the rotational lines with P-, R-, and Q-branches of vibrational bands. A database CDSD-1000 in the HITRAN format is reformatted with adding supplement four parameters for every entry. The physical meaning of the phenomena known as the line and branch mixing is discussed.

Theoretically the influence of the nuclear vibrations of the N₂ and O₂ molecules on the polarizability of the molecular complexes (N₂)₂ and (O₂)₂ has been investigated. The polarizability calculations of the dimers were carried out within the framework of the DID model in which the molecules, forming the dimer, are represented as anisotropic effective atoms, and their polarizability coincides with the polarizability of the molecules. Within the framework of the model coinsidered the (N₂)₂ and (O₂)₂ dimer polarizability functions have been obtained. For some their configurations the first derivatives of polarizability with respect to the internuclear distances have been calculated.

The semiempirical method for calculation of the dipole moment functions for NO and CO molecules as a piecewise-continuous ones has been developed. The dipole moment functions found exhibit physically correct asymptotic behaviour at small and large internuclear separations and agree with the dipole moment functions near the nuclear equilibrium position of the molecule. In the framework of the approach the multipole and exhange interactions have been considered to improve the dipole moment function under large internuclear distances including the range of small overlapping of the electronic shells for the interacting atoms.

The semiempirical method for calculation of the polarizability functions for diatomic homonuclear molecules as piecewise-continuous ones has been developed. The polarizability functions found exhibit physically correct asymptotic behaviour at small and large internuclear separations and agree with the polarizability functions near the nuclear equilibrium position of the molecule. In the framework of the approach the exchange interactions have been considered to improve the polarizability functions under large internuclear distances including the range of small overlapping of the electronic shells of the interacting atoms. The method has been applied to calculate the polarizability functions of the N₂ and O₂ molecules in the internuclear distances Rε[0,∞).

The high resolution absorption spectra of H₂S have been recorded in the region 7200-7890 cm^-1 with the McMath Fourier transform spectrometer located at Kitt Peak National Observatory. A careful analysis of the spectra led to derivation of 1080 precise energy levels for the 1st decade interacting states of H₂³²S, H₂³³S, and H₂³⁴S isotope species. The energy levels were introduced into a least squares fit using a Hamiltonian which takes into account Coriolis, Darling-Dennison and Fermi-resonance interactions. Precise rotational and coupling parameters have been determined which reproduce the experimental energy levels with 0.0015 cm^-1 for the main isotope species. The experimental band origin E_v=7419.9162 cm^-1 for the super weak (220)-(000) band was obtained for the first time from the simultaneous analysis of cold (220)-(000) and hot (220)-(010) bands. Detailed and accurate H₂S absorption line list was generated in the HITRAN format for the first decade spectral region.

Presented results of testing a developing equipment DAN-2, allowing remote define gas components in atmosphere with the big degree noiseproof factor [1,2]. Determined condition of applicability of method lying in the base of functioning (working) an equipment, on tilted atmospheric routes a length before 3 km and more in the different for dioxide nitrogen. Experimental shown that under tilted corners of flexing, forming (0-10)° from the surface of the Land it is necessary to enter an additional calibring factors, connected with the solar spectrum transformation in atmosphere. Adjustments of other sort, stipulated by corner effects, it is necessary to take account into corners from 0° before 20° at orientation to optical axis of receiving telescope toward the solar disk. Determined factors for different visibility and meteoconditions: cloud, mist, fair weather. Given concrete recommendations on using an equipment DAN-2 for correct interpreting the results of measurements. For length of time from november 2002 on a may 2003 on the base of apparatus complex DAN-2 was received near 400 experimental studies. As a source of atmospheric contamination was choose industrial object, residing in the most center of city Tomsk electric power station GRES-2. Measurements were conducted at a different time of with different types of the atmospheric condition (fair weather, obscured cloud, hazes and mists). Made registratin to concentrations a gas NO2 provided in relative units. Primary task of the experimental studies was producing evaluation of potential possibilities of laboratory complex with provision for dispersion-diffusing characteristics of complex atmospheric ambience, reveal main theoretical and technical problems for the reason further modernizations testing device.

The total ozone amount (TOA) is determined as a rule by classic spectrophotometric method: TOA is found from a measured difference of the atmospheric optical thicknesses at two specially selected wavelengths in the region 305-340 nm. In this region the aerosol and molecular scattering takes place and it is traditionally believed, that the molecular absorption in this spectral region is conditioned only by ozone. Researches performed in the Institute of Atmospheric Optics SB RAS at the end of 1980s have shown, that there is also gentle absorption of a water vapor in this region, which can make a contribution to the measured difference of atmospheric optical thicknesses and can result in some methodical error. Thus, the TOA value which is determined without considering the water vapor, may be overstated.

The solution of the vector transfer equation in optically active media based on the Monte-Carlo method is considered. The algorithm suggested is used for studying the radiation polarization structure at narrow beams propagation. The preliminary polarization analysis has been made using a slightly anisotropy medium consisting of spherical particles. The particles are characterized by the index of refraction n=1.55 and have log-normal distribution. The phase and extinction matrices were calculated using the Green's function in the weak-anisotropy approximation.

The paper deals with radiation transfer in scattering volumes of various forms. Change of brightness body of scattering volume is analyzed by means of the asymmetry coefficient. The use of this coefficient allows appreciating the beginning of the remote mode and the utmost dimensions at which the medium can be considered unlimited in the cross-section. It also allows defining a transition region of optic dimensions at which the influence of absorption upon the brightness body form is significant. An invariant correlation was introduced which allows appreciating a precision of radiation balance calculation for scattering media of various forms.

A methodology is considered for the construction of a validation site with reference natural media to study scattering and radiation characteristics of underlying surfaces. The meteorological mast (313-m height) of SPA "Typhoon" was used to locate the spectral scanning instrumentation. The capabilities were discussed of the high meteorological mast and of the spectroradiomentric equipment developed to solve the problems of remote sensing. Presented are the specifications of the equipment and investigation results of some natural media obtained with a high spatial resolution under severely controlled meteorological and illumination conditions.

Temporal (diurnal) dependencies of statistical characteristics of the sky energy brightness spatial structure at the cover of cumulus clouds and different cloud amounts with the range of 8-13mcm are forecasted.

Steady plane-parallel isothermal turbulent flow of a viscous incompressible liquid above a surface with elements of a roughness is considered. Buildings and road with vehicle emissions for a city canyon. Reynolds equations and Boussinesq assumption are used to solve the considered problem. We apply the no-slip boundary conditions on the rigid walls, simple gradient conditions on the upper and outflow boundaries and known distributions of flow parameters on inflow boundary. Turbulent parameters are calculated on the basis of "k--ε" model of turbulence with near-wall functions approach for energy of turbulence k and dissipation ε. A numerical solution of the problem is found with using of finite-volume method and the SIMPLE algorithm. Influence of atmospheric parameters on pollutant dispersion in a street canyon is investigated. Also influences of the geometrical factors of a city street canyon on a pattern of turbulent flow and distribution of harmful impurity concentration emitting from urban vehicles are investigated. The adverse meteorological situations resulting in accumulation of the harmful substances in street canyon are shown.

The first results of the comparison of the transport-photochemical model LOTOS with measurements of the surface ozone and some of its precursor concentrations over European Russia are presented in the paper. The model is developed at the Netherlands Organization of Applied Research (TNO). Test runs were performed for the year 1997. Comparison of output parameters like surface ozone and nitrogen oxides concentrations was done using the measurement datasets of TROICA-3 expedition, EMEP measuring network and Kislovodsk High Mountain Station (KHMS). The surface ozone concentration measured at KHMS is in a good agreement with the modeled values if the second but not the surface level of the model is chosen. Comparison of hourly mean modeled concentrations with latitude profile of TROICA-3 expedition shows a substantial concentration underestimation while approaching the Ural Mountains and in the regions of strong emissions. The best agreement is observed while comparing model concentrations with EMEP measurements. The comparison showed that the model reproduces reasonably well the spatial distribution and temporal variability of the surface ozone concentration and that it can be used for the tasks of regional ozone monitoring.

The description of the web-portal ATMOS structure and the software for implementation of the system and the applied functions needed for this kind of a portal are presented. Database operation, session support, user identification, control of the user's data and dynamic formation of a menu, operation with the applications and templates for data representation are some of the system's functions. Almost all of the system's functions are used during the session realized on a scientific site. The set of the system's functions is called core. Parameters of the core for each site are stored in the database. The applied functions are implemented in the portal as two types of the applications. All the sites of the portal use service applications. Internet links archive, terminology thesaurus, embedded html-editor, etc. form these applications. Scientific applications are unique and as a rule are oriented for the subject field. The ATMOS web-portal consists of nine sites, six of which are clustered in a site group called Atmospheric Chemistry and Physics. The principal features of scientific site construction are discussed. This work was supported by the Intas grant (00-189).

In the given work the statistical characteristics of fluctuations of optical transfer function of optical system "turbulent atmosphere - telescope" are theoretically studied at registration of the averaged image and series of short-exposure of the images at processing by their methods of the speckle-interferometry. The following statisical characteristics of optical transfer function are examined: the mean value, the variance and the correlation functions. Besides the analysis of the statistical characteristics of the integral resolution of optical system "turbulent atmosphere - telescope" will be carried out. Are performed both numerical, and analytical calculations. Attention the influence of the outer scale of the atmospheric turbluence on optical transfer function of optical system "turbulent atmosphere - telescope" is given. Derived results allow to estimate degradation of the image, caused by influence of the atmospheric turbulence, and also to enter a quantitave estimation to concepts "very long" and "very short" exposures.

The accuracy of a high-precision interferometric experiment depends on both instrument errors and errors connected with processing the interferograms. Both types of errors can be minimized by an optimum adjustment of the functions of the basic unit of the system. The paper addresses the issue of error optimization using different adaptive systems within a laser interferometer design.

In this paper we undertake an attempt to take into account the effect of the underlying terrain (including mountainous terrain) in the regions of location of astronomical receivers on the variance of the image jitter for extraterrestrial objects. It is shown that taking into account the underlying terrain it is possible to achieve a good agreement between theoretical and experimental data that deviate significantly from the well-known theoretical secant law.

Statistical characteristics of a signal of the shearing interferometer when recording of the laser radiation propagating through the turbulent atmosphere have been theoretically investigated. Analytic relationships for the statistical moments of the shearing interferometer signal under the various conditions for optical radiation propagation through the turbulent atmosphere are derived. New methods for processing of the shearing interferometer signal are proposed. These methods allow one to decrease distorting effect due to atmospheric turbulence when reconstructing the initial field distribution.

Efficiency of an adaptive corrector intended for compensation of atmospheric turbulence is estimated using the model of flexible multiactuator mirror. Deformations of the mirror are represented as superposition of the response functions obtained as a result of numerical calculations. For approximation of the phase profile the algorithm was applied of phase surface sewing.

The algorithm of a segmented mirror co-phasing is described in the paper. The algorithm is based on the analysis of interference pattern, special criterion is introduced for this purpose. It is shown that initial shift of the segments must be less than half of the wavelength. To increase the dynamic range of the system the second (or even third) wavelength should be used in the algorithm. In this case the dynamic range can be increased up to 30 mkm.

The space and time evolution of the internal optical field intensity inside weakly absorbing micron-sized particles at diffraction of femtosecond laser radiation is studied numerically using the Fourier method in combination with the Mie theory. Peculiarities are found in the dynamics of formation of the spatial distribution of the femtosecond pulse intensity in particles at various pulse duration, laser beam shape, particle size, and illumination geometry. It is shown that at nonstationary diffraction we almost always observe resonant excitation of the internal optical field, at which the natural frequencies of one or several high-Q resonance modes of the particle fall in the central part of the spectrum of the incident pulse. This leads to the delay of the radiation in the particle and to the decrease of the temporally absolute peak of the internal field intensity as compare dto the stationary case. The decrease of the peak intenstity is the greatest in the case of exact resonance, when it may achieve several orders of magnitude. Illumination of the particle by a narrow Gaussian beam of femtosecond duration directed at the particle center gives a gain in the internal field intensity as compared to the edge incidence of the radiation.

The methyl-substituted phenols(o- and p-cresol) photolysis under UV-excitation from KrCl-laser in water solutions are presented. The irradiated solutions were investigated by spectroscopic methods. The comparison of the KrCl-laser irradiation effects with and without argon bubbling for phenol, o- and p-cresol was realized for the first time.

The quenching of triplet 4,4'-dimetylbenzophenone (B) by phenol (PhOH) and its halogen substituted analogs in aqueous micellar solution of sodium dodecyl sulfate as well as formation and decay kinetics of the corresponding radical pairs (RP) have been examined using the laser flash technique. The quenching kinetics was described in terms of PhOH distribution between micellar and aqueous phases. The distribution coefficients and rate constants of intramicellar quenching and PhOH escape from micelles were extracted using global kinetic analysis. A very pronounced internal heavy atom effect was observed for the RP yield and geminate recombination and attributed to the enchanced intersystem crossing within contact RP due to the spin orbital coupling. Application of an external magnetic field results in the RP decay even in the systems with minor contribution of geminate recombination.

The illustration of opportunities of processing optoacoustic signals with use of the developed software "atmospheric optoacoustic" is submitted, allowing in real time to compensate deforming influence of an atmosphere on quality registered optoacoustic to the information on character of distribution of pulse powerful laser radiation in an atmosphere.

The diffraction of narrow sharply focused beam propagating through the free space and nonlinear medium was studied. The validity of two approximated approaches for analysis of narrow beam diffraction was studied on the base of comparison with the solution of Kirchgof-Helmholtz diffraction. Both of these approaches is based on the particular solution of Helmholtz equation, which is corresponded with propagation of unidirectional wave. In the first of them attenuating waves are taken into account for the case where the spatial spectrum width is greater than the wave number. The second one is based on the neglect of contribution from attenuating waves. Also, validity of a parabolic wave equation for these situations was researched.

Diffraction of a train of femtosecond laser pulses at a weakly absorbing aerosol particle is considered based on the analytical solution of the Maxwell equations obtained through representation of light fields as series expansion in terms of electromagnetic eigenmodes of a dielectric sphere. The dynamics of formation of an optical field inside a transparent spherical particle irradiated by a single pulse and a train of ultrashort laser pulses is comparatively analyzed. It is found that when the particle is exposed to a series of laser pulses, both the evolution of the field inside the particle and its energy characteristics vary depending on the pulse repetition frequency. The analysis shows that the decrease of the gap between the acting laser pulses leads to the increase in the intensity of the internal field in the zone of its maximmum. As this takes place, the lifetime of the field inside the particle increases because the spectrum of the acting radiation become richer as compared to a single pulse and the probability of excitation of high-Q resonance modes in the particle is higher.

The investigation directed on creation a new physical methods of aerosol medium diagnostics is represented increasing interest now. For improve of existing diagnostic opportunities of flourescent techniques the theoretical study of the questions connected with the establishment a ratio of observable signal characteristics of multiphoton excitation fluorescence and physical - chemical parameters of aerosol particles is important. In this connection the angular characteristics of multiphoton excitation fluorescence (MEF) in microparticles is one of such interesting tasks.

A more detailed modeling of interactions between the solar radiation and smoke medium and also of mechanisms of radiative transfer between air and smoke media is required. One-dimensional models of solar-radiation transfer in the atmosphere-smoke system (SAS), i.e. atmosphere with admixtures that arose under the effect of large scale fires (forest, peat, industrial) and lead to forming extending smoke screen, are being developed by us on the basis of two approaches. In one model, calculations are performed by the iteration method of characteristics ofr a two-medium SAS: underlying layer - smoke screen, upper layer- atmosphere. The second model uses the optical transfer operator (OTO) to express the SAS radiation through the influence functions (IFs) of the atmosphere and smoke.

The model of a plane-parallel slab of a turbid medium is accepted, where there are particles of the spherical form scattering light separately from each other. Mathematically the problem is reduced to the solution of a boundary-value problem of a radiative transfer equation in turbid media with strong anisotropic scattering. In this case the computation of a backscattering is mathematically an ill-conditioned problem by using any numerical method of the solution. In the suggested method the backscattering radiance is determined by a SH method as a difference between the exact solution and SAA that essentially reduces the order of a system and smoothes the solution at any degree of an anisotropy scattering. As SAA the small angle modification of spherical harmonics method is chosen, which has a form of series of spherical harmonics that also enables to present a backscattering analytically. The calculation of medium parameters in model is made according to the Mie theory in the form of series of spherical harmonics, that allows to take into account the effect of physical properties of the medium on the radiation reflection.

A semi-analytical approach to compute the power and polarization of pulsed return signal in the bi-static sounding of a multiply scattering medium with forward elongated phase function, such as the sea water, tissue or a cloud, which is based on the signal consideration as resulting from the single scattering into backward directions and small-angle multiple scattering into near-forward directions, is briefly described. Possibility of radical simplification of the approach for small angles between the receiver and source axes is shown with using examples of light scattering in the sea water and tissue. Evaluated values of the return polarization as a function of the angle between source and receiver axes in the case of sea water sounding are presented.