2016, volume 9, issue 1
This special issue is devoted to the 50th anniversary of the Saint-Petersburg Department of the P.P. Shirshov Institute of Oceanology of RAS. The issue presents the results of scientific researches in various fields of hydrophysics which were done in the Department. Based on the numerical modeling of potential liquid motion with a free surface the unfamiliar properties оf surface waves are studied. The results of modeling of the Barents Sea’s regional climate using direct and indirect means of allowing for tidal effects are presented. The opportunities and restrictions of modeling of nonhydrostatic dynamics of straits of the World Ocean are discussed. On the base of three-dimensional modeling the effect of ice on the primary production of phytoplankton in the Barents Sea is estimated. The evolution of a single internal wave is simulated with 3-D non-hydrostatic finite element model «air-water», factors which influence at damping speed are analyzed. Intraseasonal, synoptic and mesoscale dynamics of major hydrological fronts in the White Sea is studied based on the high-resolution satellite and shipboard observations. The expediency of the continuity equation’s modification is discussed, the derivation of this equation and its possible place in the system of fluid mechanics equations is assessed. New methods of determination of light scattering coefficient of natural waters and artificial ponds are presented, the possibilities of its practical implementation are described. The problem of monitoring and forecasting of personal environment is discussed.
2016, volume 9, issue 2
This issue contains general and applied problems of hydrodynamics; hydroacoustic researches are presented; the results of a digital model of the components of the Earth’s magnetic field are given. A reciprocity principle for long waves on shallow water propagating on the rotating Earth is analyzed. Unstable solutions of an equation of potential vorticity evolution in a long-wave approximation which are applied to describe the large-scale intrusions typical for the Arctic Basin are considered. Based on numerical experiments hydrobiological processes are studied during dredging in the delta region of the Northern Dvina and the disposal site in the White Sea. An effect of intense internal waves on towed hydrodynamical depressor is considered on the basis of observations carried out at Mascarene Ridge in the Indian Ocean. A mathematical model of hydrodynamic bottom pressure spectra depending on the parameters of wave spectrum and estimation of model coefficients is proposed. Methodological aspects of determination of coefficients of rotary derivatives of hydrodynamic forces and moments of underwater objects are discussed. A wave acoustic model of gas-liquid mixture, obtained on the basis of microscopic model of the dynamics of a heterogeneous medium is considered. A new adaptive algorithm intended for detection of weak signals based on the algorithm of classical type is suggested; it is compared with a well-known Capon algorithm. The algorithm of a joint use of energy and dynamic methods is used for the modeling of the accuracy of passive ranging. The results of researches on the study of the Earth’s magnetic field are presented; new problems in building the foundations of a spatial digital model of a component model of the Earth’s magnetic field are discussed.
2016, volume 9, issue 3
The issue contains hydrophysical topics on geology, climatology and experimental oceanology, practical hydroacoustic problems are discussed as well. The ways of experimental research of scale effects for fractured Earth’s crust of continents and oceans are considered. The mechanism of formation and evolution of mud volcanoes and near-surface accumulation of gas hydrates in Lake Baikal is investigated by means of the numerical modelling. The results of experimental studies of dynamics of methane bubbles clouds from a bottom of Lake Baikal to its surface with a formation of bubble jet «flare» are given. The data about spatial and temporary fields of the air temperature and the depth of the stably-stratified boundary layer of the atmosphere over the territory of the Northern hemisphere are generalized. The use of wavelet transform for the analysis of spatial and temporal variability of hydrological and hydrooptical observations data and their synchronization rate is observed. The results of the experimental modeling of oil spill spreading in vessel’s wake current from «ship to ship» mooring are presented. Based upon numeric modeling the hydrodynamic characteristics of an underwater glider are defined. The results of experimental and numerical studies of the regularities of formation of acoustic fields generated by low-frequency pulse signals propagating from the shelf into the deep sea are discussed. The ways of optimization of weight coefficients of cylindrical sound transparent antennas are shown.
2016, volume 9, issue 4
The issue presents papers on large-scale processes in the atmosphere, a modeling of currents of various existential scales, results of experimental oceanologic observations and practical hydroacoustic tasks as well. In particular, the excitation sources of background Earth’s free oscillations are discussed; the mechanisms of influence of stratified turbulence to the formation of the atmospheric boundary layer electric state and the variability of electric parameters are observed. The results of a modeling of a global ocean general circulation model with regional high resolution in the Strait of Gibraltar are analyzed. The results of numerical modeling of the integrated water circulation of the South China under the influence of southern tropical cyclone are given. The data of the large experiment on currents measurement in the Aniva Gulf are studied. A short-term variability of the temperature field in the White Sea is studied based on the experimental data. Based on numerical methods the hydrodynamic and hydroacoustic characteristics of the oscillating wings as the major structural element of the fin propulsor are determined. The algorithms of a restoration of sound speed vertical distribution while sounding from the ship are observed. The passive and active sonar optimal frequency is investigated taking in account all the influencing factors.