scholarly journals Short Commentary on Marine Productivity at Arctic Shelf Breaks: Upwelling, Advection and Vertical Mixing

2017 ◽  
Author(s):  
Achim Randelhoff ◽  
Arild Sundfjord
Keyword(s):  
Barents Sea ◽  
Dominant Role ◽  
Vertical Mixing ◽  
Ice Cover ◽  
Shelf Break ◽  
The Arctic ◽  
Ample Evidence ◽  
Atlantic Sector ◽  
Spatially Resolved ◽  
Short Commentary

Abstract. The future of Arctic marine ecosystems has received increasing attention in recent years as the extent of the sea ice cover is dwindling. Although the Pacific and Atlantic inflows both import huge quantities of nutrients and plankton, they feed into the Arctic Ocean in quite diverse regions. The strongly stratified Pacific sector has a historically heavy ice cover, a shallow shelf and dominant upwelling-favourable winds, while the Atlantic sector is weakly stratified, with a dynamic ice edge and a complex bathymetry. We argue that shelf break upwelling is likely not a universal but rather a regional, albeit recurring feature of the new Arctic. Instead, it is the regional oceanography that decides its importance through a range of diverse factors such as stratification, bathymetry and wind forcing. Teasing apart their individual contributions in different regions can only be achieved by spatially resolved timeseries and dedicated modelling efforts. The Northern Barents Sea shelf is an example of a region where shelf break upwelling likely does not play a dominant role, in contrast to the shallower shelves north of Alaska, where ample evidence for its importance has already accumulated.

scholarly journals Short commentary on marine productivity at Arctic shelf breaks: upwelling, advection and vertical mixing

Ocean Science ◽  
2018 ◽  
Vol 14 (2) ◽  
pp. 293-300 ◽  
Author(s):  
Achim Randelhoff ◽  
Arild Sundfjord
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Dominant Role ◽  
Ice Cover ◽  
Atlantic Water ◽  
Shelf Break ◽  
Arctic Shelf ◽  
The Arctic ◽  
Ample Evidence ◽  
Atlantic Sector

Abstract. The future of Arctic marine ecosystems has received increasing attention in recent years as the extent of the sea ice cover is dwindling. Although the Pacific and Atlantic inflows both import huge quantities of nutrients and plankton, they feed into the Arctic Ocean in quite diverse regions. The strongly stratified Pacific sector has a historically heavy ice cover, a shallow shelf and dominant upwelling-favourable winds, while the Atlantic sector is weakly stratified, with a dynamic ice edge and a complex bathymetry. We argue that shelf break upwelling is likely not a universal but rather a regional, albeit recurring, feature of “the new Arctic”. It is the regional oceanography that decides its importance through a range of diverse factors such as stratification, bathymetry and wind forcing. Teasing apart their individual contributions in different regions can only be achieved by spatially resolved time series and dedicated modelling efforts. The Northern Barents Sea shelf is an example of a region where shelf break upwelling likely does not play a dominant role, in contrast to the shallower shelves north of Alaska where ample evidence for its importance has already accumulated. Still, other factors can contribute to marked future increases in biological productivity along the Arctic shelf break. A warming inflow of nutrient-rich Atlantic Water feeds plankton at the same time as it melts the sea ice, permitting increased photosynthesis. Concurrent changes in sea ice cover and zooplankton communities advected with the boundary currents make for a complex mosaic of regulating factors that do not allow for Arctic-wide generalizations.

scholarly journals Polar cod in jeopardy under the retreating Arctic sea ice

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Mats Brockstedt Olsen Huserbråten ◽  
Elena Eriksen ◽  
Harald Gjøsæter ◽  
Frode Vikebø
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Keystone Species ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Biophysical Model ◽  
The Arctic ◽  
Polar Cod ◽  
Arctic Sea ◽  
Shelf Sea

Abstract The Arctic amplification of global warming is causing the Arctic-Atlantic ice edge to retreat at unprecedented rates. Here we show how variability and change in sea ice cover in the Barents Sea, the largest shelf sea of the Arctic, affect the population dynamics of a keystone species of the ice-associated food web, the polar cod (Boreogadus saida). The data-driven biophysical model of polar cod early life stages assembled here predicts a strong mechanistic link between survival and variation in ice cover and temperature, suggesting imminent recruitment collapse should the observed ice-reduction and heating continue. Backtracking of drifting eggs and larvae from observations also demonstrates a northward retreat of one of two clearly defined spawning assemblages, possibly in response to warming. With annual to decadal ice-predictions under development the mechanistic physical-biological links presented here represent a powerful tool for making long-term predictions for the propagation of polar cod stocks.

scholarly journals Recent advances in understanding the Arctic climate system state and change from a sea ice perspective: a review

2014 ◽  
Vol 14 (7) ◽  
pp. 10929-10999 ◽  
Author(s):  
R. Döscher ◽  
T. Vihma ◽  
E. Maksimovich
Keyword(s):  
Global Warming ◽  
Sea Ice ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Climate System ◽  
Arctic Climate ◽  
The Arctic ◽  
Atlantic Sector ◽  
Sea Ice Decline ◽  
Arctic Sea

Abstract. The Arctic sea ice is the central and essential component of the Arctic climate system. The depletion and areal decline of the Arctic sea ice cover, observed since the 1970's, have accelerated after the millennium shift. While a relationship to global warming is evident and is underpinned statistically, the mechanisms connected to the sea ice reduction are to be explored in detail. Sea ice erodes both from the top and from the bottom. Atmosphere, sea ice and ocean processes interact in non-linear ways on various scales. Feedback mechanisms lead to an Arctic amplification of the global warming system. The amplification is both supported by the ice depletion and is at the same time accelerating the ice reduction. Knowledge of the mechanisms connected to the sea ice decline has grown during the 1990's and has deepened when the acceleration became clear in the early 2000's. Record summer sea ice extents in 2002, 2005, 2007 and 2012 provided additional information on the mechanisms. This article reviews recent progress in understanding of the sea ice decline. Processes are revisited from an atmospheric, ocean and sea ice perspective. There is strong evidence for decisive atmospheric changes being the major driver of sea ice change. Feedbacks due to reduced ice concentration, surface albedo and thickness allow for additional local atmosphere and ocean influences and self-supporting feedbacks. Large scale ocean influences on the Arctic Ocean hydrology and circulation are highly evident. Northward heat fluxes in the ocean are clearly impacting the ice margins, especially in the Atlantic sector of the Arctic. Only little indication exists for a direct decisive influence of the warming ocean on the overall sea ice cover, due to an isolating layer of cold and fresh water underneath the sea ice.

scholarly journals New species of Scolelepis (Polychaeta, Spionidae) from the Norwegian coast and Barents Sea with a brief review of the genus

2015 ◽  
Vol 35 ◽  
pp. 9 ◽  
Author(s):  
Andrey Sikorski ◽  
Lyudmila Pavlova
Keyword(s):  
New Species ◽  
Kola Peninsula ◽  
Climate Warming ◽  
Barents Sea ◽  
Identification Key ◽  
The Arctic ◽  
Atlantic Sector ◽  
Norwegian Coast ◽  
The Barents Sea

<p>The species <em>Scolelepis finmarchicus</em> sp. nov. is described from the Norwegian and Barents Seas along the northern Norwegian coast and Kola peninsula. The occurrence of this species in the Kola Bay could be seen as a sign of climate warming in the area. Taxonomic issues existing in the genus <em>Scolelepis</em> within the area along the Norwegian coast and in the Barents Sea are briefly touched upon. Seven species belonging to <em>Scolelepis</em> have recently been recorded from the Atlantic sector of the Arctic. <em>Scolelepis</em> (<em>S</em>.) <em>matsugae</em> Sikorski, 1994 is newly synonymized with <em>S</em>. (<em>S</em>.) <em>laonicola</em> (Tzetlin, 1985). This article provides a brief review of <em>Scolelepis</em> together with an identification key for the genus from the Atlantic sector of the Arctic</p>

Regularities and features of ice conditions of the Barents Sea in the second half of XX – early XXI century

2021 ◽  
pp. 179-194
Author(s):  
I.O. Dumanskaya ◽  
Keyword(s):  
Barents Sea ◽  
Ice Cover ◽  
Heat Fluxes ◽  
The Arctic ◽  
Cycle Period ◽  
Arctic Seas ◽  
Sea Ice Extent ◽  
The Barents Sea ◽  
Western Border ◽  
Quantitative Changes

The warming of the Arctic, especially intensified at the beginning of the XXI century, is accompanied by a significant decrease in the area of ice cover in the Arctic seas. The article shows the quantitative changes in the ice parameters of the Barents Sea, as well as factors affecting the formation of ice cover in recent years. In the twenty-first century the frequency of occurrence of mild winters has increased by 17%, the frequency of severe winters has decreased by 19%. Significantly increased the temperature at the meteorological station Malye Karmakuly, water temperature at transect "Kola Meridian", atmospheric and oceanic heat fluxes, and speed of sea currents on the Western border of the Barents sea. The duration of the ice period decreased by an average of 2–3 weeks, and the rate of reduction of ice cover was 7.2% for 10 years. This is the highest speed compared to other Arctic seas. The article shows that the variability of the ice cover of the Barents Sea and other parameters of the natural environment in the region has the cyclic character. Presumably, the cycle period is close to 84 years, which corresponds to the orbital period of Uranium. The minimum sea ice extent after 1935–1945 is expected in the period 2019–2029.

scholarly journals The evolution of light and vertical mixing across a phytoplankton ice-edge bloom

Elem Sci Anth ◽  
2019 ◽  
Vol 7 ◽  
Author(s):  
Achim Randelhoff ◽  
Laurent Oziel ◽  
Philippe Massicotte ◽  
Guislain Bécu ◽  
Martí Galí ◽  
...  
Keyword(s):  
Chlorophyll A ◽  
Vertical Mixing ◽  
World Ocean ◽  
Ocean Dynamics ◽  
The Arctic ◽  
Upper Ocean ◽  
Melt Mixing ◽  
Atlantic Sector ◽  
West Greenland ◽  
Ice Edge

During summer, phytoplankton can bloom in the Arctic Ocean, both in open water and under ice, often strongly linked to the retreating ice edge. There, the surface ocean responds to steep lateral gradients in ice melt, mixing, and light input, shaping the Arctic ecosystem in unique ways not found in other regions of the world ocean. In 2016, we sampled a high-resolution grid of 135 hydrographic stations in Baffin Bay as part of the Green Edge project to study the ice-edge bloom, including turbulent vertical mixing, the under-ice light field, concentrations of inorganic nutrients, and phytoplankton biomass. We found pronounced differences between an Atlantic sector dominated by the warm West Greenland Current and an Arctic sector with surface waters originating from the Canadian archipelago. Winter overturning and thus nutrient replenishment was hampered by strong haline stratification in the Arctic domain, whereas close to the West Greenland shelf, weak stratification permitted winter mixing with high-nitrate Atlantic-derived waters. Using a space-for-time approach, we linked upper ocean dynamics to the phytoplankton bloom trailing the retreating ice edge. In a band of 60 km (or 15 days) around the ice edge, the upper ocean was especially affected by a freshened surface layer. Light climate, as evidenced by deep 0.415 mol m–2 d–1 isolumes, and vertical mixing, as quantified by shallow mixing layer depths, should have permitted significant net phytoplankton growth more than 100 km into the pack ice at ice concentrations close to 100%. Yet, under-ice biomass was relatively low at 20 mg chlorophyll-a m–2 and depth-integrated total chlorophyll-a (0–80 m) peaked at an average value of 75 mg chlorophyll-a m–2 only around 10 days after ice retreat. This phenological peak may hence have been the delayed result of much earlier bloom initiation and demonstrates the importance of temporal dynamics for constraints of Arctic marine primary production.

scholarly journals Recent advances in understanding the Arctic climate system state and change from a sea ice perspective: a review

2014 ◽  
Vol 14 (24) ◽  
pp. 13571-13600 ◽  
Author(s):  
R. Döscher ◽  
T. Vihma ◽  
E. Maksimovich
Keyword(s):  
Global Warming ◽  
Sea Ice ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
Climate System ◽  
Arctic Climate ◽  
The Arctic ◽  
Central Component ◽  
Atlantic Sector ◽  
Sea Ice Decline

Abstract. Sea ice is the central component and most sensitive indicator of the Arctic climate system. Both the depletion and areal decline of the Arctic sea ice cover, observed since the 1970s, have accelerated since the millennium. While the relationship of global warming to sea ice reduction is evident and underpinned statistically, it is the connecting mechanisms that are explored in detail in this review. Sea ice erodes both from the top and the bottom. Atmospheric, oceanic and sea ice processes interact in non-linear ways on various scales. Feedback mechanisms lead to an Arctic amplification of the global warming system: the amplification is both supported by the ice depletion and, at the same time, accelerates ice reduction. Knowledge of the mechanisms of sea ice decline grew during the 1990s and deepened when the acceleration became clear in the early 2000s. Record minimum summer sea ice extents in 2002, 2005, 2007 and 2012 provide additional information on the mechanisms. This article reviews recent progress in understanding the sea ice decline. Processes are revisited from atmospheric, oceanic and sea ice perspectives. There is strong evidence that decisive atmospheric changes are the major driver of sea ice change. Feedbacks due to reduced ice concentration, surface albedo, and ice thickness allow for additional local atmospheric and oceanic influences and self-supporting feedbacks. Large-scale ocean influences on Arctic Ocean hydrology and circulation are highly evident. Northward heat fluxes in the ocean are clearly impacting the ice margins, especially in the Atlantic sector of the Arctic. There is little indication of a direct and decisive influence of the warming ocean on the overall sea ice cover, due to an isolating layer of cold and fresh water underneath the sea ice.

Temporary seismic network on drifting ice in the North Barents Sea

2020 ◽  
Author(s):  
Andrey Jakovlev ◽  
Sergey Kovalev ◽  
Egor Shimanchuk ◽  
Evgeniy Shimanchuk ◽  
Aleksey Nubom
Keyword(s):  
New Technologies ◽  
Barents Sea ◽  
Seismic Signal ◽  
Ice Cover ◽  
The Arctic ◽  
Stick Slip ◽  
Seismic Stations ◽  
The North ◽  
Drifting Ice ◽  
Ice Floes

&lt;p&gt;Despite the strong attention to the investigations in the Arctic its advance quite slowly. The harsh climatic conditions and big expenses slow down realization of the fieldwork in high latitudes. Therefore, scientists from over the world looks for new technologies, which could optimize and reduce the costs of the fieldworks that aimed at investigation of the geological structure beneath the Arctic Ocean. From March to May 2019 scientific expedition on the Expedition Vessel &amp;#8220;Akademic Tryoshnikov&amp;#8221; operated by the Arctic and Antarctic Research Institute that belongs to Rosgidromet were conducted in the framework of the program &amp;#8220;TransArctica 2019&amp;#8221; first stage. In the framework of the seismological experiments 6 temporary seismic stations at 4 different locations were installed on a drifted ice floe in the North Barents Sea. The first aim of the experiment was to elaborate technology of installation of the seismic stations on the drifting ice floes. The second aim was to check if obtained seismological records could be used for registration of the local and remote earthquakes, which are meant to investigate the lithosphere structure in the Arctic regions, and for investigation of the processes within the ice floe.&lt;/p&gt;&lt;p&gt;The stations were installed in the April 2019 on the ice floe near the EV &amp;#8220;Akademik Tryoshnikov&amp;#8221; that were &amp;#8220;frizzed&amp;#8221; in the ice floe and drifted together with them. After analysis of the recoded data the following types of the seismic signal generated by processes in the ice were observed:&lt;/p&gt;&lt;ul&gt;&lt;li&gt;- background signal from bending-gravitational waves with periods from 1 to 30 sec. Swell waves with periods from 17 to 30 sec were observed permanently during the whole period of network operation;&lt;/li&gt; &lt;li&gt;- continuous mechanical vibrations (self-oscillations) with a period of up to 2-3 sec;&lt;/li&gt; &lt;li&gt;- stick-slip relaxation self-oscillations with a period from 0.1 s to several minutes;&lt;/li&gt; &lt;li&gt;- mechanical movements of ice due to compression or stretching of ice caused by chaotic different scales fluctuations in the drift velocity of ice floes;&lt;/li&gt; &lt;li&gt;- process of ice fracturing due to compression or stretching of ice.&lt;/li&gt; &lt;/ul&gt;&lt;p&gt;Results of monitoring of the ice cover has shown that in the most cases there are no direct correlations of processes within the ice floes and local hydrometeorological condition. During the process of ice cover fracturing an increased value of the ice horizontal movement were observed. Analysis of the seismic signal from ice events has shown that stick-slip events preceded origin of the ice fractures.&lt;/p&gt;&lt;p&gt;As a result of the initial analysis of the seismograms several signals from remote and regional earthquakes were detected. For example, an earthquake that according to the ISC bulletin occur at 08:18:23UTC on April 11, 2019 near the Japan (40.35&amp;#176;N, 143.35&amp;#176;E, 35 km depth, MS = 6.0) were detected. A local earthquake that occur approximately at 05:58UTC on April 10, 2019 at a distance of ~500 km. Due to close location of stations to each other the localization of the earthquake is impossible.&lt;/p&gt;&lt;p&gt;This work is supported by the RSCF project #18-17-00095.&lt;/p&gt;

scholarly journals Causes and features of long-term variability of the ice extent in the Barents Sea

2019 ◽  
Vol 59 (1) ◽  
pp. 112-122 ◽  
Author(s):  
S. B. Krasheninnikova ◽  
M. A. Krasheninnikova
Keyword(s):  
North Atlantic ◽  
Barents Sea ◽  
Arctic Basin ◽  
Atlantic Multidecadal Oscillation ◽  
Ice Cover ◽  
The Arctic ◽  
Model Calculations ◽  
The North ◽  
The Barents Sea ◽  
Cross Correlation Analysis

Based on the spectral analysis of a number of estimates of the ice extent of the Barents Sea, obtained from instrumental observational data for 1900–2014, and for the selected CMIP5 project models (MPI-ESM-LR, MPI-ESMMR and GFDL-CM3) for 1900–2005, a typical period of ~60‑year inter-annual variability associated with the Atlantic multidecadal oscillation (AMO) in conditions of a general significant decrease in the ice extent of the Barents Sea, which, according to observations and model calculations, was 20 and 15%, respectively, which confirms global warming. The maximum contribution to the total dispersion of temperature, ice cover of the Barents Sea, AMO, introduces variability with periods of more than 20 years and trends that are 47, 20, 51% and 33, 57, 30%, respectively. On the basis of the cross correlation analysis,  significant links have been established between the ice extent of the Barents Sea, AMO, and North Atlantic Oscillation (NAO) for the  period 1900–2014. A significant negative connection (R = −0.8) of ice cover and Atlantic multi-decadal oscillations was revealed at periods of more than 20 years with a shift of 1–2 years; NAO and ice cover (R = −0.6) with a shift of 1–2 years for periods of 10–20 years; AMO and NAO (R = −0.4 ÷ −0.5) with a 3‑year shift with AMO leading at 3–4, 6–8 and more than 20 years. The periods of the ice cover growth are specified: 1950–1980 and the reduction of the ice cover: the 1920–1950 and the 1980–2010 in the Barents Sea. Intensification of the transfer of warm waters from the North Atlantic to the Arctic basin, under the atmospheric influence caused by the NAO, accompanied by the growth of AMO leads to an increase in temperature, salinity and a decrease of ice cover in the Barents Sea. During periods of ice cover growth, opposite tendencies appear. The decrease in the ice cover area of the entire Northern Hemisphere by 1.5 × 106 km2 since the mid-1980s. to the beginning of the 2010, identified in the present work on NOAA satellite data, confirms the results obtained on the change in ice extent in the Barents Sea.

Impact of wave-induced sea ice fragmentation on sea ice dynamics in the MIZ

2020 ◽  
Author(s):  
Guillaume Boutin ◽  
Timothy Williams ◽  
Pierre Rampal ◽  
Einar Olason ◽  
Camille Lique
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Ice Cover ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Sea Ice Extent ◽  
Ice Dynamics ◽  
Sea Ice Dynamics ◽  
Wave Induced ◽  
The Impact

&lt;p&gt;The decrease in Arctic sea ice extent is associated with an increase of the area where sea ice and open ocean interact, commonly referred to as the Marginal Ice Zone (MIZ). In this area, sea ice is particularly exposed to waves that can penetrate over tens to hundreds of kilometres into the ice cover. Waves are known to play a major role in the fragmentation of sea ice in the MIZ, and the interactions between wave-induced sea ice fragmentation and lateral melting have received particular attention in recent years. The impact of this fragmentation on sea ice dynamics, however, remains mostly unknown, although it is thought that fragmented sea ice experiences less resistance to deformation than pack ice. In this presentation, we will introduce a new coupled framework involving the spectral wave model WAVEWATCH III and the sea ice model neXtSIM, which includes a Maxwell-Elasto Brittle rheology. We use this coupled modelling system to investigate the potential impact of wave-induced sea ice fragmentation on sea ice dynamics. Focusing on the Barents Sea, we find that the decrease of the internal stress of sea ice resulting from its fragmentation by waves results in a more dynamical MIZ, in particular in areas where sea ice is compact. Sea ice drift is enhanced for both on-ice and off-ice wind conditions. Our results stress the importance of considering wave&amp;#8211;sea-ice interactions for forecast applications. They also suggest that waves likely modulate the area of sea ice that is advected away from the pack by ocean (sub-)mesoscale eddies near the ice edge, potentially contributing to the observed past, current and future sea ice cover decline in the Arctic.&amp;#160;&lt;/p&gt;

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