tri bu tion of Hy dro log i cal Pa ram e ters over the Meth ane Seep Site in the Golubaya Bay (the Black Sea): A Con nec tion with Sub ma rine Fresh wa ter Dis charge T. V. Malakhova*, I. N. Ivanova, A. A. Budnikov, A. I. Murashova, and L. V. Malakhova Kovalevsky In sti tute of Bi ol ogy of the South ern Seas, Rus sian Acad emy of Sci ences, pr. Nakhimova 2, Sevastopol, 299011 Rus sia Lomonosov Mos cow State Uni ver sity, GSP-1, Leninskie Gory, Mos cow, 119991 Rus sia

Concentrations of methane (CH4) in marine water of the Sevastopol Bay were measured during different seasons of 2017–2018 and its emissions from water to the atmosphere were calculated. The CH4 content in water was measured by headspace method using the HP 5890 gas chromatograph. The CH4 surface concentration varied over a wide range, from 2 to 210 nmol L–1, and the CH4 saturation level was 61 to 6814% as compared to the equilibrium values. It was found that CH4 concentration depends on the season. The lowest values were found in June, and the highest in November. The water of Sevastopol Bay appeared to be a source of CH4 for the atmosphere during the whole period of survey averaging from 17 to 112 µmol m–2 a day. The estimated time of dissolved methane emission turnover in the Sevastopol Bay ranges from 12 to 37 days.

Internal waves on the Black Sea shelf are analyzed using in situ data. Inertial waves with different mechanisms of generation are identified. The phase velocity of short-period internal waves is estimated. Internal waves of the second barocline mode, whose mechanism of generation is probably determined by the decay of inertial waves, are observed. The existence of a train of second-mode internal waves is shown.

This study provides new data on the strontium distribution and behavior in groundwater from the Permian aquifer system, which is used for public water supply in the Velsk region of Arkhangelsk District. We used data from recent sampling of groundwater and host rocks as well as data from previous studies over the last 25 years. Measurements of exchangeable cations obtained in this study will be used in the further thermodynamic calculations and experimental observations.

The air-flow velocity field near the water surface is studied in the zone of wind-wave intensification. Caused by a periodic separation of eddies, a nonzero time-averaged value of the wind velocity in the near-water streamline is detected at the leading slope of the wave. The distribution of pressure along the wave with allowance for the vertical velocity shear and disturbances produced by eddies and a periodic deceleration of the viscous layer was calculated with the aid of the Cauchy-Lagrange integral. This procedure made it possible to calculate the growth rate of the wave amplitude, whose value was found to be close to its experimental value at the initial stage of acceleration.

A laboratory study of the wind-driven surface-water current under no-wave conditions provided by uniform or accelerated stationary motion of air under an oblique cover is conducted. The dependence of drift velocity on wind velocity is obtained. It is shown that the ratio of these velocities is governed by the temperar lures of the media and by the ratio of the surface-layer thickness of air with a linear vertical profile of velocity to the thickness of that layer in water. The dependence of the thickness of these layers on the wind velocity is obtained for a steady-state current.

Results of laboratory experimental studies of the effect of turbulence on the vertical velocity of solid particles in water suspension are presented. The rate of particles settling has been found to decelerate significantly. These particles consume a part of turbulent energy, its amount largely depending on the size of particles themselves and the intensity of turbulence.

The effect of suspended particles of different sizes on turbulence was studied in a laboratory facility with a lattice oscillating in a liquid. The measurements were conducted in both fresh and salt water as well as in suspension for different values of the lattice oscillation frequency. Energy exchange was found to occur in the turbulized finely dispersed suspension, which results in the transfer of a part of turbulent energy to solid particles. The particle settling rate gets smaller than the Stokes value, and the level of this decrease depends on the turbulence parameters and particle sizes. As a result, the lifetime of suspended particles increases, which considerably affects the distance of particle transport by liquid flows.

Statistical analysis of total ozone and its vertical distribution was carried out on the base of data obtained by rocket soundings with the aim to reveal influence of solar activity. The coherence between monthly mean total ozone data series for six latitudinal zones in the Northern Hemisphere and solar spots has weak: but steaby maxima for 9 and 13 - 15 years periods of oscillations. The value of coherence does not exceed 0.15 and growth to the higher latitudes. The analysis of ozone profiles for middle latitudes reveales the decrease in ozone concentration between 30 - 50 km for winter and increase for autumn. High correlation between disturbances of ozone content in two points (Voeykovo, Petropavlovsk) after strong geomagnetic events was also revealed.

The adsorption of seven nonionic surface-active substances (NSAS) by polyamide yarn has been studied in the temperature range 25–55°C.

Defects in the scheme for passing yarns through the plastic rolls on the fibre-guide bars on KO-228-IM2 twisting machines have been noted.

The possibility of using the polarographic method to investigate the adsorption of nonionic surface-active substances by the surface of polyamide fibres has been demonstrated.

In a Teprém-6 emulsion medium, St3 steel with a chromium coating which has an assigned micro-relief is more corrosion-resistant than the alloyed steel 9Kh18.