В рамках исследования структуры циркуляции Черного моря на глубинах ниже главного пикноклина представлены данные о преобладающих направлениях, изменчивости и скорости течений. Данные о вертикальных профилях течений были получены контактными методами в ходе экспедиционных работ Морского гидрофизического института. Для исследования глубинных течений были выбраны 25 станций, которые содержали измерения на горизонте 500 м и более. Приводятся характеристики приборов и географическое расположение станций. Периоды зондирований на станциях варьировали в пределах от нескольких часов до двух месяцев. Обеспеченность данными как по времени, так и по пространству существенно неравномерна, однако в работе впервые описан и проанализирован полный массив измерений глубоководных течений начиная с 1960 года. После оценки качества данных и приведения к горизонтам 500, 750 и 1000 м сформирована таблица, демонстрирующая обеспеченность, повторяемость направления и средние оценки скоростей течений. Анализ вертикальных профилей показал, что векторы скорости течений на некоторых станциях в приповерхностном и глубинных слоях имеют близкие направления. Однако на большинстве из рассмотренных профилей направления скорости на разных горизонтах существенно отличаются. Для каждой станции и каждого горизонта были построены и проанализированы диаграммы направлений и модуля скорости течений, они использованы для иллюстрации случаев разворота течений на разных горизонтах. Абсолютная величина вектора скорости на горизонтах глубже 500 м может превышать значение в вышележащих слоях.

Combination of altimetry-based method of eddy identification and historical hydrological measurements for 1992-2015 is used to analyze the thermohaline and dynamic structure of the Black Sea eddies and its relation with eddy intensity, eddy age and season of a year. Anticyclonic eddies (AEs) are characterized by negative salinity anomalies, which can reach -1.7 psu at the depth of the main halocline. The temperature anomalies are positive in their upper layers, and negative in the deeper layers, because of the vertical displacement of the waters of the Cold Intermediate Layer (CIL). Cyclonic eddies (CEs) have the opposite structure with increased salinity, colder upper layers and warmer deeper layers. Thermohaline anomalies in the eddies of both signs are maximal in summer, while in winter they are shallowest and minimal. The displacement of pycnocline in eddies causes the decrease/increase of stratification in the upper layer of AEs/CEs and opposite increase/decrease in their deeper layers. It also causes the deepening/uplift of the layer of maximum geostrophic vertical shear in AEs/CEs. The latter is the probable reason of the observed higher intensity and deeper penetration of orbital velocities in AEs than in CEs. The changes of isopycnals positions during the eddies' lifetime are used to quantify the evolution of vertical velocity in AEs and CEs. In the beginning of AEs life during intensification phase, vertical velocity is directed downward, while during the decaying phase it change its sign and is directed upward. The opposite is observed in CEs. Vertical velocity is maximal at the pycnocline depth of 100-110 m with values changing from (- 8 to 8)* 10(-6) m/s in AEs, and from (+ 5 to -25)10(-6) m/s in CEs. Eddies thermohaline structure and altimetry-derived orbital velocity is tightly related. This relation obtained in the study and altimetry-derived data an the distribution of eddy frequency, translational speed and orbital velocity is used to quantify eddies salt, heat content and transport in the basin. The transport velocity of water in the eddies core (2-4 cm/s) is significantly smaller than the average velocity of the large-scale currents (similar to 10-40 cm/s). Such slowing causes the "relative" transport of eddies against the mean flow direction. This effect leads to the accumulation of brackish and cold water in the deep layers of east Black Sea and maintain the observed east-west asymmetry of the basin thermohaline fields.

External oceanographic conditions rather than anthropogenic influence are shown to cause the 3-dimensional distribution of anthropogenic microparticles (MP, 0.5-5 mm) within the body of sandy beaches of a non-tidal sea with strong wind/wave climate and seasonal sea level variations (the Baltic Sea). A patchy structure is confirmed in all three dimensions, with background concentrations of several tens of MP items per kg of dry sample weight versus peaking spots with several hundreds of items per kg dry weight. The background MP concentrations are of the same order of magnitude for the beach surface, beach body, and sands of underwater coastal slopes, highlighting that the contaminated by MPs sand cover of the entire sea coastal zone is one single entity, repeatedly re-distributed between its underwater and beach parts by every next storm. Peaking concentrations are related to stormy events and places with stronger water dynamics, and are associated with locations of coarser sands within the beach body and wracklines at the beach surface. This suggests that marine waters are the source of anthropogenic microparticles for the beach, and not vice versa. The prevalence of wave-driven overwind-driven beaching mechanism for MPs extracted from the beach samples is confirmed by the flotation tests. Size distribution of the extracted MPs is found to be similar to that obtained for plastics floating at the ocean surface. Such a coherency for different oceanic environments speaks in favor of independence of general fragmentation processes on the particular external conditions, shifting the attention to the fragmentation process and material properties of synthetic particles in marine environment. Capsule: Stormy winds, surface waves, and sea level variations rather than anthropogenic load define 3-d variability of pollution by synthetic microparticles within the sand body of beaches. (C) 2018 Elsevier B.V. All rights reserved.

The parameters of barotropic and baroclinic oscillations in the subinertial range have been obtained by numerical simulations of the Black Sea circulation using a model developed at the Marchuk Institute of Numerical Mathematics, Russian Academy of Sciences. The structures and periods of barotropic and baroclinic seiches are in good agreement with the known theoretical predictions and results of numerical modeling of seiches obtained for the Black Sea subbasins.

The transition from winter vertical mixing to the formation of the spring thermocline in the southeastern Baltic Sea is studied based on data from the hydrophysical measurements program (11 expeditions) in the Russian part of Gdansk Bay in March–June 2010, 2011, and 2013. CTD measurements were taken along the standard 18-km transect across the isobaths with a 500-m step abeam the city of Baltiysk. A set of frequently measured data was collected in a 1–2 week interval from the end of March to the beginning of May, which made it possible to analyze the transformation of the vertical thermal structure of water from inverse winter type to the summer stratification with the transition of temperature over the temperature of the density maximum. Series of repeated measurements at the deep and coastal stations as well as surface and subsurface towed measurements were carried out. The fact that lenses of freshened warmer water appear at the surface almost simultaneously with intensification of cold intrusions in intermediate (10–40 m) layers makes it possible not only to confirm the advective nature of the formation of the spring thermocline in the Baltic Sea, but also to hypothesize about the intensification of intrabasin exchange when winter-time vertical mixing ceases: the potential energy excess supported by vertical mixing in the 60-m upper quasi-homogeneous layer (UQL) of the Baltic Proper, in which the horizontal estuarine salinity gradient is significant, is converted to kinetic energy of exchange currents as the mixing process terminates. Such water dynamics makes it possible to explain the intensification of intrusions in the Baltic in spring and the formation of the cold intermediate layer due to the fast propagation of late-winter UQL water from the Bornholm Basin to the Baltic Proper. The results agree well with earlier published studies of other authors.

The Black Sea shelf is a region of intense manifestation of various dynamical processes. Under the influence of different natural forces, eddy-wave phenomena develop here, which influence the general circulation of sea waters, biological productivity, and the condition of the engineering structures. Modern numerical models allow us to simulate and analyze the processes of the joint dynamics of marine circulation and large-scale waves. In this work, we study the spatiotemporal spectral characteristics of the sea level and velocity fluctuations formed due to atmospheric forcing and tidal potential. The hydrophysical fields are calculated using the Institute of Numerical Mathematics, Russian Academy of Sciences (INM RAS), σ model based on primitive equations. We use the CORE data as atmospheric forcing at the sea surface; the tidal potential is described by the semidiurnal lunar constituent M2. Analyzing the simulation results makes it possible to emphasize that accounting for the semidiurnal tidal potential not only improves the accuracy of the sea-level calculation at coastal stations, but also generates subinertial baroclinic oscillations previously found in the Black Sea from the data of in situ observations.

Considering scarce available data on the velocity field in the deep layers of the Black Sea, it is important to contribute by deriving the velocity vectors from indirect sources.The Lagrangian velocity vectors of the Black Sea currents on the depths below the main pycnocline are calculated using the data on the trajectories and actual profile depths of the Argo profiling drifters in 2005-2015.The values and directions of the calculated vectors in the layers 350 -600, 600 -800, 800 -1200 and 1200 -1600 m are analyzed.The obtained results are statistically evaluated.It is shown that the prevailing number (88%) of the modules of the calculated current velocity vectors is within the range 1 -20 cm/s.The currents' velocity average for the whole period of measurements, is about 4 cm/s in the layers 350 -600 and 600 -800 m, approximately 6 cm/s in the 800 -1200 m layer and 3.5 cm/s in the 1200 -1600 m layer.The mean current velocities from the whole data access are higher in January -March, whereas the lowest ones fall on June -October.On the background of general cyclonic circulation the meso-scale eddy structures on the specified depths are revealed.A discussion is presented on the available approaches to increase the precision and credibility of the obtained velocities magnitude and direction.

Subinertial waves at the Black Sea shelf have been thoroughly studied in the last decades from the theoretical, observational and experimental points of view. Results of numerical prognostic experiments on modeling of the Black Sea circulation based on thermo-hydrodynamic eddy-resolving MHI model are studied. Spectral peaks in the oscillations of the current velocity component vector, temperature, salinity and vertical velocity are identified for the selected stations by means of the Fourier spectral analysis. The obtained energy-transporting oscillations are interpreted using expert estimates and comparison with the previous research. Time range of numerical calculation is conditioned by availability of data on the mass and energy external flows (reanalysis of the atmosphere state). Hydrodynamic parameters for April, 2006 and May - September, 2013 are considered. It is noted that seasonal variability of stratification and the model high sensitivity to the wind effects condition spectral characteristics of the wave processes on sub-inertial scales and intensity of mixing of the upper mixed layer. Two main energy-carrying intervals where the oscillations are confidently reconstructed by the modelare pointed out: large-scale relatively slow movements with the periods from 4 to 7 days and short-period waves with the periods from 10 to 40 hours. Due to relatively smooth bathymetry, origins of the short-period oscillations are hard to trace.

BACKGROUND:Previously we have shown that, during sleep, electrical and magnetic stimulation of areas of the stomach and small intestine evoked neuronal and EEG responses in various cortical areas. In this study we wanted to correlate natural myoelectrical activity of the duodenum with cortical neuronal activity, and to investigate whether there is a causal link between them during periods of slow-wave sleep.METHODS:We have recorded the myoelectrical activity from the wall of the duodenum and activity of single neurons from three cortical visual areas in naturally sleeping cats and investigated causal interrelationship between these structures during slow-wave sleep.KEY RESULTS:About 30% of the cortical neurons studied changed their firing rate dependent on the phases of the peristaltic cycle and demonstrated selectivity to particular pattern of duodenal myoelectrical activity during slow-wave sleep. This interrelationship was never seen when awake.CONCLUSIONS & INFERENCES:This observation supports the hypothesis that, during sleep, the cerebral cortex switches from processing of exteroceptive and proprioceptive information to processing of interoceptive information.

A three-dimensional numerical model of the pollution of the water column and bottom sediments of the Black Sea by polychlorobiphenyls (PCBs) is developed. The model consists of a physically complete hydrodynamic block and also the transport and transformation modules for the detritus and PCB. The PCB transfer module calculates three functions: the concentration of dissolved PCB, the PCB on sinking detritus particles and in the upper layer of the bottom sediments. We take into account the processes of adsorption-desorption of PCB on sinking detritus particles, the alternating-sign flow of the substance on the water-sediment boundary, and destruction of the detritus. A model spin-up calculation is performed for the scenario of an instantaneous PCB emission from the Sfantu Gheorghe branch of the Danube. It is shown that the PCB transport on detritus is a natural buffer mechanism damping the spread of a steady organochlorine pollution.

The localization and morphological features of viscerosensory neurons of sacral spinal ganglia (SSG), innervating the colon, were investigated. In urethane anaesthetized cats, the solution of horseradish peroxidase was injected under the serosa of ascending and descending parts of the colon as well as of the rectum. After 48 hours animals were repeatedly anesthetized and transcardially perfused. Sections of SSG were stained according to Mezulam protocol (1978). All the regions of the colon studied were shown to receive afferent innervation from neurons of SSG SI, SII and SIII. Maximum number of the labeled cells was detected in SSG SII. The intensity of afferent innervation of the colon by the neurons of SSG was found to increase along its length in cranio-caudal direction.