scholarly journals Does Arctic warming reduce preservation of organic matter in Barents Sea sediments?

2020 ◽  
Vol 378 (2181) ◽  
pp. 20190364 ◽  
Author(s):  
Johan C. Faust ◽  
Mark A. Stevenson ◽  
Geoffrey D. Abbott ◽  
Jochen Knies ◽  
Allyson Tessin ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Sea Ice ◽  
Surface Sediments ◽  
Barents Sea ◽  
Ice Cover ◽  
Atlantic Water ◽  
Sea Surface ◽  
Arctic Warming ◽  
Reactive Iron ◽  
The Barents Sea

Over the last few decades, the Barents Sea experienced substantial warming, an expansion of relatively warm Atlantic water and a reduction in sea ice cover. This environmental change forces the entire Barents Sea ecosystem to adapt and restructure and therefore changes in pelagic–benthic coupling, organic matter sedimentation and long-term carbon sequestration are expected. Here we combine new and existing organic and inorganic geochemical surface sediment data from the western Barents Sea and show a clear link between the modern ecosystem structure, sea ice cover and the organic carbon and CaCO 3 contents in Barents Sea surface sediments. Furthermore, we discuss the sources of total and reactive iron phases and evaluate the spatial distribution of organic carbon bound to reactive iron. Consistent with a recent global estimate we find that on average 21.0 ± 8.3 per cent of the total organic carbon is associated to reactive iron (fOC-Fe R ) in Barents Sea surface sediments. The spatial distribution of fOC-Fe R , however, seems to be unrelated to sea ice cover, Atlantic water inflow or proximity to land. Future Arctic warming might, therefore, neither increase nor decrease the burial rates of iron-associated organic carbon. However, our results also imply that ongoing sea ice reduction and the associated alteration of vertical carbon fluxes might cause accompanied shifts in the Barents Sea surface sedimentary organic carbon content, which might result in overall reduced carbon sequestration in the future. This article is part of the theme issue ‘The changing Arctic Ocean: consequences for biological communities, biogeochemical processes and ecosystem functioning’.

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.

Benthic Cycling of Phosphate in the changing Arctic Ocean

2021 ◽  
Author(s):  
Constance Lefebvre ◽  
Felipe S. Freitas ◽  
Katharine Hendry ◽  
Sandra Arndt
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Primary Productivity ◽  
Barents Sea ◽  
Atlantic Water ◽  
Iron Cycling ◽  
Reactive Iron ◽  
The Barents Sea ◽  
P Cycling ◽  
Model Approach

<p>The Arctic Ocean is currently experiencing rapid oceanographic shifts and significant sea-ice loss as a result of regional atmospheric and oceanic warming. The Barents Sea is a notable example of these phenomena, having seen a near 40% decline of its April sea-ice extent since 1979, and a progressive northward expansion of Atlantic Water (i.e., Atlantification). Such changes affect primary productivity and nutrient cycling in ways that remain poorly understood. Longer ice-free periods and the inflow of warmer Atlantic Water are expected to lead to extended bloom seasons on short, near-future timescales and therefore increase nutrient uptake in upper water layers. The benthic recycling of nutrients is believed to play an important part in replenishing nutrient inventories in overlying waters thus maintaining high primary productivity over the continuously expanding growth season. Therefore, it is crucial to increase our understanding of nutrient dynamic controls in changing oceans to make more accurate predictions and decipher the complex feedbacks involved in these evolving environments. However, most efforts to constrain and quantify nutrient fluxes so far have been directed at silicon, nitrogen or iron. This study aims to provide specific insight into phosphorus (P) cycling through its response to OM fluctuations and coupling with iron cycling. An integrated data-model approach was used to investigate the dynamics of P cycling at the sediment-water interface across five locations along the 30°E meridian that were drilled in the framework of the ChAOS project in the Barents Sea. The model approach allowed to explore the sensitivity of P cycling to plausible ranges of reactive iron and OM inputs. Greater inputs of reactive iron were found to decrease benthic phosphate fluxes (J<sub>PO4</sub>) whereas greater inputs of OM increased phosphate return to the water column. The quality of these inputs is equally significant: J<sub>PO4 </sub>decreased when iron hydroxides were made more reactive and increased with more reactive OM. Our findings indicate that variation in climatically sensitive processes, such as burial of terrestrial sediments and iron cycling, could represent powerful feedbacks on J<sub>PO4</sub> through adsorption/desorption mechanisms. Results also reveal significant oceanographic controls on J<sub>PO4</sub>, suggesting Atlantification of the Barents Sea will play into future phosphate availability.</p>

Relationships between wintertime sea ice cover in the Barents Sea and ocean temperature anomalies in the era of satellite observations

2020 ◽  
pp. 1-65
Author(s):  
Pawel Schlichtholz
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Early Period ◽  
Ice Cover ◽  
Atlantic Water ◽  
The Arctic ◽  
Ocean Temperature ◽  
Temperature Anomalies ◽  
The Barents Sea ◽  
Skill Scores

AbstractInvestigation of the predictability of sea ice cover in the Barents Sea is of paramount importance since sea ice changes in this part of the Arctic not only affect local marine ecosystems and human activities but may also influence weather and climate in northern mid-latitudes. Here, observational data from the period 1981-2018 are used to identify statistical linkages of wintertime sea ice cover in the Barents Sea region to preceding sea surface temperature (SST) and Atlantic water temperature anomalies in that region. We find that the ocean temperature anomalies formed by local air-sea interactions during the winter-to-spring season are a significant source of predictability for sea ice area (SIA) in the Barents Sea region the following winter. Optimal areas for constructing SST predictors of Barents Sea SIA and skill scores from retrospective statistical forecasts are shown to differ between the periods to and since the onset of rapid sea ice decline in the region. In the EARLY period (1982-2003), springtime SSTs in the western Barents Sea predicted 44% of the variance of the following winter Barents Sea SIA. In the LATE period (2003-2017), springtime SSTs in the southern Barents Sea predicted 70% of the variance of the following winter Barents Sea SIA. Regression analysis suggests that feedbacks from anomalous winds may be important for the predictability of wintertime sea ice cover in the Barents Sea region.

Postglacial paleoceanography and paleoenvironments in the northwestern Barents Sea

2019 ◽  
Vol 92 (2) ◽  
pp. 430-449 ◽  
Author(s):  
Elena Ivanova ◽  
Ivar Murdmaa ◽  
Anne de Vernal ◽  
Bjørg Risebrobakken ◽  
Alexander Peyve ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Sediment Cores ◽  
Ice Cover ◽  
Atlantic Water ◽  
The Arctic ◽  
High Productivity ◽  
Surface Warming ◽  
The Barents Sea ◽  
Suitable Location

AbstractThe Barents Sea offers a suitable location for documenting advection of warm and saline Atlantic Water (AW) into the Arctic and its impact on deglaciation and postglacial conditions. We investigate the timing, succession, and mechanisms of the transition from proximal glaciomarine to marine environment in the northwestern Barents Sea. Two studied sediment cores demonstrate diachronous retreat of the grounded ice sheet from the Kvitøya Trough (core S2528) to Erik Eriksen Trough (core S2519). Oxygen isotope records from core S2528 depict a two-step pattern, with lower δ18O values prior to the Younger Dryas (YD), and higher values afterward because of advection of the more saline, 18O-enriched AW. At this location, subsurface AW penetration increased during the Allerød and YD/Preboreal transition. In the study area, foraminiferal and dinocyst data from the YD interval suggest cold conditions, extensive sea-ice cover, and brine formation, along with the flow of chilled AW at subsurface and the development of a high-productivity polynya in the Erik Eriksen Trough. Dense winter sea-ice cover with seasonal productivity persisted in the Kvitøya Trough area during the early Holocene, whereas surface warming seems to have occurred during the middle Holocene interval.

scholarly journals Wind-Driven Atlantic Water Flow as a Direct Mode for Reduced Barents Sea Ice Cover

2017 ◽  
Vol 30 (2) ◽  
pp. 803-812 ◽  
Author(s):  
Vidar S. Lien ◽  
Pawel Schlichtholz ◽  
Øystein Skagseth ◽  
Frode B. Vikebø
Keyword(s):  
Sea Ice ◽  
Heat Transport ◽  
Ocean Circulation ◽  
Barents Sea ◽  
Heat Content ◽  
Circulation Model ◽  
Ice Cover ◽  
Atlantic Water ◽  
Direct Role ◽  
The Barents Sea

Variability in the Barents Sea ice cover on interannual and longer time scales has previously been shown to be governed by oceanic heat transport. Based on analysis of observations and results from an ocean circulation model during an event of reduced sea ice cover in the northeastern Barents Sea in winter 1993, it is shown that the ocean also plays a direct role within seasons. Positive wind stress curl and associated Ekman divergence causes a coherent increase in the Atlantic water transport along the negative thermal gradient through the Barents Sea. The immediate response connected to the associated local winds in the northeastern Barents Sea is a decrease in the sea ice cover due to advection. Despite a subsequent anomalous ocean-to-air heat loss on the order of 100 W m−2 due to the open water, the increase in the ocean heat content caused by the circulation anomaly reduced refreezing on a time scale of order one month. Furthermore, it is found that coherent ocean heat transport anomalies occurred more frequently in the latter part of the last five decades during periods of positive North Atlantic Oscillation index, coinciding with the Barents Sea winter sea ice cover decline from the 1990s and onward.

scholarly journals Paleo Cruise 2018

2020 ◽  
Author(s):  
Katrine Husum ◽  
Ulysses Ninnemann ◽  
Tom Arne Rydningen ◽  
Elisabeth Alve ◽  
Naima E B Altuna ◽  
...  
Keyword(s):  
Sea Ice ◽  
Time Scales ◽  
Barents Sea ◽  
Sediment Cores ◽  
Ice Cover ◽  
Atlantic Water ◽  
Natural Variability ◽  
Argo Float ◽  
The Barents Sea ◽  
Through Flow

The Nansen Legacy paleo cruise was carried out from September 26 to October 20, 2018 with RV “Kronprins Haakon”. The cruise took place in the northern Barents Sea and the Nansen Basin, and it went through the sea ice to 83.3 N. The overriding objective of the cruise was to reconstruct the natural variability and range of sea ice cover and Atlantic Water through flow in the Barents Sea on longer time scales. During the cruise four ocean moorings were deployed in northwest Barents Sea, where one ARGO float was also deployed. Twelve “paleo stations” were identified using multibeam and sub bottom profilers. At these stations, short and long sediment cores were obtained. This cruise report gives an overview of methods used and samples taken. 

Sea surface wind and Sea ice in the Barents Sea using microwave sensing data from Meteor-M N1 and GCOM-W1 satellites in January–March 2013

2016 ◽  
Vol 52 (9) ◽  
pp. 1041-1050 ◽  
Author(s):  
L. M. Mitnik ◽  
M. L. Mitnik ◽  
G. M. Chernyavsky ◽  
I. V. Cherny ◽  
A. V. Vykochko ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Surface Wind ◽  
Sea Surface ◽  
Sensing Data ◽  
Sea Surface Wind ◽  
The Barents Sea

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 Atlantic Water advection vs glacier dynamics in northern Spitsbergen since early deglaciation

2017 ◽  
Author(s):  
Martin Bartels ◽  
Jürgen Titschack ◽  
Kirsten Fahl ◽  
Rüdiger Stein ◽  
Marit-Solveig Seidenkrantz ◽  
...  
Keyword(s):  
Sea Ice ◽  
Environmental Conditions ◽  
Late Holocene ◽  
Ice Cover ◽  
Atlantic Water ◽  
Sea Surface ◽  
Early Holocene ◽  
Sea Surface Temperatures ◽  
Surface Temperatures ◽  
Glacier Dynamics

Abstract. Atlantic Water (AW) advection plays an important role for climatic, oceanographic and environmental conditions in the eastern Arctic. Situated along the only deep connection between the Atlantic and the Arctic Ocean, the Svalbard Archipelago is an ideal location to reconstruct the past AW advection history and document its linkage with local glacier dynamics, as illustrated in the present study of a sedimentary record from Woodfjorden (northern Spitsbergen) spanning the last ~ 15 500 years. Sedimentological, micropalaeontological and geochemical analyses were used to reconstruct changes in marine environmental conditions, sea-ice cover and glacier activity. Data illustrate a partial breakup of the Svalbard–Barents–Sea Ice Sheet from Heinrich Stadial 1 onwards (until ~ 14.6 ka BP). During the Bølling-Allerød (~ 14.6–12.7 ka BP), AW penetrated as a bottom water mass into the fjord system and contributed significantly to the destabilisation of local glaciers. During the Younger Dryas (~ 12.7–11.7 ka BP), it intruded into intermediate waters while evidence for a glacier advance is lacking. A short-term deepening of the halocline occurred at the very end of this interval. During the early Holocene (~ 11.7–7.8 ka BP), mild conditions led to glacier retreat, a reduced sea-ice cover and increasing sea surface temperatures, with a brief interruption during the Preboreal Oscillation (~ 11.1–10.8 ka BP). During the late Holocene (~ 1.8–0.4 ka BP), a slightly reduced AW inflow and lower sea surface temperatures compared to the early Holocene are reconstructed. Glaciers, which previously retreated to the shallower inner parts of the Woodfjorden system, likely advanced during the late Holocene. In particular, as topographic control in concert with the reduced summer insolation partly decoupled glacier dynamics from AW advection during this recent interval.

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