Assessment of Pollution of the Kerch Strait and Adjacent Black Sea Area Based on Field Measurements of 2019–2020

Oceanology - The paper presents the results of an analysis of the main pollutants (heavy metals, pesticides, detergents, hydrocarbons) in water, suspended particulate matter, and bottom sediments,...     

Concentration and Isotopic and Elemental Composition of Organic Matter in Subsea Thawed and Permafrost Deposits of Buor-Khaya Bay

Oceanology - A comparative analysis of the content and composition of organic matter (OM) in samples of bottom sediments and subaqueous permafrost rocks by the concentration of organic carbon (OC),...     

Geophysical Studies of the Seymour Sewell Seamount on the Flank of the Central Indian Ridge

Oceanology - The volcanic structure of the Seymour Sewell seamount appears to have formed over a relatively long time in at least two stages. Its main massif was formed as a result of volcanic...     

Spatiotemporal Variations in the Content of Pollutants in the Moscow Air Basin and Their Emissions

Izvestiya, Atmospheric and Oceanic Physics - The location of Moscow on a plain within higher latitudes when compared to other megacities creates conditions for the chemical transformation of...     

Relationship between Anomalies of the Rate of Snow Cover Formation in Western Siberia and Atmospheric Dynamics in the Northern Hemisphere in the Autumn–Winter Season

Izvestiya, Atmospheric and Oceanic Physics - The relationship between the anomalies of the intensity of snow cover formation in Western Siberia (WS) and thermodynamic state of the atmosphere of...     

A predictive numerical model for potential mapping of the gas hydrate stability zone in the Gulf of Cadiz

This paper presents a computational model for mapping the regional 3D distribution in which seafloor gas hydrates would be stable, that is carried out in a Geographical Information System (GIS) environment. The construction of the model is comprised of three primary steps, namely: (1) the construction of surfaces for the various variables based on available 3D data (seafloor temperature, geothermal gradient and depth-pressure); (2) the calculation of the gas function equilibrium functions for the various hydrocarbon compositions reported from hydrate and sediment samples; and (3) the calculation of the thickness of the hydrate stability zone. The solution is based on a transcendental function, which is solved iteratively in a GIS environment.The model has been applied in the northernmost continental slope of the Gulf of Cadiz, an area where an abundant supply for hydrate formation, such as extensive hydrocarbon seeps, diapirs and fault structures, is combined with deep undercurrents and a complex seafloor morphology. In the Gulf of Cadiz, the model depicts the distribution of the base of the gas hydrate stability zone for both biogenic and thermogenic gas compositions, and explains the geometry and distribution of geological structures derived from gas venting in the Tasyo Field (Gulf of Cadiz) and the generation of BSR levels on the upper continental slope.     

对虾传染性肌肉坏死病研究进展

对虾传染性肌肉坏死病(infectious myonecrosis,IMN)最初于2002年8月爆发于巴西Piaui州的凡纳滨对虾(Litopenaeus vannamei)养殖场,并很快在巴西东北沿岸蔓延开来,目前已传至亚洲.2004年,经美国亚利桑那大学(University of Arizona)水产病害实验室研究,该病为一种新的对虾疾病,根据其症状,暂定名为传染性肌肉坏死病.     

Two-dimensional analysis of the semidiurnal tide in some regions of the white sea

An improved method of two-dimensional kinematical structural analysis of tides (the “method of the orbits”) is presented. This method allows us to determine the parameters of the primary tidal waves shaping the observed tidal structure. The construction of the vertical orbits for the individual tidal harmonics is performed along the horizontal coordinate axes; one of them is oriented along the so-called “reactive azimuth,” which coincides with the direction of the tidal current at the instant of the zero tidal level. In this case, the orbit parameters include information on the amplitude-phase relations of the interfering waves and allow us to determine the angle of the waves crossing. The suggested method enables us to quantitatively describe the mechanism of the tidal formation with oblique interference both close to the shore and in the open sea. We tested the new method in two local zones of the White Sea (Morzhovets Island and in the vicinity of the entrance to Kandalaksha Gulf) where the presence of rotating semidiurnal tidal currents evidences the significant role of oblique interference of tidal waves. In these zones, the developed method made it possible to perform a detailed quantitative analysis of the local tide structure caused by the M₂ tidal wave, which plays the dominant role in the White Sea. The result describes the structure of the propagation of the primary tidal waves better than the field of “pure” energy fluxes that was used earlier.     

Validating and assessing the sensitivity of the climate model with an ocean general circulation model developed at the Institute of Atmospheric Physics,Russian Academy of Sciences

A new version of the Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS), climate model (CM) has been developed using an ocean general circulation model instead of the statistical-dynamical ocean model applied in the previous version. The spatial resolution of the new ocean model is 3° in latitude and 5° in longitude, with 25 unevenly spaced vertical levels. In the previous version of the oceanic model, as in the atmospheric model, the horizontal resolution was 4.5° in latitude and 6° in longitude, with four vertical levels (the upper quasi-homogeneous layer, seasonal thermocline, abyssal ocean, and bottom friction layer). There is no correction for the heat and momentum fluxes between the atmosphere and ocean in the new version of the IAP RAS CM. Numerical experiments with the IAP RAS CM have been performed under current initial and boundary conditions, as well as with an increasing concentration of atmospheric carbon dioxide. The main simulated atmospheric and oceanic fields agree quite well with observational data. The new version’s equilibrium temperature sensitivity to atmospheric CO₂ doubling was found to be 2.9 K. This value lies in the mid-range of estimates (2–4.5 K) obtained from simulations with state-of-the-art models of different complexities.     

The spectral characteristics and kinematics of short-period internal waves on the Hawaiian shelf

Based on the results of analyzing the characteristics of currents and temperature measured in the water space of the Mamala Bay (the Island of Oahu, Hawaii), we investigate the main properties of the field of short-period internal waves, which is very complex. We focus on analyzing the spectral characteristics and orbit parameters for waves with a period of 20 minutes. The results of investigations reveal two types of short-period internal waves for this area: intense and fast waves propagating predominantly toward the ocean and weaker and slower waves propagating mainly toward the coast. Suppositions are made on how these waves form: the strong and fast waves are likely to be caused by the decay of locally generated internal tides near the shelf edge, while the weak and slow and very short waves seem to result from the specific interaction between the pycnocline and strong tidal currents over a steep slope.