## «Processes in GeoMedia» Volume 4 (13) 2017

INFORMATION RESOURCES OF MARINE HYDROPHYSICAL INSTITUTE OF THE RAS

*T.V. Bayankina, E.A. Godin, E.V. Zhuk, A.V. Ingerov, E.A. Isaeva, A.Kh. Khaliulin*

*Marine Hydrophysical Institute of the RAS*

In Marine Hydrophysical Institute of the RAS (MHI) the work on the development of oceanographic databases has been conducted for a long time. In recent years, a number of databases of model calculation results have been created in MHI along with databases of observed data. The article considers some of the databases which were formed in MHI and some other MHI informational resources, as well as with the problems of oceanographic data quality control and providing database access.

Keywords: databases and data banks, the Black Sea, quality control, drifters, numerical modeling.

pp. 651-659

THE PROBLEM OF LATE QUATERNARY GLACIOISOSTASY IN THE DEVELOPMENT OF THE MOUNTAINOUS COASTAL SEA ZONE (ON THE EXAMPLE OF THE SOUTH GEORGIA ISLAND, ANTARCTICA)

*N.N. Dunaev*

*P.P. Shirshov Institute of Oceanology of the RAS*

To date, it appears that the South Georgia Island in late Quaternary time, was completely susceptible to glaciation of the mountain type, which in the reduced volume exists at the present time. At original research key-areas of the island it is established that main role of the glaciation is to supply terrigenous material to the coastal zone and adjacent shelf. In the present time glaciers contribute to the water flows in brief warming intra-annual periods and to the development of narrow pocket beaches composed of coarse-grained material in internal areas that are free from ice coves. The modern shores of the island were formed in the post-glacial global warming era under the influence of newest tectonics and hydrodynamic regime of the adjacent sea water area, the level of which does not exceed the current value. Manifestations of regional glacioisostasy are not detected.

Keywords glaciation, glacioisostasy, near-shore, eustatica, neotectonics, pleistocene, holocene.

pp. 660-667

CONTRIBUTION OF MATHEMATICAL MODELING IN ECOLOGICAL SAFETY SUPPORT OF THE SEA COASTAL ZONE (ON THE EXAMPLE OF THE VARADERO AREA, CUBA)

*N.N. Dunaev 1, I.O. Leont’ev 1, T.Y. Repkina 2, J.F. Herrera 3*

*1 P.P. Shirshov Institute of Oceanology of the RAS*

*2 M.V. Lomonosov Moscow State University, faculty of geography*

*3 Institute of Oceanology of the Academy of Sciences of Cuba*

Geological and geomorphological location is reviewed for the seaside-resort Varadero which is recreational area of international importance. The outlook on the natural scenario of this area evolution is of great concern. The analysis of coastal morpho-and lithodynamics is inplemented. The interpretation of the term «coastal zone» is given along with the approach to the identification of its boundaries and components. The materials obtained formed the basis of a mathematical model characterizing the lithodynamics component of the studied area evolution. Specific measures to preserve beaches from erosion by storm waves are proposed.

Keywords: near-shore coastal zone, ecology, modeling, artificial beach.

pp. 668-677

CLASSIFICATION OF THE REGIMES OF THE STRATIFIED VISCOUS FLUID FLOWS AROUND DISC

*P.V. Matyushin*

*Institute for Computer Aided Design of the RAS*

The paper presents the results of the mathematical modeling of the linearly density stratified incompressible viscous fluid (SIVF) flows (described by the Navier-Stokes equations in the Boussinesq approximation) around a disc (with diameter d and thickness H = 0.76d) uniformly moving in a horizontal direction along its axis of symmetry z with velocity U. The process of the 3D vortex structures of the steady-state SIVF flows transformation around a disc (consisting of a wake and internal waves) with decreasing of the internal Froude number Fr = U/(Nd) from ∞ to 0.05 is described in detail for Reynolds numbers Re = U∙d/ν = 50 and 500 (where ν is kinematic viscosity coefficient of SIVF, N is buoyancy frequency of SIVF). A classification of the regimes of SIVF flows around the disc is constructed for Re ≤ 500 in a wide range of Fr numbers on the base of the serial calculations performed on the supercomputers of JSCC RAS.

Keywords: stratified viscous fluid, diffusion, internal waves, crest, trough, convective cell, disc, visualization, 3D vortex structure, mathematical modeling.

pp. 678-687

IMPACT OF HYDRODYNAMIC PERTURBATIONS ON DISPERSION CHARACTERISTICS OF A NEAR-SURFACE WATER AEROSOL

*V.N. Nosov 1, S.G. Ivanov 1, V.I. Pogonin 1, V.I. Timonin 2, E.A. Zevakin 1, N.A. Zavyalov 1, A.S. Savin 2*

*1 V.I. Vernadsky Institute of geochemistry and analytical chemistry of the RAS*

*2 N.E. Bauman Moscow state technical university*

Influence of two different types of hydrodynamic perturbations on the characteristics of laser radiation scattering in the near-surface aerosol layer are carried out. Laboratory experiments are made in tray with running and quiescent aerated water. First type of hydrodynamic perturbations are created by a streamlined obstacle at the tray bottom, second ones – by rotating propellers. Two sorts of statistical amplitude distribution of red laser light scattering in a near-water aerosol located above the perturbation region were established. The amplitude distribution histograms of light scattering are compared and discussed.

Keywords: aerated aqueous medium, near-surface water aerosol, hydrodynamic disturbances, registration of light scattering.

pp. 688-692

INVESTIGATION OF THE INFLUENCE OF BOUNDARY CONDITIONS ON THE RESULTS OF THE ROCKFALL MODELING

*N.S. Orlova 1,2, M.V. Volik 2,1*

*1 South mathematical institute of the Vladikavkaz Scientific Center of the RAS*

*2 Financial University under the Government of the Russian Federation*

The rockfall movement of the slope, which is associated with the horizontal section, is described. The rockfall simulation is performed with use of redistributable package OpenFoam for of applied problems of hydro- and aerodynamics solution. Continuum approach and kinetic theory of granular gas are used. The effect of the boundary conditions for the velocity of the rockfall mass on its distribution is investigated. Calculations are performed for various boundary conditions. Two-dimensional numerical calculations of distribution of rockfall mass are presented. The results of the calculations showed that the model can be used to simulate the rockfall movement and to estimate the rockfall damage zones. It is also shown that the adhesion condition or weak slip condition are more preferable to use as a boundary condition for the rockfall mass velocity.

Keywords: mathematical modeling, rockfall, fluidization, continuum approach, kinetic theory of granular gas, adhesion and slip conditions, OpenFoam, twoPhaseEulerFoam.

pp. 693-699

COMPARATIVE EVALUATION OF ACCURACY OF NUMERICAL WAVE MODELS BASED ON SATELLITE ALTIMETRY DATA

*V.G. Polnikov 1, N.S. Zilitinkevich 1, F.A. Pogarskii 1, А.А. Kubryakov 2, 3*

*1 A.M. Obukhov Institute of atmospheric physics of the RAS*

*2 Marine Hydrophysical Institute of the RAS*

*3 St.-Petersburg state university*

A technique developed for selection of along-track data of altimeters in accordance with their binding to the data of buoy measurements and data of two wave models: WAM4 and its modified version – WAM4-M. The root-mean-square deviations (RMSD) of the model data of the wind wave heights from the calibrated altimetric data in the Indian Ocean for the period 2013–2015 are estimated. The RMSD are shown to have significant variability over space. The advantages of WAM4-M over WAM4 model in terms of the standard and corrected RMSD for the different zones of the Indian Ocean and the entire ocean are established. The reasons for the variations of the RMSD of the two study models are discussed in dependence on the zone of the Indian Ocean.

Keywords: altimetry, along-track data, calibration, verification of the wave model.

pp. 700-709

INFLUENCE OF WAVE TRANSFORMATION ABOVE THE UNDERWATER BOTTOM RELIEF FEATURES ON THE RETREAT OF THE SHORE LINE DURING THE STORM

*Ya.V. Saprykina 1, O.A. Kuznetsova 1, 2*

*1 Shirshov Institute of oceanology of the RAS*

*2 N.N. Zubov State Oceanographic Institute*

Mathematical modelling has shown that a decrease in wave energy during the transformation of waves over the features of the underwater bottom relief does not always lead to a decrease in the degradation of the shoreline. This depends on the change in the mean wave period determined by the differences in the dissipation intensity of the low- and high-frequency parts of the wave spectrum. The increase of mean wave period leads to erosion, and the decrease to sediment accumulation in the area of shoreline. It is shown that in the case of large dissipation of wave energy of higher nonlinear harmonics during the propagation of waves over underwater structures, in particular over one underwater reef, despite the decrease in the total wave energy, the main wave period may increase, that may cause a retreat of the shoreline.

Keywords: nonlinear wave transformations, underwater structures, mean wave period, wave energy dissipations, transmission coefficient.

pp. 710-716

THE CHOICE OF THE AREAS WITH MINIMUM STORM IMPACT UNDER THE EXTREME WEATHER CONDITIONS

*A.A. Solovyev 1, D.A. Solovev 2*

*1 M.V. Lomonosov Moscow State University, faculty of geography*

*2 P.P. Shirshov Institute of Oceanology of the RAS*

The paper presents the results of using the graphical-analytical method of determining the optimal placement for large-scale floating power plants in the offshore area of the sea in extreme weather conditions. The regions with the minimum energy of the storm impact on floating structures are defined for the area of the Black sea experimental polygon. It is shown that in these areas there is a convergence of waves, thus refraction has no effect on the wave height and no devastating effects on the floating energy plants. The results of the calculations have been confirmed by observations during the annual experimental tests with appropriate accuracy, and can be applied for the design of floating power plants dislocation areas.

Keywords: extreme weather conditions, refraction, waves, floating power plants, renewable energy.

pp. 717-724

FACTORS CONTROLLING THE ANNUAL VARIABILITY OF THE CHLOROPHYLL CONCENTRATION IN THE NORTH-WESTERN PART OF THE BLACK SEA

*M.V. Tsyganova 1, 2, E.M. Lemeshko 1, 2*

*1 Marine Hydrophysical Institute of the RAS*

*2 Black Sea Hydrophysical Proving Ground of the RAS*

The main objective of this research is to study the interannual variability of the chlorophyll concentrations in the North-Western part of the Black Sea which is related to the physical factors. Using the numerical model of the shallow sea dynamics, the influence of the Danube river inflow on the formation of the hydrological structure of waters and circulation features on the Northwestern shelf of the Black Sea and its influence on the spatial variability of the chlorophyll concentration is investigated. The Self-Organization Map (SOM) analysis is applied to identify typical (recurrent) spatial patterns of chlorophyll concentrations and their interrelations with information on physical forcing.

Keywords: chlorophyll, numerical modeling, plume, Self-Organizing Map, Danube river, coastal dynamics, Black Sea.

pp. 725-730