A theoretical study of the kinetics of the boric acid–borate equilibrium in seawater

Dissolved boron in seawater occurs mainly in the form of boric acid (B(OH)₃) and borate (B(OH)₄⁻). While the equilibrium properties of the dissociation of boric acid have been studied in detail, very little work has focused on the kinetics of the boric acid–borate equilibrium in seawater. Here, we present a theoretical study of the relaxation of the seawater borate–carbonate system towards equilibrium using the experimental data of Mallo et al. [Nouv. J. Chim. 8 (1984) 373] and Waton et al. [J. Phys. Chem. 88 (1984) 3301]. The reaction rate constants are two to four orders of magnitude smaller than typical rate constants of diffusion-controlled reactions of other acid–base equilibria. This is presumably due to the substantial structural change that is involved in the conversion from planar B(OH)₃ to tetrahedral B(OH)₄. The time required to establish the boric acid–borate equilibrium in seawater is calculated to be ∼95μs at temperature T=25°C and salinity S=35. Considering stable boron isotopes ¹¹B and ¹⁰B, the isotopic equilibration time is ∼125 μs. As a result, kinetic isotope effects during coprecipitation of boron in calcium carbonate are unlikely and therefore do not affect the use of stable boron isotopes as a paleo-pH recorder.     

Study of Adsorption Isotherm Curves of Amino Acids on the Kaolinite

This paper studies the adsorption isotherm curves of four amino acids (glyucine,aspartic acid,glutamic acid and lysine)and the effects of existences of different concentrations of Cu(Ⅱ) on them.Both the adsorption isotherm of the amino acids on the kaolinite and that when the copper ion Cu(Ⅱ） exists belong to the Langmuir type.The slopes of these adsorption isotherm increase with the increasing concentrations of Cu(Ⅱ） added.It can be explained in terms of formation of the type(Ⅰ） ternary surface complexes in these systems.The regular pattern of the effects of copper ion Cu(Ⅱ) on the adsorption isotherm of amino acids on the kaolinite is identical with that of its effects on the exchange and adsorption percentage E(%)-pH on the kaolinite in the same system.     

Submergence of the Sublittoral–Bathyal Species into the Abyssal Zone of the Sea of Japan

Oceanology - The bathymetric ranges of the same deep-sea (>2000 m) species in the Sea of Japan and outside it are compared. Among 85 deep-sea species of the Sea of Japan mega- and...     

Atmospheric effects of the gas–dust plume of the Chelyabinsk meteoroid of 2013

We have performed a simulation of the convectively induced ascent of the gas–dust cloud formed during the atmospheric passage and explosion of the Chelyabinsk meteoroid. The acceleration, velocity, and rise of the gas–dust cloud have been described as functions of time and altitude. The time of dust settling in the atmosphere has been estimated. The results of calculations are in a close agreement with the observational data.     

Development of the POLCOMS–WAM current–wave model

The continuous research and improvement of ocean modelling helps to provide a more sustainable development of coastal and offshore regions. This paper focuses on ocean modelling at the NW Mediterranean using the POLCOMS–WAM model with new developments. The Stokes’ drift effect on currents has been included and the distribution of surface stress between waves and currents has also been considered. The system is evaluated in the NW Mediterranean and an evaluation of different forcing terms is performed. The temperature and salinity distributions control the main patterns of the Mediterranean circulation. Currents are typically small and therefore the modification of waves due to the effect of currents is minimal. However, the wave induced currents, mainly caused by a modified wind drag due to waves, produce changes that become an important source of mass transport. POLCOMS was able to reproduce the main Mediterranean features, its coupling with WAM can be a very useful tool for ocean and wave modelling in the Mediterranean and other shelf seas.     

Physicochemical modeling of the behavior of microelements under the mixing of acid riverine water (the Yur’ev River) with seawater

By means of physicochemical modeling with the Selektor software package, models were created and calculated for acid riverine water (pH = 2.19), for seawater, and for the mixing of these types of waters. The Yur’ev River-Sea of Okhotsk system was assessed as an example. The physicochemical migration forms of microelements (aluminum, zinc, lead, iron, manganese, and silicon) and their behavior in the water-mixing zone were established. The formation of solid hydrogenous phases under the mixing of acid riverine waters with seawater was shown. By means of the MINTEQA2/PRODEFA2 software package, the influence of the sorption processes on the behavior of the elements considered in the mixing zone was revealed.     

Morphology and Structural Features of the Subduction Zone in the Vicinity of Kuril–Kamchatka–Aleutian Junction

Oceanology - The specific morphology of the inner and outer slopes of the eastern Kuril–Kamchatka Trench were revealed based on joint study of bathymetry and seismic profiles obtained in two...     

Peculiarities of the Rock–Fluid System of the Subduction Zone in the South Caspian Basin

Izvestiya, Atmospheric and Oceanic Physics - The goal of this study is to identify the properties of the rock–fluid system in the subduction zone of lithospheric plates using the example of...     

Model of the Dead Sea. Simulation of the Variability of the Thermohaline Water Structure in 1992–2000

Within the framework of the integral model in isopycnic coordinates including the upper mixed layer, we study the rearrangement of temperature and salinity fields in the Dead Sea. It is forced by the variability of atmospheric factors and mass fluxes through the lateral boundaries of the basin, which are connected with the freshwater run-off to the sea and the outflow from the sea to the shallow south bay, where evaporator installations for salt extraction are located. Such factors as solar radiation, wind velocity, air temperature, and relative humidity are prescribed. Evaporation is calculated with the use of a bulk formula, whereas precipitation intensity and discharge through the lateral boundaries are determined as functions of the sea level obtained from observations. This model reflects the specific character of the Dead Sea and takes into account the effect of water salinity on its evaporation, salt concretion, and mechanical evaporation. Comparison with the data of observations shows that the proposed model fairly precisely describes the observed specific features of the thermohaline water structure in the meromictic (1992–1996) and holomictic (1996–2000) periods.     

Dynamic–Stochastic Parametrization of Cloudiness in the General Circulation Model of the Atmosphere

Izvestiya, Atmospheric and Oceanic Physics - The method of Dynamic–Stochastic parametrization of the nonconvective cloud amount in the general circulation model of the atmosphere is...     

Effect of changes in the composition of seawater on the density–salinity relationship

Over the next 5–10 years, the WOCE hydrographic program will generate reliable hydrographic data for the world oceans. The resultant conductivity salinity, temperature, and pressure data will generate calculated densities that will be used to examine mixing along constant density surfaces. Changes in the composition of deep waters due to the breakdown of plant material can effect the calculated densities at a given conductivity salinity. The increases in SiO₂, nitrate, alkalinity, and TCO₂ (or pH) can change the density of seawater as well as the conductivity. For studies of the salinity and density fields over small spatial scales, these changes will be small, but for large scale and ocean to ocean studies the differences can be significant. The density calculations based on the salinity determined from conductivity need to be adjusted for the offsets due to changes in the composition of seawater. This report describes how this correction should be made using existing information.     

Calculation of electric conductivity of water of the Aral Sea and correction of the sound salinity of 2002–2009

The Aral Sea is an important water area both for monitoring and oceanological studies, because its salinity and salt composition strongly differ from the oceanic. We offer a semiempiric calculation method of electric conductivity and the coefficient of its temperature dependence k judging from the ionic composition of water. The properties of the solution are considered as the sum of properties of seven binary salts taken based on the ionic composition of the solution. The MgSO₄ concentration is thought to be the highest possible, which makes the salt concentration nearly unambiguous. In a salinity range of 46–120‰ and temperature range of 5–25°C (2002–2009), the standard deviation of the calculated and measured electric conductivity was 2.9%. To refine the calculation of salinity from electric conductivity measurements using the “oceanic” formula, we suggest its preliminary reduction to a constant temperature (20°C) using the measured or calculated coefficient k.     

Physical Modeling of Structure Formation at the Early Stages of the Iberia–Newfoundland Separation

Oceanology - The features of structure formation on the adjacent margins of Iberia and Newfoundland are considered based on an analysis of geological and geophysical data and physical modeling....     

Reflection of the State of Magmatic Matter and Seismotectonic Features of the Structure of the Avachinsky–Koryaksky and Dzenzur–Zhupanovsky Volcanic Groups of Kamchatka in Terms of Kinematic Parameter VP/VS

Izvestiya, Atmospheric and Oceanic Physics - For regional earthquakes, the kinematic parameter VP/VS, an analog of the TAU parameter, was analyzed in order to study the state of magmatic matter,...     

Two Modes of Atmosphere–Ocean Interaction in the Atlantic Sector of the Arctic Basin

Oceanology - The paper examines the influence of the main mode of interannual variability of the North Atlantic climate system—the North Atlantic Oscillation (NAO)—on the hydrophysical...     

Variability of the fields of concentration of microelements and strontium in seawater near the South Coast of the Crimea in 2002–2007

We study the space-and-time variability of the concentrations of 27 microelements (Sc, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Mo, Ag, Cd, Sn, Se, Sb, Ba, La, Ce, Sm, Eu, Tb, Hf, Hg, Pb, Au, Th, and U) and Sr in the sea, river, and waste waters of the South Coast of Crimea in 2002–2007. Parallel with the data about elements studied earlier, we present, for the first time, the data of investigations of the contents of rareearth elements (Lu, Nd and Yb) whose concentrations in the major part of the analyzed samples of seawater were lower than the limit of their quantitative determination. We present the ranges of the concentrations of elements and perform their comparison with the data of the previous period of monitoring.     

Dynamic Processes of the Arctic Stratosphere in the 2020–2021 Winter

Izvestiya, Atmospheric and Oceanic Physics - The Arctic stratosphere winter season of 2020–2021 was characterized by a weakened stratospheric polar vortex as a result of a major sudden...     

Investigation of the sensitivity of the Mellor–Yamada parametrization to the choice of finite-difference analogs in a numerical three-dimensional model of the operative prediction of currents in the black sea

Within the framework of the Mellor–Yamada approach, we realize a numerical scheme for the calculation of the coefficients of turbulent viscosity and diffusion in the z -system of coordinates for the three-dimensional model of operative prediction of currents in the Black Sea. Some discrete analogs of the equations for turbulent kinetic energy and turbulence macroscale are studied. Their high sensitivity to the choice of finite-difference approximations is demonstrated. On the basis of the comparison of the results of prognostic experiments with the data of observations, we choose the best approximation of the term used to describe the generation pf turbulence energy.     

Hydrometeorological characteristics of the Black-Sea region in the years with extreme values of the Sargasso–Black-Sea index

We analyze the annual average values and the anomalies of some hydrometeorological characteristics averaged over the period since January till March near the South Coast of Crimea and in the open part of the Black Sea. It is shown that the sea-surface temperature, the surface temperature of air, and the atmospheric precipitation in the Black-Sea region are lower than the climatic mean values for the extremely high values of the index of North-Atlantic Oscillation (NAO index) (NAO ≥ 1) and the surface temperature gradient between the Sargasso and Black Seas (SBS index) (SBS ≥ 1). In the years with NAO ≤ − 1 and SBS ≤ − 1, the indicated characteristics exceed the climatic mean values. The entire process of changes in the sign of anomalies of the hydrometeorological characteristics runs with a period close to 20 yr.