Viktor V. Fadeev

Possibility of standardization of normalized fluorescent parameter as a measure of organic admixture concentration in water and atmosphere

Fluorescence of organic admixtures in water and atmosphere is the main information source for express diagnostics of the environment. A quarter of century ago it was proposed to normalize fluorescence intensity to the intensity of Raman scattering by molecules of the main component of medium (water in water medium, nitrogen in atmosphere) and to measure the normalized fluorescent parameter (Phi) O equals IflO/IRS, where IflO is fluorescence intensity (or number of photons) of the admixture in absence of saturation, IRS is the intensity (or number of photons) of the Raman scattering by water (or nitrogen) molecules. In fact, the parameter (Phi) O is the fluorescent signal from unit volume (of water or atmosphere) normalized to the intensity of exciting optical radiation. Some requirements being fulfilled, the parameter (Phi) O is a linear measure of concentration of the admixture, independent of characteristics of medium and device, therefore, it can be proposed as a standardized parameter in fluorescent diagnostics of organic admixtures. These requirements are analyzed in this paper. The stability and controllability of some parameters which determine the value of the coefficient (alpha) in the formula C equals (alpha) (Phi) O (where C is the admixture concentration) are discussed in this paper. These parameters are: (1) relative dispersion of the attenuation index (Delta) (epsilon) /(epsilon) , where (Delta) (epsilon) equals (epsilon) ((lambda) fl)-(epsilon) ((lambda) R); (2) fluorescence cross section of the admixture, and (3) Raman scattering cross section of water (nitrogen). The analysis showed that the fluorescent parameter (Phi) O can be an independent characteristic of organic pollutants content in water (or atmosphere) parallel with the other optical indices of water quality (or atmosphere quality), for example, coefficients of absorption and of scattering, colorness index etc.

New opportunities in solution of inverse problems in laser spectroscopy due to application of artificial neural networks

Inverse problems in laser spectroscopy are reported to be successfully solved by application of artificial neural networks, a powerful data processing technique that performs better than traditional variation algorithms of solving inverse problems.

Origin and structure of fluorescence band from aquatic humic substances

The different spectral-luminescence characteristics of humic substances were investigated. Hypothesis for the origin and the structure of fluorescence band from humic matter are discussed.

Laser diagnostics of water ecosystems: conception and methods

A description of the general principles being developed at Moscow University for laser diagnostic methods of monitoring water ecosystems is presented in the present paper. A brief historical survey of investigations in this field is provided with the formulation of the problems which should be solved. The latest results obtained in Moscow University are summarized. These results are discussed in a series of papers presented in these proceedings and reported at several recent international conferences.

On the potentiality of using the fluorescence of humic substances for the determination of hydrological structures in coastal sea waters and in inland water basins

This paper describes the potentialities of the characteristics of the fluorescence of humic substances (HS), namely, their intensity normalized to the Raman band intensity of water and the shape of their fluorescence band, as indications of the hydrological structures of the surface water layer in marine coastal areas (using the example of the North Sea region near the East Frisian Islands and the estuary zone of the Weser River) and in inland water basins (using the example of the Rybinsk Reservoir). We demonstrate that the HS fluorescence band’s shape parameters allow stricter discrimination of the dominant water masses as compared to the admixtures’ concentration-related indicators (the salinity, electric conductivity, and HS fluorescence intensity).

Lidar mapping of phytoplankton and organic matter distributions in the Baltic Sea

The results of simultaneous lidar monitoring of phytoplankton (PP) and organic matter (OM) horizontal distributions in the subsurface layer of the Baltic Sea are presented in the paper. A special shipboard lidar system has been developed. Total length of the monitoring route was 8390 km. The horizontal distributions of near-surface PP and OM for the second half of May and the first ten days of June were reconstructed using the data obtained. The polluted areas near the industrially active regions were detected. Diurnal rhythms of PP fluorescence were measured in situ by lidar. It proved the necessity of adjustment of lidar data for such diurnal variations. The temporal divergence of detected structures was explored. For most parts of the area, averaged time of divergence for phytoplankton horizontal distribution was estimated as 1.2% per day.

Complex system for optical monitoring of coastal marine water areas: concept and methods

The concept of a system for continuous express monitoring of coastal sea water areas is presented. According to the suggested concept, the monitoring system should consist, in general, of three parts, in which the key role should belong to laser devices: (1) shore-based lidar that performs continuous monitoring of water surface and sub-surface layer of water (and, possibly, of atmosphere) in the selected water area; (2) patrol boat equipped with submerged portable devices, including laser spectrometer with submerged optical fiber probe; (3) coastal laboratory equipped with devices for detailed (but express enough) analysis of water samples, specially chosen by the results of remote laser sensing and submerged device data. Some features of remote sensing by means of shore-based lidar are considered. The main feature is sliding incidence of laser beam to water surface. The coastal sea waters have much more complex and variable composition than open sea water. The possibilities of different versions of laser fluorimetry in diagnostics of organic compounds in coastal sea waters are analyzed.

Laser remote sensing of dissolved organic matter in natural water

Fluorescent methods using Raman scattering signal as an internal standard are widely applied for environment remote control of dissolved organic matter (DOM) in water. In this paper temperature variations, ultraviolet irradiation influence on exitation and emission spectra of water samples have been investigated. Photochemical processes in DOM under laser excitation and the effect of fluorescence saturation have been studied.<<ETX>>

Diagnostics of primary photosynthesis processes by laser saturation fluorometry

New results of application of laser saturation fluorometry, relying on the measurement and analysis of nonlinear characteristics of laser-induced chlorophyll-a fluorescence, for study of primary photosynthesis processes and diagnostics of unfavorable environmental influences (nutrients depletion; presence of herbicides, heavy metal ions, etc.) on alga photosynthetic apparatus are reported. Mechanisms of the changes in fluorescent characteristics under these influences as well as structural and functional modifications to photosynthetic apparatus, causing these changes, are analyzed. It is shown that the laser saturation fluorometry permits to selectively identify different environmental influences oppressing photosynthesis.

Determination of the photosynthesizing organisms photophysical parameters by the method of nonlinear fluorimetry

There is a set of discussed questions in the study of primary processes of the photosynthesis. Solution of these problems stimulates development of new methods for determination of the photo synthetic unit photo physical parameters in-vivo. In the report possibilities of non- linear fluorimetry method in this problem are investigated. The first step requires creation of low-parametrical model of the photosynthesizing organisms fluorescence response formation. The corresponding inverse rpobe4lm can be solved for this model.