The comparative assessment of all components of the PAR budget (incident on the sea surface, reflected from the rough sea surface, penetrating to the different depth in the water column, water-leaving and absorbed in water) made by using satellite and in situ data in the Barents, Black, Kara, and White seas is presented. Water quality is varied from clear with the diffuse attenuation coefficient Kd(555) ≈ 0.13 m–1 to very turbid with Kd(555) = 0.42 m–1. These differences cause the essential discrepancy of components of the PAR budget in different seas. An agreement between the estimates of PAR penetration in the upper layer derived from in situ and satellite data is quite satisfactory.

Results of researches of spatial correlation of atmosphere optical heterogeneities above the Black sea are presented. Measurements of aerosol optical thickness are carried out by two spaced sun photometers. The spatial correlation radius of aerosol optical thickness is estimated and constitutes in order of 160 km. Possibility of revealing the absorbing aerosols properties above the sea is shown on a concrete examples. The recommendations on application of portable photometers in sub-satellite measured experiments are given. 

One of the principle advantages of gliders is that they provide high-resolution measurements at small temporal and spatial scales. They also autonomously operate 24/7 under a variety of weather and sea-state conditions, they increase sample measurement densities (shipboard sampling 87 profiles day-1 as compared to 665 profiles day-1 from a glider), they are relatively low cost, easily re-locatable and finally, they have low power requirements for extended deployment periods. The goals of this study were (1) to determine the radiometric uncertainty of downwelling irradiance (Ed) measurements made from gliders, (2) to apply the Submerged Remote Sensing (SRS) technique for calculating mean K's (average K over some depth interval from just below the surface to the sensor depth) from validated glider Ed data and (3) to invert mean K's to local K's (K over some smaller depth increment ~1–2 m to generate a vertical profile of K) under varying incident solar fluxes (cloud cover/atmospheric conditions). 

The method for analysis of spatially - temporal distortions of a pulsed light beam in the stratified turbid medium with narrow scattering phase function (in particular, sea water) is developed. It is shown that the radiative transfer equation in the refined small-angle approximation is reduced to a set of equations for longitudinal moments of a pulsed light field which is solved rigorously unlike the analogous equations for temporary moments of pulse. Recurrence relations, which permit to calculate the moments of the higher order based on the zero moment, are obtained. The formulas for calculating the first three moments, defining the average radiance (or irradiance), the distance between the leading front and the “centre of gravity” of pulse as well as the longitudinal scale of its smearing, are given. Formulas for definition of time characteristics of pulse from its spatial moments are obtained.

The paper contains the data on measurements of depth distributions of attenuation coefficient and fluid density in the Barents, White and Kara Seas together with results of analysis the correlations between these distributions. We founded that in many cases correlations between parameters of the functions used for distributions approximation are rather high, namely, between the horizons of maximal change of attenuation coefficient and the pycnocline depth, between widths of pycnocline and the layer of attenuation coefficient jump, as well as between the gradient of c and the buoyancy frequency.

In 2004-08 the absorption properties of phytoplankton was measured in 15 northern Polish lakes of different trophicity. At the same time the concentrations of optically active substances in these lakes were also measured. These data were used to test the model of the absorption properties of phytoplankton, derived by Bricaud et al. for case 1 oceanic waters (hereafter referred to as Bricaud's parameterisation), to predict the spectra of light absorption by phytoplankton aph for lakes in Pomerania. This study shows the limitations of this model to lacustrine phytoplankton; and the reasons for them are discussed. In addition, an analogous model of light absorption by phytoplankton in the investigated lakes was derived on the same mathematical basis as Bricaud's model, but with different values of the relevant empirical parameters. For the sake of simplicity, the analysis covered the coefficients of light absorption only by surface water phytoplankton. The results were compared with those obtained for case 2 waters by other authors using similar models.

Commonly used optical models of natural waters have been analyzed in the context of their applicability in the Baltic Sea. By use of a large data set collected at the Baltic, we found that published before relationships between scattering, attenuation and backscattering coefficients at wavelength 550 nm in ocean waters are valid for Baltic as well. When the same data were used for validation of the relationships connecting absorption and scattering coefficients of the chlorophyll and absorption coefficients of Colored Dissolved Organic Matter (CDOM) with chlorophyll concentration, the result shows a large discrepancy, disqualifying them in the complicated environment of the Baltic Sea. 

A scheme of construction of imaging systems based on a complex modulated illuminating beam and the received echo signal processing is proposed, which involves the extraction of the modulated component and its matched filtering is discussed. The approached model of a signal taking into account the effect of surface waves and multiple scattering in water is constructed. The system limiting longitudinal and transverse resolutions determined by random light refraction on the surface and scattering in water are estimated. Characteristics of imaging systems with extremely high frequency of beam modulation are estimated.

New approach to MODIS data processing, joined of algorithm for sun glint area and low-parametric algorithm of atmospheric correction is presented. Software package processing MODIS imagery has been developed. Validation of this algorithm with in situ measurements of the water radiance reflectance ρ(λ) in most cases shows better accuracy then the SeaDAS 6.1 data as in the presence of sun glint and without glint. As a result of applying of new algorithm, the area of solving the inverse problem increased.

The objective is to determine the location(s) in any given oceanic area during different temporal periods where in situ sampling for Calibration/Validation (Cal/Val) provides the greatest improvement in retrieving accurate radiometric and derived product data (lowest uncertainties). A method is presented to merge satellite imagery with in situ samples and to determine the best in situ sampling strategy suitable for satellite Cal/Val efforts. This methodology uses satellite acquisitions to build a covariance matrix encoding the spatio-temporal variability of the area of interest. The covariance matrix is used in a Bayesian framework to merge satellite and in situ data providing a product with lower uncertainty. The best in situ location for Cal/Val efforts is retrieved using a design principle (A-optimum design) that looks for minimizing the estimated variance of the merged product.

This study defines hydrodynamic characteristics of underwater gliders based upon numeric solution of Reynolds-averaged Navier-Stokes equation. The characteristics were compared with experimental data and it was shown that it is possible to use numeric methods of viscous fluid dynamics for development of a shape of such objects. Mathematical model of glider's motion was designed. Feasibility of its use as a towing vehicle for another underwater object was studied. Analytical estimations of glider motion parameters were obtained at steady-state modes with and without account of towing force.