Search

The article describes the design and operational principles of the MDS-II bottom multimodem station, located in the coastal zone (depth of location 25 m) of the northeastern Black Sea at the Gelendzhik test site of the Shirshov Institute of Oceanology, Russian Academy of Sciences. The station is connected to the coastal center by a bottom fiber optic cable, through which power is supplied to the station, and online transmission of measurement data takes place. The station is an underwater server to which one can connect a measuring device and get a real-time access to it, as well as remotely control on its operation. The design of an automatic stationary station for vertical sounding (SSVS) of the water column, which is also used at the Gelendzhik test site, is described as well. This station is moored close to the MDS-II multimodem station and is connected to one of its modems. The station consists of a bottom electric winch installed on the seabed and a floating module (probe) on a cable line wound around the winch drum. When the command "sounding" is given, the cable unwinds and the floating module, equipped with temperature and pressure sensors, floats and measures the water temperature profile from the bottom layer to the sea surface. Then the cable is wound on a drum, and the floating module returns to the bottom layer. A prototype of a new SSVS is being developed, which will allow sounding of the water layer with a thickness of up to 100 m. It will be equipped with a multiparameter probe that makes joint measurements of hydrophysical and biooptical parameters. [ABSTRACT FROM AUTHOR]

The results of seismoacoustic studies carried out in the years 2020–2023 on the shelf of southeastern Crimea by employees of the Shirshov Institute of Oceanology, Russian Academy of Sciences, using an original complex of technical means, including seismoacoustic and acoustic profilers are discussed. The data obtained made it possible to clarify the position of the paleo valleys and to provide a seismostratigraphic reference of the reflecting horizons with the identification of the main seismic complexes in the Pleistocene–Holocene part of the section. Seismic facies analysis of the wave field made it possible to clarify the paleogeographic conditions for the formation of paleo valleys. [ABSTRACT FROM AUTHOR]

The use of towed underwater unmanned vehicles equipped with photo, video, and sonar systems has proven its effectiveness in studying the seafloor surface in integrated research of the World Ocean. This class of devices solves a wide range of tasks, including biological studies of benthic fauna and surveys of underwater technogenic objects. The towed vehicle "Videomodule" was developed at the Shirshov Institute of Oceanology, Russian Academy of Sciences, and has been successfully employed for such surveys for several years. The paper discusses the technical features and application issues of working with the "Videomodule." [ABSTRACT FROM AUTHOR]

Results of numerical experiments on the assimilation of in situ temperature and salinity profiles observed in the region of Drake Passage (the South Atlantic) during the expedition of Shirshov Institute of Oceanology of Russian Academy of Sciences (RAS) in the autumn of 2011 into the INMOM model developed by Marchuk Institute of Numerical Mathematics of RAS are considered. The previously developed method of assimilation presented in several publications is used. As a result of some experiments, it has been shown that the structure of the anticyclonic circulation associated with the Brazil-Malvinas Confluence in the area of the Argentine Basin has been mostly affected by the expedition data assimilation. Assimilated fields of ocean temperature on the surface and at various horizons show better agreement with reanalysis data than corresponding fields without assimilation. It is also demonstrated that the influence of assimilation spreads much further beyond the local area of observations and leads to changing all calculated characteristics (not only observed ones). [ABSTRACT FROM AUTHOR]

The article presents brief results of expeditionary studies of the Southeastern Baltic Sea and eastern Gulf of Finland during cruise 53 of the R/V Akademik Boris Petrov (2023). The expedition was a continuation of longstanding oceanological research conducted by the Atlantic Branch of the Shirshov Institute of Oceanology, Russian Academy of Sciences. Integrated geological, geophysical, hydrological, hydrochemical, hydrobiological, and geoecological research was carried out. New data on the state and dynamic of natural systems of the Baltic Sea were obtained. [ABSTRACT FROM AUTHOR]

The main goal of the work is to study the spatiotemporal structure of sea currents in the shelf–slope zone of the northeastern part of the Black Sea. The studies were carried out by numerical simulation methods using the combined hydrodynamic and spectral wave models incorporated in the DHI MIKE computational complex. The model has been verified based on the data of field observations performed by means of the hydrophysical test site of the Institute of Oceanology, Russian Academy of Sciences (Gelendzhik test site). As a result of calculations with a discreteness of half an hour, the fields of velocities and directions of currents for the period from January 2016 to December 2020 were obtained. Despite the fact that the total length of the massif is insufficient for climatic generalizations, analysis of the data obtained from the numerical experiment makes it possible to judge some general features of the seasonal dynamics of waters. As a result of the work that was carried out, the features of current velocity fluctuations in the frequency domain were revealed, and, based on the averaged current fields, the main seasonal features of water circulation in the shelf zone of the northeastern Black Sea coast were estimated. [ABSTRACT FROM AUTHOR]

The study considers the formulation of the problem and performs a numerical experiment for a short-term forecast of hydrological parameters using the data of two thermohaline surveys on September 14 and 16, 2019, at the test site of the Southern Branch of the Shirshov Institute of Oceanology, Russian Academy of Sciences (IO RAS) at Gelendzhik. Due to the small spatial scale of the survey area (about 15 × 15 km), a forecast as a solution to the Cauchy problem is impossible due to the large time gap between surveys. Therefore, the authors attempted to solve the forecast problem using the technique of a priori nonadiabatic sources, reflecting the temporal variability of the sought characteristics contained in the field data of the first survey. Essentially, this technique assumes a persistent trend of temporal variability of hydrological processes during the transition to the second survey. In this case, the problem of forecasting with nonadiabatic sources is divided into two stages using a quasi-hyperbolic system of equations. At the first stage, the problem of analysis with assimilation of the first survey data is considered, in the solution of which the required nonadiabatic sources are found. At the second stage, the forecast problem is solved by calculating nonadiabatic a priori sources. Comparison of the forecast results with the data of the second survey in this case yields satisfactory results. [ABSTRACT FROM AUTHOR]