Use of a problem-oriented database for statistical analysis of the hydrochemical characteristics of the redox layer of the Black Sea     

O. I. Podymov 《Oceanology》2008,48(5):656-663

A problem-oriented database (PODB) was developed for the statistical analysis of the hydrochemical characteristics of the redox layer of the Black Sea. The paper describes the features of the PODB, including the algorithm of interpolation and the location of the levels of the appearance and disappearance of hydrochemical parameters (the so-called onset levels) based on Akima’s spline. The application of the PODB allowed us to obtain a series of biogeochemical estimates, in particular, (1) to reveal the constancy of the vertical gradients of the hydrochemical parameters at selected density levels; (2) to calculate the seasonal variability of the degree of manifestation of the phosphate minimum in the near-shore and open sea areas; and (3) to calculate the interannual variability of the level of the disappearance of the hydrogen sulfide, ammonium, total manganese, and methane, as well as the oxygen content in the cold intermediate layer, and to find out their relations with the climatic variations.  相似文献   

Seasonal evolution of the mediterranean water propagation in the north Atlantic     

B. N. Filyushkin  S. N. Moshonkin  N. G. Kozhelupova 《Oceanology》2008,48(6):771-779

The Climatic variability of the seasonal water exchange in the Strait of Gibraltar and the spatial structure of the tongue of the Mediterranean Waters (MW) in the Atlantic Ocean are studied. The analysis is based on the results of a numerical experiment using a 3D ocean circulation model developed at the Institute of Computational Mathematics (ICM RAS) with a resolution of the dataset over the latitude and longitude equal to 0.25 degree. The seasonal evolution of the salinity and density fields is calculated in the North Atlantic (from 20 °S, including the Mediterranean Sea) and in the Arctic Ocean (including the Bering Sea). The comparison of the model estimates with the results of field observations demonstrated good agreement. The transport of the MW into the Atlantic is close to the observed data (during the year, it varies from 1.8 Sv in the winter to 0.9 Sv in the summer). The complex pattern of the currents in the region of the MW spreading is confirmed. The alternating character of the saline MW tongue at the 1000-m level is shown for the first time. It is found that the zones of maximum salinities in the open part of the ocean coincide with the main trajectories of migration of MW lenses and the regions of their decomposition.  相似文献   

Cretaceous-Paleogene back-arc basins in the Iran-Afghanistan-Pamirs segment of the Eurasian active margin     

V. G. Kaz’min  N. F. Tikhonova 《Doklady Earth Sciences》2008,422(1):1018-1020

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Possibility to determine parameters of seismic waves from the results of electric field measurements on the ocean floor     

B. A. Burov 《Doklady Earth Sciences》2008,419(2):444-447

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Hydrological changes in the White Sea during the historical period inferred from analysis of dinocysts     

E. A. Novichkova  E. I. Polyakova 《Doklady Earth Sciences》2008,423(1):1290-1293

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Mineralogy of morphogenetic types of ferromanganese deposits in the world ocean     

O. Yu. Bogdanova  A. I. Gorshkov  G. V. Novikov  Yu. A. Bogdanov 《Geology of Ore Deposits》2008,50(6):462-469

The mineralogy and structural features of the main types of ferromanganese deposits—nodules, micronodules, Co-bearing crusts, crustlike nodules, and low-temperature hydrothermal manganese crusts and ferruginous ochers—are considered. The correlation between their mineral composition and structure is shown. The proposed classification of mineral types is based on characteristic assemblages of Fe and Mn minerals.  相似文献   

On the reliability of millennial reconstructions of variations in surface air temperature in the Northern Hemisphere     

N. M. Datsenko  D. M. Sonechkin 《Izvestiya Atmospheric and Oceanic Physics》2008,44(6):739-744

The reliability of the recently published reconstructions of the surface air temperature variability in the Northern Hemisphere over the past 2000 yr is discussed. For this purpose, the power spectra of the two best known reconstructions (Mann et al.[10–12] and Moberg et al. [13]) are calculated and compared to the spectra of the 150-yr temperature series based on instrumental observations and simulated 1000-yr series. It is found that the Mann et al. reconstruction drastically underestimates low-frequency temperature variations, whereas the Moberg et al. reconstruction reproduces them much better, although with a certain underestimation rather than overestimation, as Mann et al. have recently argued.  相似文献   

Studies from the drifting ice station in April 2008     

I. A. Mel’nikov 《Oceanology》2008,48(6):888-890

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Budget of sediments and forecast of long-term coastal changes     

I. O. Leont’yev 《Oceanology》2008,48(3):428-437

A method for predicting the coast evolution based on the calculated estimates of the components of the sediment budget is discussed. The approaches outlined in a series of previous publications of the author [9, 10, 11] are further developed. The prerequisites and concepts used as the basis of the suggested method for forecasting are characterized. The sediment budget parameters under typical conditions are presented. The contributions of natural processes and the anthropogenic impact are compared. Different approaches for calculating the principal sediment budget components, including the cross-shore flux through the lower boundary of the coastal zone, the eolian flux of sand material through the upper limit of the coastal zone, and the alongshore sediment flux gradients, are considered. The examples of forecasting the development of coasts in the Baltic and Kara seas and the Sea of Okhotsk are given for the period from 100 to 500 years. The results obtained show that, in the case of a balanced budget of the sediments, the future behavior of the coast would be mainly governed by the variations in the sea level. This factor is capable of determining the changes in the coastline, whose recession and advancing would depend on the rate of the sea level rise. Under specific conditions, an enhanced sea level rise can trigger destructive processes (for example, the erosion of a coastal bar or the thermal abrasion of a cliff). In the case of a strong imbalance in the sediment budget, sea-level changes play a subordinate role.  相似文献   

Effects of particle migration on the features of their transport by tidal currents in a region of freshwater influence     

K. A. Korotenko  A. V. Sentchev 《Oceanology》2008,48(5):622-633

Using a combined model that couples a three-dimensional ocean circulation model, a model for tidal currents, and a model for particle transport, the structure of the velocity field of the tidal current and the transport of particles migrating over the vertical were studied in the zone of the influence of the riverine runoff in the eastern part of the English Channel. It was found that the interaction between the tidal current and the baroclinic flow formed by the riverine runoff off the northeastern coast of France generates a steady-state intensive (～0.3 m/s) residual current in the zone of the effect of the riverine runoff. In order to assess the influence of different types of particle migration (which simulate ichthyoplankton) on the processes of their transport in the region under consideration, we performed numerical experiments with particle clusters, for which parameterization of their migration was implemented on the basis of the field observations over the proper vertical movements of different types of ichthyoplankton. The experiments showed that the distribution of the fields of the particle concentrations and the velocities of their movements depend not only on the background hydrophysical conditions but also on the character of the vertical migration of the particles. In this paper, a comparison between the results of the modeling and those of the field observations in the region under consideration are presented.  相似文献