scholarly journals The quantitative definition of the Barents Sea Atlantic Water: mapping of the annual climatic cycle and interannual variability

2003 ◽  
Vol 60 (4) ◽  
pp. 836-845 ◽  
Author(s):  
I. Smolyar ◽  
N. Adrov
Keyword(s):  
Decision Rule ◽  
Barents Sea ◽  
Winter Season ◽  
Atlantic Water ◽  
The Barents Sea ◽  
Straight Line ◽  
Monthly Distribution ◽  
Definition Of ◽  
Quantitative Definition ◽  
Mixed Water

Abstract The Barents Sea Atlantic Water (AW) is defined in eight different ways in the literature. These definitions can be consolidated into one statement (decision rule) that allows the separation of the AW of the Barents Sea from the rest of the water masses there. The decision rule defines AW as a straight-line function of temperature and salinity and non-Atlantic Water and Mixed Water by their proximity to AW on a temperature–salinity diagram. This rule is used to map the monthly-mean distribution of AW in the Barents Sea at 0, 30, 50 and 100 m depths. These maps demonstrate two stable seasons (winter and summer) of AW intrusion into the Barents Sea. The average duration of the AW-winter season is five months (January to May), whilst that of the AW-summer season is four months (July to October). During the winter, the area coverage of the AW at the surface equals 23% and varies slightly with depth. During summer, there is zero areal coverage of the AW at the surface, and with depth it varies considerably. The decision rule was used to map the monthly distribution of AW along latitude 74°30′N in the Barents Sea for the period 1975–1989. The maximum inflow of AW into the Barents Sea along 74°30′N occurs during March. The minimum inflow of AW occurs in August. The March/August inflow ratio is 1.55.

scholarly journals Distribution and seasonal dynamics of bacterioplankton along the westernborder of the Barents Sea.

2020 ◽  
Vol 11 (5-2020) ◽  
pp. 37-50
Author(s):  
M.P. Venger ◽  
Keyword(s):  
Barents Sea ◽  
Structural Characteristics ◽  
Single Cells ◽  
Winter Season ◽  
Polar Front ◽  
Summer Season ◽  
Total Biomass ◽  
Summer Period ◽  
The Barents Sea ◽  
Summer Maximum

The structural characteristics of bacterioplankton were studied in the waters of the Cape`s Nordkap (cut I) and Zuydkap (cut II) of Mezhvezhiy island. Its abundance and biomass in the upper part of the photic layer of coastal and Atlantic waters in cut I was comparable and increased from the late spring to the summer season. Moreover, in cuts I and II, the values of summer maximum corresponded to the zone of the Polar Front and adjacent Arctic waters. By the beginning of the winter season, the level of development of communities in waters of different genesis decreased everywhere, but still did not reach the minimum, observed insummer in layers deeper than 200 m. The structure of bacterioplankton was determined by single cells of the smallest size, mainly of a cocci-form. The arrival of rod-shaped bacteria (contribution to the total biomass could reach 50%) was recorded in the summer period.

scholarly journals Transformation of Atlantic Water in the north-eastern Barents Sea in winter

2020 ◽  
Vol 66 (3) ◽  
pp. 246-266
Author(s):  
V. V. Ivanov ◽  
I. E. Frolov ◽  
K. V. Filchuk
Keyword(s):  
Barents Sea ◽  
Cold Season ◽  
Atlantic Water ◽  
High Concentration ◽  
The North ◽  
Driving Mechanisms ◽  
The Barents Sea ◽  
Open Sea ◽  
North Eastern ◽  
Transformation Mechanisms

Hydrographic observations, carried out in March-May, 2019 during “Transarktika-2019” expedition onboard R/V “Akademik Tryoshnikov” allowed studying mechanisms of Atlantic Water (AW) transformation in the Barents Sea. Although this research topic is rather traditional for oceanographic studies, there are still a number of questions, which require clarification. Among these is a deeper understanding of the AW transformation in specific regions in cold season, when the coverage by observations is scarce. In this study we performed temperature and salinity (TS) analysis of conductivity — temperature — depth (CTD) data, collected in the north-eastern “corner” of the Barents Sea — this is the area with difficult access in winter due to high concentration of pack ice. The results allowed identification of areas along the pathways of AW branches, where various types of open sea convection and cascading acted as dominant processes of AW properties change. We distinguish several driving mechanisms controlling modification of the waters of Atlantic origin. An advantage of winter measurements is that the active stage of AW transformation mechanisms is explicitly observed at the consecutive CTD sections.

Palynological evidence of sea-surface conditions in the Barents Sea off northeast Svalbard during the postglacial period

2020 ◽  
pp. 1-15
Author(s):  
Camille Brice ◽  
Anne de Vernal ◽  
Elena Ivanova ◽  
Simon van Bellen ◽  
Nicolas Van Nieuwenhove
Keyword(s):  
Sea Ice ◽  
Surface Waters ◽  
Barents Sea ◽  
Ice Cover ◽  
Atlantic Water ◽  
Transitional Period ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Conditions ◽  
The Barents Sea

Abstract Postglacial changes in sea-surface conditions, including sea-ice cover, summer temperature, salinity, and productivity were reconstructed from the analyses of dinocyst assemblages in core S2528 collected in the northwestern Barents Sea. The results show glaciomarine-type conditions until about 11,300 ± 300 cal yr BP and limited influence of Atlantic water at the surface into the Barents Sea possibly due to the proximity of the Svalbard-Barents Sea ice sheet. This was followed by a transitional period generally characterized by cold conditions with dense sea-ice cover and low-salinity pulses likely related to episodic freshwater or meltwater discharge, which lasted until 8700 ± 700 cal yr BP. The onset of “interglacial” conditions in surface waters was marked by a major change in dinocyst assemblages, from dominant heterotrophic to dominant phototrophic taxa. Until 4100 ± 150 cal yr BP, however, sea-surface conditions remained cold, while sea-surface salinity and sea-ice cover recorded large amplitude variations. By ~4000 cal yr BP optimum sea-surface temperature of up to 4°C in summer and maximum salinity of ~34 psu suggest enhanced influence of Atlantic water, and productivity reached up to 150 gC/m2/yr. After 2200 ± 1300 cal yr BP, a distinct cooling trend accompanied by sea-ice spreading characterized surface waters. Hence, during the Holocene, with exception of an interval spanning about 4000 to 2000 cal yr BP, the northern Barents Sea experienced harsh environments, relatively low productivity, and unstable conditions probably unsuitable for human settlements.

scholarly journals Comparison of the biophysical and trophic characteristics of the Bering and Barents Seas

2005 ◽  
Vol 62 (7) ◽  
pp. 1245-1255 ◽  
Author(s):  
George L. Hunt ◽  
Bernard A. Megrey
Keyword(s):  
Bering Sea ◽  
Barents Sea ◽  
Single Species ◽  
Atlantic Water ◽  
Walleye Pollock ◽  
Fish Stocks ◽  
Eastern Bering Sea ◽  
The Barents Sea ◽  
Shelf Seas ◽  
Bottom Waters

Abstract The eastern Bering Sea and the Barents Sea share a number of common biophysical characteristics. For example, both are seasonally ice-covered, high-latitude, shelf seas, dependent on advection for heat and for replenishment of nutrients on their shelves, and with ecosystems dominated by a single species of gadoid fish. At the same time, they differ in important respects. In the Barents Sea, advection of Atlantic Water is important for zooplankton vital to the Barents Sea productivity. Advection of zooplankton is not as important for the ecosystems of the southeastern Bering Sea, where high levels of diatom production can support production of small, neritic zooplankton. In the Barents Sea, cod are the dominant gadoid, and juvenile and older fish depend on capelin and other forage fish to repackage the energy available in copepods. In contrast, the dominant fish in the eastern Bering Sea is the walleye pollock, juveniles and adults of which consume zooplankton directly. The southeastern Bering Sea supports considerably larger fish stocks than the Barents. In part, this may reflect the greater depth of much of the Barents Sea compared with the shallow shelf of the southeastern Bering. However, walleye pollock is estimated to occupy a trophic level of 3.3 as compared to 4.3 for Barents Sea cod. This difference alone could have a major impact on the abilities of these seas to support a large biomass of gadoids. In both seas, climate-forced variability in advection and sea-ice cover can potentially have major effects on the productivity of these Subarctic seas. In the Bering Sea, the size and location of pools of cold bottom waters on the shelf may influence the likelihood of predation of juvenile pollock.

Definition of Efficiency and Safety Criteria for Icebreaker in Ice Management Operations

2018 ◽  
Author(s):  
Evgeny Karulin ◽  
Marina Karulina ◽  
Mikhail Kazantsev ◽  
Aleksander Proniashkin ◽  
Dmitry Zaikin
Keyword(s):  
Case Studies ◽  
Oil And Gas ◽  
Barents Sea ◽  
Operational Performance ◽  
Marine Structures ◽  
Efficient Operation ◽  
Offshore Production ◽  
The Barents Sea ◽  
Definition Of ◽  
The Right

Ice management (IM) is often required to support offshore production of oil and gas in freezing seas. It helps to mitigate ice impact on marine structures and thus minimize risks of accidents as well as to increase weather windows for marine operations. One of the IM tactics is to use an icebreaker for producing a zone of managed ice for ensuring safe and efficient operation of marine facilities: platforms, offloading terminals, tankers, etc. The choice of the right icebreaker which is best capable to cope with the IM jobs is quite a challenging task. This paper suggests an approach to objectively compare operational efficiency of different icebreakers in performance of some typical IM tasks. This approach made it possible to work out universal criteria for assessing the efficiency of these ships. The criteria of icebreaker efficiency and operational performance have been derived from actual ice breaking and maneuvering data including safety aspects of required icebreaker maneuvers. The paper contains case studies with estimation of the said criteria for a number of IM icebreakers expected to be used for ice management in the south-eastern part of the Barents Sea.

A satellite-based Lagrangian perspective on Atlantic Water fractionation in the Nordic Seas

2020 ◽  
Author(s):  
Léon Chafik ◽  
Sara Broomé
Keyword(s):  
Arctic Ocean ◽  
Barents Sea ◽  
Bottom Topography ◽  
Atlantic Water ◽  
The Arctic ◽  
Fram Strait ◽  
Nordic Seas ◽  
The Barents Sea ◽  
The Arctic Ocean ◽  
Outer Branch

<p>The Arctic Ocean has been receiving more of the warm and saline Atlantic Water in the past decades. This water mass enters the Arctic Ocean via two Arctic gateways: the Barents Sea Opening and the Fram Strait. Here, we focus on the fractionation of Atlantic Water at these two gateways using a Lagrangian approach based on satellite-derived geostrophic velocities. Simulated particles are released at 70N at the inner and outer branch of the North Atlantic current system in the Nordic Seas. The trajectories toward the Fram Strait and Barents Sea Opening are found to be largely steered by the bottom topography and there is an indication of an anti-phase relationship in the number of particles reaching the gateways. There is, however, a significant cross-over of particles from the outer branch to the inner branch and into the Barents Sea, which is found to be related to high eddy kinetic energy between the branches. This cross-over may be important for Arctic climate variability.</p>

Marine Operation Windows Offshore Norway

2016 ◽  
Author(s):  
Bjarte O. Kvamme ◽  
Adekunle P. Orimolade ◽  
Sverre K. Haver ◽  
Ove T. Gudmestad
Keyword(s):  
North Sea ◽  
Barents Sea ◽  
Winter Season ◽  
Polar Lows ◽  
Norwegian Sea ◽  
The North ◽  
The Barents Sea ◽  
The North Sea ◽  
Wave Conditions ◽  
Buoy Measurements

A study of the wave conditions in the North Sea, the Norwegian Sea and the Barents Sea is presented in this paper. For each region, one reference location for which there are buoy measurements is selected. For the selected locations, WAM10 hindcast data are obtained from the Norwegian Meteorological Institute (MET Norway). The hindcast data for each location cover the period from 1957 to 2014. First, the hindcast datasets were validated against available buoy measurements — both for extreme value predictions and for application of hindcast data for planning of marine operations. The validation was carried out considering the winter season and the summer season separately. For each season, the datasets for two consecutive months were used. A comparison of the time-series of the hindcast datasets against the buoy measurements showed that the hindcast datasets compared relatively well with the buoy measurements. However, a comparison of the statistical parameters of the hindcast datasets against the buoy measurements showed that the hindcast datasets are slightly conservative in the estimate of the significant wave height for the Barents Sea and the Norwegian Sea. Overall, the data compared well, and the hindcast datasets are therefore considered in the following analysis. Hindcast data from these 57 years show that the wave conditions in the selected Norwegian Sea location is harsher than the wave conditions in both the North Sea and the Barents Sea locations. This is in agreement with the general expected spatial trend in the wave climate on the Norwegian Continental Shelf (NCS). It was also observed that the wave conditions in the selected Barents Sea location are harsher than the wave conditions in the North Sea. These findings are also reflected in the NORSOK N-003 standard on “Actions and Action effects” (NORSOK, 2015). The weather windows for weather-sensitive marine operations, that is, operations with operational reference period not exceeding 72 hours, were established from the hindcast dataset for each of the locations. It was observed that the Norwegian Sea has shorter weather windows, especially in the winter seasons, compared to both the Barents Sea and the North Sea. It was expected that the operational windows would be shorter in the winter seasons in the Barents Sea, due to the occurrence of polar lows. However, the polar lows are few and cause more concern related to forecasting of the weather conditions to start actual marine operations. Generally, the month with the highest probability of weather windows exceeding 72 hours was found to be July for all three locations.

scholarly journals Atlantic water temperature and climate in the Barents Sea, 2000–2009

2012 ◽  
Vol 69 (5) ◽  
pp. 833-840 ◽  
Author(s):  
Vladimir D. Boitsov ◽  
Alexey L. Karsakov ◽  
Alexander G. Trofimov
Keyword(s):  
Water Temperature ◽  
Barents Sea ◽  
Ice Cover ◽  
Atlantic Water ◽  
Climate Index ◽  
Mean Annual Temperature ◽  
Positive Trend ◽  
Late 20Th Century ◽  
The Barents Sea ◽  
Using Data

Abstract Boitsov, V. D., Karsakov, A. L., and Trofimov, A. G. 2012. Atlantic water temperature and climate in the Barents Sea, 2000–2009. – ICES Journal of Marine Science, 69: 833–840. Year-to-year variability in the temperature of Atlantic water (AW), which has a strong influence on the marine climate and ecosystem of the Barents Sea, was analysed using data from the Kola Section. With a positive trend in mean annual temperature during the late 20th century, only positive anomalies were registered during the past decade. In nine of those years, the temperature was warmer than the 1951–2000 long-term mean by 0.5–1.2°C, and in 2006, the historical maximum for the 110-year period of observations along the section was recorded. High air and water temperature coincided with reduced sea-ice cover, especially between October and April, when there is seasonal enlargement of the ice-covered area. An integral climate index (CI) of the Barents Sea based on the variability in temperature of AW, air temperature, and ice cover is presented. A prediction of future Barents Sea climate to 2020 is given by extrapolating the sixth degree polynomial approximating the CI.

scholarly journals On available energy in the ocean and its application to the Barents Sea

2007 ◽  
Vol 4 (6) ◽  
pp. 897-931
Author(s):  
R. C. Levine ◽  
D. J. Webb
Keyword(s):  
Arctic Ocean ◽  
Barents Sea ◽  
Exact Expression ◽  
The Arctic ◽  
Global Ocean ◽  
Boundary Current ◽  
Available Energy ◽  
The Barents Sea ◽  
The Arctic Ocean ◽  
Definition Of

Abstract. Following meteorological practice the definition of available potential energy in the ocean is conventionally defined in terms of the properties of the global ocean. However there is also a requirement for a localised definition, for example the energy released when shelf water cascades down a continental shelf in the Arctic and enters a boundary current. In this note we start from first principals to obtain an exact expression for the available energy (AE) in such a situation. We show that the available energy depends on enstrophy and gravity. We also show that it is exactly equal to the work done by the pressure gradient and by buoyancy. The results are used to investigate the distribution of AE in the Barents Sea and surrounding regions relative to the interior of the Arctic Ocean. We find that water entering the Barents Sea from the Atlantic already has a high AE, that it is increased by cooling but that much of the increase is lost overcoming turbulence during the passage through the region to the Arctic Ocean. However on entering the Arctic enough available energy remains to drive a significant current around the margin of the ocean. The core of raised available energy also acts as a tracer which can be followed along the continental slope beyond the dateline.

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