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1.
In 1993 and 2007 when the expeditions of the Shirshov Institute of Oceanology were performed in the Kara Sea, a significant
part of its aquatic area was occupied by lenses of desalinated water. The fresh-water is supplied by the runoff of the Ob
and Yenisei rivers, as well as by meltwaters. The report considers the features of the freshwater chemical transformation
in the sea. It is shown that the contribution of meltwaters is small in the highly desalinated lenses (with salinity below
15‰) and the freshwater is supplied by the riverine runoff. It is also shown that, under definite conditions, it is possible
to determine the relative shares of the Ob and Yenisei waters using the chemical parameters (the silicon and alkalinity).
The data of 1993 when two lenses as such were found in the sea were confirmed; at that, the waters of the Yenisei and Ob rivers
were prevailing in the western and northeastern lenses, respectively. In 2007, one lens was found in the treated area of the
sea. It is shown that the chemical characteristics of the freshwater in the lens appeared to be sufficiently different from
those of the Ob river but similar to the Yenisei river’s characteristics according to the data of 1993. A map of the Ob’s
and the Yenisei’s water spreading over the sea’s aquatic area is presented. 相似文献
2.
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
3.
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
4.
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
5.
The distribution of the suspended particulate matter concentration in the Kara Sea is analyzed based on ship and satellite
data. The statistical relationships between the suspended matter concentration and the optical characteristics were revealed.
Charts of the distribution of the suspended matter concentration in the Kara Sea were plotted, which confirmed that the application
of optical methods for analyzing the spatial distribution of the suspended matter is effective. The most turbid waters were
observed in the Ob Gulf, Yenisei Bay, the Baidaratskaya Gulf, and the adjacent regions. The smallest concentrations of suspended
matter were observed in the central and western parts of the Kara Sea. 相似文献
6.
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
7.
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
8.
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
9.
The paper summarizes results on the content and composition of aliphatic hydrocarbons (HCs) in suspended particulate matter (SPM) and bottom sediments in the Kara, Laptev, and East Siberian seas obtained in 2015–2018. It was established that the “losses” in HC concentrations in surface waters in the river (Ob, Yenisei, Lena, Khatanga, Indigirka, Kolyma) and seawater mixing zone in some cases exceeded their river removal by 90%. The composition of HCs in surface waters depends on the characteristics of the river catchment area, sampling season. and time of day (high/low tide) and basically coincides with the SPM distribution. In the pelagic zone of the seas, the HC content is close to the background (2–7 μg/L). The influence of anthropogenic input was established only in the Gulf of Ob, where the composition of alkanes is close to oil with a HC content of 86 μg/mg SPM. In bottom sediments, the particle size distribution determines the HCs, and terrigenous n-alkanes play the dominant role in the molecular composition.
相似文献10.
K. G. Rubinshtein S. S. Gromov R. Yu. Ignatov 《Izvestiya Atmospheric and Oceanic Physics》2007,43(3):294-307
A short review of snow cover parametrizations used in different atmospheric general circulation models is given. The results of comparison of 20-year mean integral characteristics of snow cover for North America and Eurasia obtained in three Russian models in the AMIP-2 experiments with observations and reanalysis data are analyzed. Results of the models of the Hydrometeorological Centre of Russia, the Institute of Numerical Mathematics of the Russian Academy of Sciences, and the Voeikov Main Geophysical Observatory are used. It is shown that all models better reproduce snow cover characteristics of Eurasia than those of North America, and snow area is reproduced with smaller errors than snow mass. It is also shown that the fall and winter snow cover formation is simulated more closely to the reference data than the spring snowmelt. It is also shown that 20-year mean snow cover changes in watersheds of the Siberian Ob, Yenisei, and Lena rivers are well reproduced in all models. In the fall and winter period of snow cover formation, the model results are close to one another. During a spring rapid snowmelt, the model of the Hydrometeorological Centre is closer to the reference data. 相似文献
11.
The distribution of V, Co, Ni, Sr, Nb and rare earth elements (REE) in ice-rafted sediments (IRS) collected in the Yermak Plateau area (the Arctic Ocean) during cruise ARK-XX/3 of the R/V Polarstern in September 2004 has been analyzed. It was determined that the Nb/V ratio in these IRS has an intermediate value between the average ratio values in suspended particulate matter of the Yenisei and Khatanga rivers and Mesozoic–Cenozoic basalts, on the one hand, and suspended matter of the Ob and Lena rivers and post-Archean Australian Shale (PAAS), on the other hand. The REE distribution demonstrates the same pattern. The IRS data points in Nb-Sr, Ni-Co, and Co-Sr and some other diagrams are close mainly to the average chemical composition of suspended particulate matter of the Ob and Lena rivers, i.e., waterways draining watersheds composed predominantly of sedimentary rocks. The Nb, Sr, Ni, and Co contents in the studied IRS samples are close to those in the PAAS. In accordance with this, we were able to conclude that the main provenance areas of the studied IRS samples are situated in the eastern part of the Laptev Sea and the East Siberian Sea, on shelf of which the erosion products of sedimentary and metamorphic rocks of the Verkhoyansk Fold Belt dominate. 相似文献
12.
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
13.
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
14.
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
15.
巴伦支海-喀拉海是北冰洋最大的边缘海,能够对环境变化做出快速的响应和反馈,是全球气候变化最为敏感的区域之一,其古海洋环境演变及海冰变化研究是全球气候变化研究的重要组成部分。末次盛冰期以来,该区域的古海洋环境受到太阳辐射、海流强度、海平面变化、温盐环流和河流输入等因素影响发生了一系列不同尺度的波动。巴伦支海受到北大西洋暖水和极地冷水两大水团相互作用的影响,在水团交界处 （极锋) 由于不同水团性质的差异,导致其海水温度、盐度及海冰发生剧烈变化。而喀拉海则受到叶尼塞河和鄂毕河大量淡水输入影响,海流系统较巴伦支海相对复杂,沉积物主要来源于河流输入的陆源物质,并可以通过磁化率的分析明确区分两条河流的陆源物质。由于受到冷水和暖水的相互作用,巴伦支海-喀拉海海冰变化迅速,并且在全新世中晚期存在 0.4 ka 和 0.95 ka 的变化周期,但海冰变化的影响因素并不是单一的,而是气候系统内部各因子相互作用的结果。目前古海冰重建研究工作主要为定性研究,定量研究相对较少,所选用的重建指标也相对单一,另外存在年代框架差、分辨率低等不足。本文以巴伦支海和喀拉海为中心,总结了其快速气候突变事件、古温度盐度、海平面及海冰的变化,对影响因素进行了探讨,并通过分析末次盛冰期以来古海洋环境研究的不足,提出了相应的展望。 相似文献
16.
Material is collected on a meridional profile from Yenisei Bay to adjacent parts of the Kara Sea shelf. The length of the profile is 550 km; 13 to 62 m depths. A multiple corer and Niemistö corer are used as sampling tools. The meiobenthos is represented by 13 taxa. Nematodes are the most abundant taxon, and harpacticoid copepods (Harpacticoida) are subdominant. The abundance and taxonomic diversity of meiobenthos and nematodes increases from the freshwater part of Yenisei Bay towards the Kara Sea shelf. Three types of taxocene are distinguished: freshwater, brackish-water, and marine. The taxocene of the estuary is not distinguished by any specific set of species and consists of species characteristic of the nematode community both in the freshwater and marine zones. The trophic structure of the taxocene of nematodes in Yenisei Bay is dominated by nematodes with well-defined stoma and are differently armed. The estuary and shelf are dominated by selective and nonselective deposit feeders. 相似文献
17.
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
18.
In three sections in the Kara Sea, the contents of the dissolved and particulate organic carbon (the DOC and POC, respectively),
as well as of the organic carbon of the bottom sediments (Corg) were determined. The contents of varied from 6.3 to 2400 μg/l for the DOC and from 0.84 to 12.2 mg of C/l for the POC. The
average concentrations for all the samples tested amounted to 200 μg/l for the DOC (n = 78, σ = 368) and 2.7 mg/l for the POC (n = 92, σ = 2.7). The concentrations of Corg in the samples of the upper layer of the bottom sediments of the area treated
varied from 0.13 to 2.10% of the dry substance at an average value of 0.9% (n = 21, σ= 0.49%). It is shown that the distribution of the different forms of organic matter (OM) is an indicator of the supply
and spreading of the particulate matter in the Kara Sea and that the DOC and POC of the Kara Sea are formed under the impact
of the runoff of the Ob and Yenisei river waters. It is found that the distribution of the OM of the bottom sediments in the
surveyed area of the Kara Sea is closely related to their grain-size composition and to the structure of the currents in the
area studied. The variations in the Corg content in the bottom sediment cores from the zone of riverine and marine water mixing
represent the variability of the OM burial. 相似文献
19.
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
20.
Lee W. Cooper J. M. Kelley L. A. Bond K. A. Orlandini J. M. Grebmeier 《Marine Chemistry》2000,69(3-4)
We report here thermal ionization mass spectrometry measurements of 239Pu, 240Pu, 241Pu, 242Pu, and 237Np isolated from oceanic, estuarine, and riverine sediments from the Arctic Ocean Basin. 238Pu/239+240Pu activity ratios are also reported for alpha spectrometric analyses undertaken on a subset of these samples. Our results indicate that the Pu in sediments on the Alaskan shelf and slope, as well as that in the deep basins (Amerasian and Eurasian) of the Arctic Ocean, has its origin in stratospheric and tropospheric fallout. Sediments from the Ob and Yenisei Rivers show isotopic Pu signatures that are distinctly different from those of northern-hemisphere stratospheric fallout and indicate the presence of weapons-grade Pu originating from nuclear fuel reprocessing wastes generated at Russian facilities within these river catchments. Consequently, sediments of the Eurasian Arctic Ocean, particularly those in the Barents and Kara Seas, probably contain a mixture of Pu from stratospheric fallout, tropospheric fallout, and fuel-reprocessing wastes of riverine origin. In particular, the 241Pu/239Pu ratios observed in these sediments are inconsistent with significant contributions of Pu to the arctic sediments studied from western European reprocessing facilities, principally Sellafield in the UK. Several other potential sources of Pu to arctic sediments can also be excluded as significant based upon the transuranic isotope ratios presented. 相似文献