Small sets of chemical kinetics equations for reactions with the water monomers and dimers are solved. Equilibrium complex concentration distribution as a function of the complex dimension at the number of monomers in a complex up to 10 shows a nonmonotonic form for some values of the total monomer unit number and reaction rates with tetramers and dimers.
An approach is presented which allows visual and quantitative trust assessment of composite multi-paper plots, where the results of the graphical representation of calculation or measurement results from different publications are compared. Using plots from the W@DIS IS collection, which characterize the continuum absorption, as an example, we show the procedure of construction of a composite multi-paper plot.
Small sets of chemical kinetics equations describing the cluster formation of complexes in water vapor are investigated. Sets of equations for N≤10 are solved by means of the implicit Eulerian method of the first order of accuracy for the model systems with unit rate constants and with real rate constants available in the literature. The character of cluster concentration distribution in the steady state as a function of their dimensions is changed at variations of the total monomer number A.
Small sets of chemical kinetics equations describing the formation of complexes in water vapor in the particular case of a system containing four molecules of water (monomer) with reaction rates equal to 1 are investigated. The steady state of the system is a stable focal point in the monomer-dimer plane and a complex singular point in the trimer-tetramer plane. The algorithm for deriving equations in the case of arbitrary number of monomers is described, convenient for program realization.
This paper provides the results of selective systematization of about 55 compound plots, gathered from 41 publications on weakly bounded complexes of molecular nitrogen and oxygen. This systematization enables the system to organize semantic search of the processed spectral functions and internal integration of graphical resources for each of the molecular complexes.
Results of the work on systematization of scientific plots characterizing the spectral functions related to the continuum absorption of water vapor are discussed. The plots systematized are available for researchers in W@DIS (wadis.saga.iao.ru) information system. The plots can be used for the comparison both between them and with userdefined computed data and measurements.
The results of calculations of the H_{2}O continuum absorption coefficients for IR spectra in 1000-1300 cm^{-1} and 2000-2700 cm^{-1} regions and absorption coefficients in the wings of the CO_{2} bands in the IR spectrum are presented. It is shown that the calculation of the local line contribution to the total absorption should be related to the line shape so that the maximum boundary of local line contribution does not fall into the region of frequency detunings corresponding to the exponential decay. The tendencies to a change of the continuum absorption with variations in the local line contribution boundary remain the same in cases of using both the experimental coefficient and calculated according the asymptotic line wing theory as the total absorption coefficient.
An approach is suggested to the formation of applied ontologies in subject domains where results are represented in graphical form. An approach to systematization of research graphics is also given which contains information on weakly bound carbon dioxide complexes. The results of systematization of research plots and images that characterize the spectral properties of the CO_{2} complexes are presented.
Small sets of chemical reactions involving four water monomers with real values of the rate constants and concentrations are discussed. The steady states and the molecular complex concentrations as functions of the total concentration and the rate constants of the reactions between dimers are examined. It is found that the concentrations of complexes in their approach to a steady state pass through a state with very slowly changing concentrations.
Formation of molecular water complexes that presumably affect the continuum water vapor absorption under nearatmospheric conditions is discussed within a chemical kinetics approach. Small sets of reactions responsible for a homogeneous nucleation of complexes comprised of simple structural units (water monomers) are considered. Sets with complexes containing no more than 5 monomers are examined. Steady states are found for the sets of model equations used, and the stability properties and time dependent concentrations of molecular complexes near the physical steady state are defined. The special features inherent in the behavior of the concentrations depending on the initial conditions and fraction of a foreign gas are revealed.
The current status of the W@DIS information system used for the systematization of spectroscopic data, including rovibronic transitions and energy levels, and data sources is reviewed, where the abbreviation W@DIS stands for Water Internet @ccesible Distributed Information System. Functionalities of W@DIS are outlined. The primary emphasis of W@DIS is on properties of data sources characterizing data quality. Several examples describe the interfaces used to create molecular spectral line lists and representation of binary relations between data sources and typical individuals of the ontology of information resources, states and transitions. The discussion employs the water molecule as an example.
The water vapor absorption in the 195–260 GHz region is investigated using asymptotic line wing theory. A knowledge of the absorption by the H_{2}O lines of the rotational band where the shape of the line wing provides an adequate description of the water vapor absorption data in the 300–1000 cm^{-1} interval is not enough to reproduce the absorption data for the microwave region. While asymptotic line wing theory treats the absorption by any colliding molecular pairs and ignores that due to bound dimers, the experimental absorption data reveal the fraction of absorption by the bound water dimers. The role of the local spectral line contribution to the evaluation of the dimer absorption is discussed.
Proc. SPIE. 10035, 22nd International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics
KEYWORDS: Visualization, Signal attenuation, Argon, Spectroscopy, Molecules, Composites, Digital imaging, Molecular spectroscopy, Temperature metrology, Absorption
The problem of systematization of published scientific plots presented in graphical form suitable for computer processing is discussed. The purpose of the present work is to briefly introduce a GrafOnto information system (part of W@DIS) for graphical representation of measured and predicted spectral functions relevant to molecular complexes, using Н_{2}О as an example. Steps involved in the formulation of the problem at hand are described. A digital image model for a scientific plot is built, and a GrafOnto system for creating composite plots that comprises applications and their associated interfaces is constructed.
Proc. SPIE. 9680, 21st International Symposium Atmospheric and Ocean Optics: Atmospheric Physics
KEYWORDS: Databases, Chemical species, Spectroscopy, Molecules, Data acquisition, Molecular spectroscopy, Chemical elements, Cesium, Binary data, Quantum information
Problems underlying a systematization of spectral data on the methanol molecule are formulated. Data on the energy levels and vacuum wavenumbers acquired from the published literature are presented in the form of information sources imported into the W@DIS information system. Sets of quantum numbers and labels used to describe the CH_{3}OH molecular states are analyzed. The set of labels is different from universally accepted sets. A system of importing the data sources into W@DIS is outlined. The structure of databases characterizing transitions in an isolated CH_{3}OH molecule is introduced and a digital library of the relevant published literature is discussed. A brief description is given of an imported data quality analysis and representation of the results obtained in the form of ontologies for subsequent computer processing.
The applicability of the ck-correlation approximation for certain spectral intervals in the 9.6 μm O_{3} band is examined. The problems of the optical thickness correlation and of the ck-correlation approximation assessment are discussed.
A line-by-line calculation of the continuum absorption coefficient with the wing line contour describing the absorption in different windows outside of the water vapor bands in the 4000–8000 cm^{-1} spectral region is presented. The continuum absorption calculated with the line wing contour characterizing the absorption in the 5800–6400 cm^{-1} window is shown to be close to the total absorption. Hence it follows that the absorption in the 5000–5500 cm^{-1} and 6900–7700 cm^{-1} bands is almost entirely due to metastable dimers and free complexes.
The self-broadened H_{2}O continuum absorption data for the 3−5 μm window available in the literature are described in the framework of asymptotic line wing theory. Use is made of a diffusion model taking into account violation of the long-wave approximation in spectral line wings.
Factors influencing the determination of the continuum absorption have been assessed, using the 4.3 μm CO_{2} band as an example. The local contribution to the total absorption plays a primary role in the case where the continuum absorption is obtained from experiment. The continuum absorption may be found unambiguously from absorption measurements in band wings. For measurements within the bands, the local contribution can be calculated as the difference between the total measured coefficient and the continuum contribution obtained from measurements in band wings.
The vibrational dependence of the Н_{2}О-N_{2} interaction potential due to the line shifts and line wing absorption in the 3−5 μm region is discussed. Evidence in favor of the vibrational dependence of the repulsive part of the potential is given.
A line-by-line calculation of the continuum absorption coefficient in the 1600 and 3600 cm^{-1} water vapor bands with the line wing shape corresponding to asymptotic line shape theory is presented. The calculation results agree closely with quasi-bound dimer absorption estimates made in the context of a dimer hypothesis. An examination of the classical part of the problem at hand enables the fraction of the quasi-bound dimers to be estimated.
Intermolecular interaction potential appears to be a value which performs the relationship between divisions of physics
seemingly far from each other. Accurate consideration of the quantum problem of interacting molecules allows one to
refine the employment of theoretical expressions for the potential describing one or other type ofprocesses. Thus, the
potential which can be named classical one is common for the absorption coefficient in the line wing and for the second
virial coefficient. This fact provides a possibility of using the temperature dependent classical potential obtained from the
line wing absorption coefficient data for the calculation of the second virial coefficient. The use of the line wing
absorption coefficient following from the line wing theory, which is appreciably defined by the behaviour of the classical
intermolecular interaction potential, leads to noticeable changes in the cooling rates at large heights in some spectral
regions.
Estimate is made of conditions which could lead to a possibility of solar radiation penetration to the Earth surface in the
UV region. The altitude behaviour of the transmission for some frequencies is considered under variations of absorbing
species concentrations. The value of the O_{2} absorption coefficient is diminished by a factor 10 for modelling the
absorption in the transparency microwindows, therewith the ozone and water vapour content is varied. At variations of
concentrations of absorbing species the transmission function of the solar radiation calculated from the upper bound of
the atmosphere downward remains zero near the surface in microwindows of the Schumann-Runge bands. It appears,
however, that near 210 nm the solar radiation may reach the surface at definite variations of concentrations of absorbing
species.
Water vapor transmission function calculations are performed in the case of nonhomogeneous atmospheric paths based on the exact formulas for the coefficients of expansion into the series of exponents that we obtained earlier. A comparison of the results obtained with the exact formulas and those obtained in the context of the correlated k distribution (CKD) approximation shows that the CKD approximation is successful due to the fact that the optical thicknesses are the real correlating values in the Earth atmosphere, whereas the differences in the absorption coefficient behavior for various thermodynamic conditions are not of great importance in this problem. Situations in which the CKD approximation may break down are pointed out. It is noted that the accuracy of the expansion into a series of exponents depends on the accuracy of the absorption coefficient corresponding to the abscissas of the quadrature formulas more than on the number of points. Cases are mentioned in which the CKD approximation gives results far from the line-by-line results, whereas a calculation that uses exact formulas works well in these cases.
Proc. SPIE. 5396, Tenth Joint International Symposium on Atmospheric and Ocean Optics/Atmospheric Physics. Part I: Radiation Propagation in the Atmosphere and Ocean
KEYWORDS: Signal attenuation, Aerosols, Error analysis, Ocean optics, Atmospheric physics, Ozone, Solar radiation, Atmospheric particles, Atmospheric optics, Absorption
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 purpose and functional capabilities of the Web information-computational system (ISC) 'Atmospheric Spectroscopy' (http://spectra.iao.ru) are presented. ISC is oriented on operations with databases of the high resolution spectra and designed for both placing at one's disposal the reference information on these spectra and solving traditional problems of the atmospheric optics. The experimental results on absorption by line wings and the possibility to calculate the absorption using different theoretical and empirical line wing shapes are discussed in the case of the CO_{2} and H_{2}O molecules. The basic concepts of the atmospheric spectroscopy used under the ICS designing are described.
Current state of the Internet accessible integrated information-computational system Atmospheric Optics and its usage as a background for the propagation problem consideration are reported. The system joins the results of experimental and field measurements of optical characteristics of atmosphere gathered at the Institute of Atmospheric Optics with developed theoretical models for computation and prognosis of optical properties of the atmosphere. It integrates currently the following interrelated topical subsystems: atmospheric chemistry, atmospheric radiation, molecular spectroscopy and statistical models of the atmosphere designed on the base of Internet technologies as sites in the Web. As an illustration of the possible system usage the propagation of the laser radiation along the chosen atmospheric path is considered.
Reported is the description and current state of the project `Information-Computational System `Integrated Model of Atmospheric Optics'. The system will incorporate the sets of data of the atmosphere, compiled during laboratory and field measurements conducted at the Institute of Atmospheric Optics experimental and theoretical models developed for forecasting and calculation of the latter. At the first stage the Integrated model will comprise only a few blocks, namely, the block of aerosols, molecular spectroscopy, atmospheric radiation and the photochemistry block.
Results are presented of the authors' approach to prognosis of possible qualitative changes in the long-term behavior of complex atmospheric-optical processes on the base of the nonlinear dynamics analysis of the corresponding low-order model. In particular, the behavior of chemical composition of the atmosphere determining its optical properties in many respects is discussed. To this end the qualitative analysis of dynamics of the pure oxygen atmosphere within the box model is fulfilled and conditions of appearance of multiple steady states are determined. It is shown that a simple model relating the kinetics of oxygen components, water vapor and molecular hydrogen allows one to predict different types of behavior of oxygen components in the hydrogen- oxygen atmosphere.
The atmospheric chemistry information-computational system (ICS) with Internet access is presented. The ICS is aimed summarizing fundamental data on atmospheric processes, determining the dynamics of complex chemical systems and providing educational information. The system consist of three functional blocks: data preparation, computation and information blocks, within which a user may choose the chemical reactions and atmospheric models, drive relevant kinetic equations and conservation laws, solve the kinetic equations, visualize the results of calculations and get access to related information.
Absorption coefficient of the water vapor was obtained in laser measurements in Ref. 1 in spectral region 930 - 990 cm_{1} at temperatures from 263 K to 300 K. In this paper, the water vapor selective absorption in this spectral region is calculated and subtracted from the experimental data_{1} to determine the 'experimental' continuum absorption. Continuum absorption calculated using some empirical relations in compared with the 'experimental' one to study its temperature dependence.
Proc. SPIE. 3583, Fifth International Symposium on Atmospheric and Ocean Optics
KEYWORDS: Near infrared, Solar radiation models, Data modeling, Signal attenuation, Solar radiation, Climatology, Performance modeling, Atmospheric modeling, Atmospheric optics, Absorption
Integral transmission functions in near infrared region of spectrum were extracted from the benchmark calculations of the solar radiation fluxes for the mid-latitude summer atmosphere. Their comparison with the values obtained from empirical formulas shows a good agreement. Hence, the transmission functions resulting from both ways can be used in climate modeling.
Within the framework of the line wing theory the peculiarities of line shape behavior in the intermediate part appear as a result of specific construction of the profile transitional from the line center to the line wing. In this paper it is shown that the experimental data in this case are satisfactorily explained.
I t i 5 we 1 1 known t hat the spectral 1 i ne shape i s def i ned as F(w) = :f P(WWjf)I<fXi<I (1) where i,f denote the initial and final states of the absorbing system, w= wi_ W is the transition frequency, X is the dipole moment operator, p is the density matrix of the system. The system under consideration is the molecular gas in a volume treated as a unified quantum-mechanical object. It can be seen from Eq. ( 1 ) that the 1 me shape is the result of stat ist ical averaging of the delta-function of the argument representing the energy conservation law under the absorption. For calculating F(w) the exact state energies and wave functions of the system or, after transition to the binary approximation, the wave functions and states of two interacting molecules and the characteristics of the statistical ensemble should be available. Usually the expression describing F(c) in term of the correlation function c(t) is used in calculat ions
The values of absorption coefficient κ in the wings of the infrared CO_{2} Q-branches significantly differ from those isolated Lorentzian lines. It becomes now traditional to explain these deviations by line-mixing. Actually, presence of the small line separations in the Q-branches are greatly conductive to this point of view. It can be noted, however, that the largest deviations from the Lorentzian line calculations are observed in spectral regions comparatively far from the line centers. Therefore it would be interesting to know whether the line wing theory can be used to describe the observed frequency dependence of κ or not. The present study concerns with the CO_{2} Q-branch at 1932cm^{-1}.
The absorption coefficient at a given frequency can be roughly represented as a sum of two terms. One of them accounts for absorption at the nearest line and another represents some background due to absorption at a distant line. This intuitive representation has been used for a long time, especially in studies of the absorption by water vapor. In this case, probably for the first time, special term was introduced for the second term, namely, the continual absorption. The contributions of these two constituents in one and the same spectral region can drastically vary under different thermodynamic conditions.
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