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.

Herein we provide information on the integrated geological, geophysical, sedimentological, paleoceanographic, hydrophysical and biological investigations in the Central Atlantic during the cruise 45 of the R/V "Akademik Nikolaj Strakhov" in October-November 2019. The preliminary scientific results are discussed.

—In 2019, a new instrument was included in the multifunctional measuring complex at the Gelendzhik Research Site (Shirshov Institute of Oceanology, Russian Academy of Sciences, IO RAS), which allows automatic measurement of the hydrophysical parameters of the aquatic environment from the bottom layer to the surface of the waterbody with on-line transfer of data to the coastal center. This is a stationary station that uses a bottom winch for automatic vertical profiling of natural waterbodies. The model of the station was developed in 2018. It measures temperature profiles with temperature and pressure sensors located in a streamlined body: a carrier that moves according to a programmed algorithm. The carrier has positive buoyancy and is connected by a thin strong coaxial cable to the station’s bottom unit. The bottom unit includes a winch and electronic control units. The cable provides power to the carrier sensors and transmission and recording of measurement data in the station’s solid-state memory. Parameter measurements with a fine-structure vertical resolution are carried out with probes moving up and down. The data obtained are transmitted via a fiber-optic cable laid along the sea bottom to the coastal center located at the end of the pier of the Southern Branch of IO RAS. This cable also supplies the station with power. The first results demonstrated the qualitatively new possibilities of the station for measuring the parameters of the marine environment in the entire water column, including the near-surface layer.

Приведены сведения о комплексе геолого-геофизических, литолого-палеоокеанологических, гидрофизических и биологических исследований в Центральной Атлантике в 45-м рейсе НИС “Академик Николай Страхов” в октябре–ноябре 2019 г. Обсуждаются предварительные результаты экспедиции.

The article describes a technique for studying the spatiotemporal variability of the temperature of the water medium in the Black Sea shelf zone using a cluster of anchored temperature sensor chains (thermoresister chains). The cluster consists of three spaced thermoresister chains situated on the inner shelf of the northeastern Black Sea and operating as a part of the Gelendzhik Site of the Shirshov Institute of Oceanology, Russian Academy of Sciences (IO RAS). It is shown that the cluster makes it possible to effectively record the short-period spatiotemporal variability of the temperature field. The quantitative characteristics of this variability, as well as external factors determining it, are established. One of the factors is internal waves. The temperature variability can be used to determine the fluctuation amplitude, and recording these fluctuations at spaced thermoresistor chains makes it possible to find the velocity and propagation direction of internal waves. Some examples of recording trains of short-period internal waves are presented. Different methods are used to visualize the temporal variability of the vertical temperature distribution.

This model provides a periodic measurement of temperature profiles from the bottom layer to the water surface in a programmable mode using temperature and pressure sensors placed in a single streamlined body (probe). The probe is connected by a thin resistant cable to the bottom block of the station, including a winch and an electronic unit. This cable provides power to the probe sensors, and transmits data to the station’s solid-state memory. Initially, the cable is wound on the winch drum, and the probe is located near the bottom block of the station. The probe has positive buoyancy. When turning on the winch to unwind the cable, the probe starts to go up. After it reaches the water surface and stays there for a short time, the winch turns back, the cable is wound onto the drum, and the probe is pulled down until it reach the bottom block. Measurements of parameters are carried out when the probe moves up and down with fine-scale vertical resolution. During regular use of the station in the water area of the IO RAS Gelendzhik Research Site on the Black Sea, the measurement data will not only be recorded in the station’s memory, but also promptly transmitted to the coastal center via a cable laid across the sea floor. This cable will also provide power to the station. Preliminary laboratory and field tests of the main components of the station are conducted. In the developed version, the station is designed for long-term monitoring of the hydrological structure of the marine coastal zone in operative mode. It may be retrofitted with bio-optic and hydrochemical sensors for environmental monitoring of reservoirs, the depth of which does not exceed 50-100 m.

This model provides a periodic measurement of temperature profiles from the bottom layer to the water surface in a programmable mode using temperature and pressure sensors placed in a single streamlined body (probe). The probe is connected by a thin resistant cable to the bottom block of the station, including a winch and an electronic unit. This cable provides power to the probe sensors, and transmits data to the station’s solid-state memory. Initially, the cable is wound on the winch drum, and the probe is located near the bottom block of the station. The probe has positive buoyancy. When turning on the winch to unwind the cable, the probe starts to go up. After it reaches the water surface and stays there for a short time, the winch turns back, the cable is wound onto the drum, and the probe is pulled down until it reach the bottom block. Measurements of parameters are carried out when the probe moves up and down with fine-scale vertical resolution. During regular use of the station in the water area of the IO RAS Gelendzhik Research Site on the Black Sea, the measurement data will not only be recorded in the station’s memory, but also promptly transmitted to the coastal center via a cable laid across the sea floor. This cable will also provide power to the station. Preliminary laboratory and field tests of the main components of the station are conducted. In the developed version, the station is designed for long-term monitoring of the hydrological structure of the marine coastal zone in operative mode. It may be retrofitted with bio-optic and hydrochemical sensors for environmental monitoring of reservoirs, the depth of which does not exceed 50-100 m.