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1.
A. G. Zatsepin P. O. Zavialov V. V. Kremenetskiy S. G. Poyarkov D. M. Soloviev 《Oceanology》2010,50(5):657-667
An area of about 40000 km2 of desalinated upper layer waters with a salinity of less than 25 psu was found during cruise 54 of the R/V Akademik Mstislav Keldysh in the southwestern part of the Kara Sea (September 2007). Close to the boundary of this region located near the eastern
coast of Novaya Zemlya, the salinity was less than 16 psu. The thickness of the desalinated layer was about 10 m. The results
of the chemical analysis revealed that the observed desalination of the sea water was produced, first of all, by the Yenisei
River, while the contribution of the Ob River’s waters was secondary. However, the most desalinated region near the eastern
coast of Novaya Zemlya was separated from the Ob-Yenisei estuary and corresponded to a quasi-isolated lens. It is likely that
the formation of this lens, as well as the major part of the desalinated upper layer waters, occurred in June when the flood
of the Yenisei was maximal, while the further drift of the desalinated waters to the west of the Ob-Yenisei estuary was forced
by the prevailing northern wind. The additional desalination (by 2–3 psu and even more) of the upper layer waters near the
eastern coast of Novaya Zemlya might be related to the melting of the Novozemelskiy ice massif. The regularities of the temporal
evolution of the upper desalinated layer, as well as the influence of this layer on the hydrological structure and dynamics
of the southwestern Kara Sea, are discussed. 相似文献
2.
The report presents the results of hydrophysical and hydrochemical studies in Blagopoluchiya Bay (Novaya Zemlya Archipelago) based on data of integrated expeditions of the Institute of Oceanology in the Kara Sea in 2007, 2013, and 2014. The main focus was the influence of the Ob and Yenisei rivers, as well as of the runoff of meltwaters from the coasts of the archipelago on the hydrochemical and hydrophysical structures of the bay waters. The features of water exchange between the bay and adjacent aquatic area are considered, along with the renewal mechanisms for deep waters in the bay (deeper than 100 m). The possible occurrence of stagnant effects in deep layers of the bay is evaluated. 相似文献
3.
This report presents a new analysis of the results of two hydrochemical surveys over the Ob Bay in 2010 performed by the Institute of Fisheries and Oceanography (VNIRO) and the Institute of Oceanology (IO RAS). The unique world feature of the Ob River-Ob Bay system is shown. The water volume in the bay exceeds the average annual runoff of the Ob River, being somewhat under the total runoff of all the inflowing rivers. Because of this, the complete renovation of the waters in the bay requires a long time. The within-year distribution of the runoff is characterized by both the flood waters and those of the Ob River winter runoff characterized by much different hydrochemical parameters registered even in the course of summer surveys in the bay. This fact, but not the biological transformation of the waters, as assumed previously, is the primary cause of the variability of the water composition in the bay. The summer waters of the Ob River reach the sea-ward boundary of the bay only in the next spring, enter the Kara Sea with the spring flood, and form lenses of desalinated waters in the sea. The autumn expeditions by the IO RAS found that the waters in the lenses were quite similar to the autumn waters in the bay, although these were the Ob River waters of different years, which was disregarded formerly. 相似文献
4.
Isotope parameters (δD, δ<Superscript>18</Superscript>O) and sources of freshwater input to Kara Sea
The isotope characteristics (δD, δ18О) of Kara Sea water were studied for quantitative estimation of freshwater runoff at stations located along transect from Yamal Peninsula to Blagopoluchiya Bay (Novaya Zemlya). Freshwater samples were studied for glaciers (Rose, Serp i Molot) and for Yenisei and Ob estuaries. As a whole, δD and δ18O are higher in glaciers than in river waters. isotope composition of estuarial water from Ob River is δD =–131.4 and δ18O =–17.6‰. Estuarial waters of Yenisei River are characterized by compositions close to those of Ob River (–134.4 and–17.7‰), as well as by isotopically “heavier” compositions (–120.7 and–15.8‰). Waters from studied section of Kara Sea can be product of mixing of freshwater (δD =–119.4, δ18O =–15.5) and seawater (S = 34.9, δD = +1.56, δ18O = +0.25) with a composition close to that of Barents Sea water. isotope parameters of water vary significantly with salinity in surface layer, and Kara Sea waters are desalinated along entire studied transect due to river runoff. concentration of freshwater is 5–10% in main part of water column, and <5% at a depth of >100 m. maximum contribution of freshwater (>65%) was recorded in surface layer of central part of sea. 相似文献
5.
I. I. Pipko I. P. Semiletov P. Ya. Tishchenko S. P. Pugach N. I. Savel’eva 《Oceanology》2008,48(1):54-67
The publication presents the results of the studies on the carbonate system of the waters of the East Siberian Sea performed aboard R/V Ivan Kireev in September 2003–2004. It is shown that the aquatic area considered may be subdivided into two biohydrochemical provinces. The western part of the sea is a CO2 supplier to the atmosphere, while its eastern part is a sink for CO2. This is caused by the fact that the western part of the East Siberian Sea was affected by the waters of the southeastern part of the Laptev Sea, which were desalinated by riverine runoff, turbid, and enriched in the bioactive organic matter supplied into the water due to the coastal (and bottom) erosion. In the eastern part, cold waters of Pacific origin prevailed (saline, transparent, and productive), which caused a pronounced decrease in the partial pressure of CO2(pCO2) in the surface layer. In the frontal zone delimiting the desalinated shelf waters and those of the Pacific origin, the direction of the CO2 flux between the atmosphere and the sea changed (from evasion to invasion). The interannual variability of the carbonate system parameters in the coastal-shelf zone of the East Siberian Sea was determined by the intensity of the propagation of the waters of different origins over the sea aquatic area caused by the atmospheric circulation, as well as by the riverine runoff intensity and the dynamics of erosion processes. 相似文献
6.
This paper considers different types of the continental runoff distribution over the Kara Sea depending on hydrological and meteorological processes based on 1993–2014 expedition data of the Shirshov Institute of Oceanology. The results of calculating the relative contribution of fresh water from several sources (the Ob and Yenisei rivers and melted ice) using hydrochemical parameters are also given. 相似文献
7.
Oceanology - It is believed that the waters of rivers flowing into the Kara Sea (predominantly discharge of the Yenisei and Ob rivers) can propagate to the east, penetrating the Laptev Sea with the... 相似文献
8.
By using the Arctic runoff data from R-ArcticNET V4.0 and ArcticRIMS, trends of four major rivers flowing into the Arctic Ocean, whose climate factor plays an important role in determining the variability of the Arctic runoff, are investigated. The results show that for the past 30 years, the trend of the Arctic runoff is seasonally dependent. There is a significant trend in spring and winter and a significant decreasing trend in summer, leading to the reduced seasonal cycle. In spring, surface air temperature is the dominant factor influencing the four rivers. In summer, precipitation is the most important factor for Lena and Mackenzie, while snow cover is the most important factor for Yenisei and Ob. For Mackenzie, atmospheric circulation does play an important role for all the seasons, which is not the case for the Eurasian rivers. The authors further discuss the relationships between the Arctic runoff and sea ice. Significant negative correlation is found at the mouth of the rivers into the Arctic Ocean in spring, while significant positive correlation is observed just at the north of the mouths of the rivers into the Arctic in summer. In addition, each river has different relationship with sea ice in the eastern Greenland Sea. 相似文献
9.
V. I. Kuzin G. A. Platov E. N. Golubeva 《Izvestiya Atmospheric and Oceanic Physics》2010,46(6):770-783
A numerical simulation with a coupled sea-ice model of the Arctic and North Atlantic oceans is used to study the influence
that the interannual variations in the Siberian river discharge have on the distribution and propagation of freshwater in
this region. In numerical experiments we compared simulations with the use of observational data on the discharge of the most
significant Siberian rivers (Ob, Yenisei, and Lena) against the results of climatic seasonally average variations of their
discharges. This comparison showed that the interannual variations may have significant consequences despite their smallness
when compared with oceanic-scale water transport. These consequences include (1) the intensification of either cyclonic or
anticyclonic components of motion of the subsurface Arctic Ocean waters and, as a result, the redistribution of freshwater
fluxes from Arctic regions between the Fram Strait and the straits of the Canadian Archipelago. A change in the store of fresh
Arctic Ocean waters due to interannual variations in the Ob, Yenisei, and Lena discharges is approximately ±400 km3, whereas the volume of water redirected in this regard, which forms a link between some straits, reaches 15 thousand km3. On the other hand, (2) insignificant changes in the propagation direction of freshwaters are multiply enhanced in the process
of their motion in the North Atlantic as part of the subpolar gyre because of their smaller or larger involvement in the processes
of vertical mixing. As a result of this, anomalies of freshwater develop considerably far from the river mouths, like in the
region of the Azores islands, and are 5–6 times larger than the maximum values of the accumulated variability volumes of the
river discharge. 相似文献
10.
The optical properties and distribution of dissolved organic matter in the surface waters of the Kara Sea and bays of Novaya Zemlya archipelago were studied during the 63th cruise of the R/V Akademik Mstislav Keldysh. The fluorescence of dissolved organic matter has been studied over wide excitation (230–550 nm) and emission (240–650 nm) wavelength ranges. Based on the results of fluorescence measurements, we propose a simple technique for estimating the relative content of humic compounds entering the Kara Sea shelf region with Ob and Yenisei river runoff. We have found that the blue shift parameters of the DOM fluorescence are Δ270–310 = 28 ± 2 nm and Δ355–310 = 29 ± 2 nm. The highest contents of humic compounds in surface waters were measured on the transect across the desalinated layer of the Kara Sea, near the continental slope on the transect along the St. Anna Trough, and in the area of Sedova, Oga and Tsivol’ki bays. Traces of labile terrigenous organic matter were found in the region of the Voronin Trough, in the bays of the Severny Island of Novaya Zemlya, as well as in some freshwater reservoirs and ice samples of the archipelago. We established a conservative distribution of dissolved organic matter, whose content in water varied from 1.25 to 8.55 mg/L. 相似文献
11.
V. Yu. Rusakov T. G. Kuzhmina M. A. Levitan E. S. Toropchenova A. V. Zhylkina 《Oceanology》2017,57(1):192-203
The Kara Sea is part of the Western Arctic shelf of Eurasia. The deposition of sediments in this shallow sea is largely determined by solid runoff from two great Siberian rivers (the Yenisei and Ob) and the glacial periods when the sea area repeatedly (during the Quaternary) dried up and was covered by continental glaciers. The rise of the World Ocean due to Holocene warming resulted in a significant expansion of the sea area to the south and complete degradation of the ice sheet. In this article, new data on the geochemical composition of the surface (0- to 2-cm) layer of sea-bottom sediments are considered, which reflects the spatial distribution of marine sediments during the maximum sea level. Cluster analysis of the variance for 24 chemical elements reveals sediment chemotypes, and critical analysis of their relationship with lithotypes is performed. The presented data have been collected on cruises of the R/V Akademik Boris Petrov in 2000, 2001, and 2003 and the R/V Akademik Mstislav Keldysh in 2015. 相似文献
12.
I. A. Nemirovskaya 《Oceanology》2010,50(5):716-728
Data are presented on the content of aliphatic and polycyclic aromatic hydrocarbons (AHC and PAH, respectively) in the interstitial
waters and bottom sediments of the Kara Sea compared to the distribution of the particulate matter and organic carbon. It
was found that the AHC concentrations within the water mass (16 μg/l on average) are mainly formed by natural processes. The
AHC distribution represents the variability of the hydrological and sedimentation processes in different regions of the sea.
The widest ranges of the concentrations were registered in the Ob Bay-Kara Sea section: in the water (10–310 μg/l for the
AHC and 0.4–7.2 ng/l for the PAH) and in the surface layer of the bottom sediments (8–42 μg/l for the AHC and 9–94 ng/g for
the PAH). The differentiation of the hydrocarbons (HC) in the different media follows the marginal filter’s regularities;
therefore, no oil and pyrogenic compounds are supplied to the open parts of the sea. In the sediment mass, the HC content
is determined by the variations in the oxidative conditions in the sediment and its material’s composition. 相似文献
13.
This study presents a review of extensive literature and reports new findings extracted from previously collected cores. Globally lowered sea level during the last glacial maximum (LGM) reduced the cross-sectional area in the Korea Strait, minimizing volume transport of the paleo-Tsushima Current and increasing freshwater input to the East Sea. The higher supply of freshwater played an important role in compositional changes of surface water in the sea, indicated by low sea surface salinity (down to about 20‰) and light d 18O of planktonic Foraminifera (lighter than 1‰) recorded in core sediments. The Korean fluvial systems (Nakdong and Seomjin rivers) emptying into the southeastern sea of Korea may have contributed substantially to freshwater supply to the surface layer of the LGM East Sea, although Chinese paleo-river (Huanghe and Yangtze rivers) waters, together with the paleo-Tsushima Current, also seem to have supplied some freshwater to the sea. The higher supply of river waters to the East Sea is strongly evidenced by the high amount of terrigenous material (quartz, feldspar and rock fragments) in core sediments. In addition, high magnetic susceptibility, high grain density, and high C/N ratios were documented in cores MB98PC-11 and 95PC-1. In contrast with earlier studies, we propose that Korean rivers played a more substantial role in supplying freshwater to the East Sea during the LGM than previously thought. 相似文献
14.
Suspended matter (SM) and surface sediments were analysed for polycyclic aromatic hydrocarbons (PAH) throughout the Ob and Yenisei River estuaries and in the Kara Sea in order to evaluate the contamination of Arctic shelves by these two major Siberian rivers. PAH concentrations were extremely low, among the lowest measured up to now in the Arctic region. Particle-associated PAH were in many cases non-detectable. A total PAH maximum value of 3·2ngl − 1was found in surface waters. In surficial sediments, they spanned a range from 24 to 115ngg − 2in the Ob River, from 40 to 131ngg − 2in the Yenisei and from 16 to 94ngg − 2in the Kara Sea. Compositional features revealed a contribution of detrital material eroded from soils of the drainage basins and inputs from airborne pyrolytic PAH emitted at lower latitudes and from industrial complexes in Siberia. Particulate and sedimentary PAH distributions were highly variable both in type and concentration. The Ob and Yenisei estuaries are geographically large features where hydro-dynamical and sedimentary processes are complex. As a consequence, inhomogeneities—in the form of patch-structures—develop and make it difficult to resolve the fate of riverborne constituents based on ship measurements only. Remote sensing in conjunction with oceanographic observations may provide further guidance to study large river systems. 相似文献
15.
The phytoplankton of a surface strongly desalinated water lens was investigated on the basis of materials collected during the 57th cruise of the R/V Akademik Mstislav Keldish in September of 2007. The lens with a salinity of <18 psu had area of approximately 19 thousand square kilometers and was located in the northwestern part of the Kara Sea near the eastern coast of Novaya Zemlya. It was a specific biotope that had been isolated from the surrounding waters for more than three months. In the investigated area, 66 algae species were identified. The maximal species diversity was found in the upper layers of the desalinated lens, where the species number was 1.5 to 3 times higher than in other parts of the water column. The phytoplankton numbers in the upper layers of the lens were 1.5 to 4.5 times higher than in its lower part and generally higher than below the picnocline. Diatoms were the most abundant group in the upper layers of the lens, while flagellates dominated in numbers in the subpicnocline part of the water column. The maximal values of the phytoplankton biomass were observed everywhere in the upper layers of the lens, where they were 1.2 to 3.7 times higher than in the lower part of the lens and 1.3 to 7.2 times higher than in the layer below the picnocline. Dinoflagellates generally gave the most contribution to the total phytoplankton biomass. The phytoplankton of the desalinated surface lens in the northwestern part of the Kara Sea by its composition and quantitative parameters had the nearest resemblance to a phytocenosis that we observed two weeks later at a shallow desalinated shelf closely adjacent to the Ob estuary. 相似文献
16.
S. V. Galkin N. V. Kucheruk K. V. Minin A. K. Rayskiy E. I. Goroslavskaya 《Oceanology》2010,50(5):793-797
The composition and distribution of the macrobenthic communities in the Ob estuary and the adjacent Kara Sea shelf were studied
during the 54th cruise of the R/V Akademik Mstislav Keldysh. With the transition from the Ob River’s mouth to the open parts of the sea, the gradual changes of the bottom biocenoses
included changes in the leading taxa. Along with the increase in the salinity, the freshwater and brackish water taxa are
replaced by related forms adapted to dwelling in seawater. The comparison of the original data with the results of the previous
investigations revealed considerable spatial and temporal variations of the bottom communities in the studied area. The main
environmental factors determining the fauna distribution in the estuarine zone are discussed. The extensive biocenosis dominated
by Portlandia aestuariorum in the Ob estuary was found for the first time. 相似文献
17.
The thermohaline and hydrochemical characteristics of the Lena River’s estuarine zone were investigated in the Buor-Khaya
Bay and the southeastern Laptev Sea in September of 2005. A tongue of river water with high nutrient content and increased
turbidity was identified in the bay. It is shown that the two-layer structure in the bay is disturbed by warm freshwater lenses.
The strong vertical stratification in the shelf zone results in sharply contrasting characteristics of the surface and bottom
waters. It is established that the concentrations of biogenic elements regularly change depending on the thermohaline characteristics
of the waters and their stratification degree. Stagnant bottom waters with low dissolved oxygen contents and high concentrations
of phosphates, nitrates, and ammonium are recorded in the eastern part of the bay. The bottom waters have different hydrochemical
characteristics due to their different origin. 相似文献
18.
Spatiotemporal variability of the organic matter and the rates of its transformation in the Ob Inlet
The data on the qualitative and quantitative variability of the organic matter (OM) and its transformation rates in the waters of the Ob Inlet during different seasons are considered. The OM distribution was quite nonuniform over the entire Ob Inlet aquatic area: the concentrations of Corg varied from 2.8 to 14.1 mg/L and from 0.32 to 4.59 mg/L for the dissolved and particulate forms, respectively. The maximum concentrations of dissolved OM were registered in the main flow of the Ob River water supplied to the bay, whereas the minimum concentrations were characteristic for the near-bottom layers formed by the Kara Sea waters of high salinity in the northern part of the bay. Both in the summer and in the autumn, the fraction of particulate matter within the total OM reached its maximum values in the mixing zone of the Taz and Ob riverine waters, as well as in the mixing zone of the Ob River and Kara Sea waters. These boundary zones were characterized by the widest variability of the elemental (C: N: P) and biochemical (proteins and carbohydrates) composition of the OM, as well as of its transformation rates measured by the activities of the enzymes (alkaline phosphatase and the electron transport system). 相似文献
19.
Results of optical studies of the Kara Sea waters are considered. The data of ship borne measurements are compared with satellite
observations. The maximum values of the beam attenuation coefficient, the chlorophyll, and the yellow substance fluorescence
were observed in the Ob gulf and in the coastal waters west of the Yamal Peninsula. The minimum values were observed in the
central and western parts of the Kara Sea. Frontal zones with sharp changes of the parameters involved were observed. The
distribution of the seawater’s optical characteristics was closely related to the hydrological structure of the Kara Sea’s
waters. The data of the shipborne measurements were consistent with the satellite observations. 相似文献
20.
Oceanology - This paper reports the results of investigations on the radioecological state of bottom sediments of the Ob–Yenisei shoal area and Ob and Yenisei estuaries. Materials were... 相似文献