Nutrient Distributions in the Canadian Archipelago: Indicators of Summer Water Mass and Flow Characteristics

1980 ◽  
Vol 37 (4) ◽  
pp. 589-599 ◽  
Author(s):  
E. P. Jones ◽  
A. R. Coote
Keyword(s):  
Surface Layer ◽  
Arctic Ocean ◽  
Water Mass ◽  
Flow Characteristics ◽  
Ocean Surface ◽  
The Arctic ◽  
Phosphate Nitrate ◽  
Canadian Basin ◽  
Mass Identification ◽  
Ocean Surface Layer

Concentrations of the nutrients, phosphate, nitrate, and silicate, were measured at several locations in Lancaster Sound, Jones Sound, and Smith Sound. Arctic Ocean surface layer water flowing out through Lancaster Sound and Jones Sound have higher phosphate and silicate concentrations than that flowing out through Smith Sound. Phosphate and silicate concentrations can be useful to indicate flow patterns within some regions of the Canadian Archipelago and to delineate partially the gyre in the Canadian Basin of the Arctic Ocean.Key words: nutrients: phosphate, nitrate, silicate; distribution: Arctic, Canadian Archipelago; water mass, identification, mixing

scholarly journals Interannual variability of parameters of the Arctic Ocean surface layer and halocline

2020 ◽  
Vol 66 (4) ◽  
pp. 404-426
Author(s):  
E. A. Cherniavskaia ◽  
L. A. Timokhov ◽  
V. Y. Karpiy ◽  
S. Y. Malinovskiy
Keyword(s):  
Surface Layer ◽  
Arctic Ocean ◽  
Interannual Variability ◽  
Ocean Surface ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Ocean Surface Layer

scholarly journals Horizontal Density Structure and Restratification of the Arctic Ocean Surface Layer

2012 ◽  
Vol 42 (4) ◽  
pp. 659-668 ◽  
Author(s):  
Mary-Louise Timmermans ◽  
Sylvia Cole ◽  
John Toole
Keyword(s):  
Surface Layer ◽  
Arctic Ocean ◽  
Baroclinic Instability ◽  
Ocean Surface ◽  
The Arctic ◽  
Density Structure ◽  
Buoyancy Forcing ◽  
Convective Mixing ◽  
The Arctic Ocean ◽  
Ocean Surface Layer

Abstract Ice-tethered profiler (ITP) measurements from the Arctic Ocean’s Canada Basin indicate an ocean surface layer beneath sea ice with significant horizontal density structure on scales of hundreds of kilometers to the order 1 km submesoscale. The observed horizontal gradients in density are dynamically important in that they are associated with restratification of the surface ocean when dense water flows under light water. Such restratification is prevalent in wintertime and competes with convective mixing upon buoyancy forcing (e.g., ice growth and brine rejection) and shear-driven mixing when the ice moves relative to the ocean. Frontal structure and estimates of the balanced Richardson number point to the likelihood of dynamical restratification by isopycnal tilt and submesoscale baroclinic instability. Based on the evidence here, it is likely that submesoscale processes play an important role in setting surface-layer properties and lateral density variability in the Arctic Ocean.

scholarly journals Diversity and biogeography of SAR11 bacteria from the Arctic Ocean

2019 ◽  
Author(s):  
Susanne Kraemer ◽  
Arthi Ramachandran ◽  
David Colatriano ◽  
Connie Lovejoy ◽  
David A. Walsh
Keyword(s):  
Surface Layer ◽  
Arctic Ocean ◽  
Adaptive Evolution ◽  
Brackish Water ◽  
Water Mass ◽  
The Arctic ◽  
High Latitudes ◽  
Bacterial Group ◽  
The Arctic Ocean ◽  
Globally Distributed

AbstractThe Arctic Ocean is relatively isolated from other oceans and consists of strongly stratified water masses with distinct histories, nutrient, temperature and salinity characteristics, therefore providing an optimal environment to investigate local adaptation. The globally distributed SAR11 bacterial group consists of multiple ecotypes that are associated with particular marine environments, yet relatively little is known about Arctic SAR11 diversity. Here, we examined SAR11 diversity using ITS analysis and metagenome-assembled genomes (MAGs). Arctic SAR11 assemblages were comprised of the S1a, S1b, S2, and S3 clades, and structured by water mass and depth. The fresher surface layer was dominated by an ecotype (S3-derived P3.2) previously associated with Arctic and brackish water. In contrast, deeper waters of Pacific origin were dominated by the P2.3 ecotype of the S2 clade, within which we identified a novel subdivision (P2.3s1) that was rare outside the Arctic Ocean. Arctic S2-derived SAR11 MAGs were restricted to high latitudes and included MAGs related to the recently defined S2b subclade, a finding consistent with bi-polar ecotypes and Arctic endemism. These results place the stratified Arctic Ocean into the SAR11 global biogeography and have identified SAR11 lineages for future investigation of adaptive evolution in the Arctic Ocean.

Stable isotopes in planktonic and benthic foraminifera from Arctic Ocean surface sediments

1988 ◽  
Vol 25 (5) ◽  
pp. 701-709 ◽  
Author(s):  
A. E. Aksu ◽  
G. Vilks
Keyword(s):  
Surface Water ◽  
Arctic Ocean ◽  
Sea Water ◽  
Ocean Surface ◽  
The Arctic ◽  
Size Fractions ◽  
Isotopic Compositions ◽  
Isotopic Analyses ◽  
Stable Isotopic ◽  
Surface Water Salinity

Oxygen and carbon isotopic analyses have been performed on the tests of Planulina wuellerstorfi and three size fractions of sinistral Neogloboquadrina pachyderma recovered from 33 Arctic Ocean surface-sediment samples. Stable isotopic compositions of N. pachyderma are found to be dependent on the test size: larger specimens show considerable enrichment in both δ18O and δ18C. The difference between the isotopic compositions of the 63–125 and 125–250 μm size fractions in N. pachyderma can be explained by biogenic fractionation effects during foraminiferal test growth. Larger (250–500 μm) N. pachyderma displayed accretions of secondary calcite, i.e., the outermost shell contained significant amounts of inorganically precipitated magnesium calcite. Thus, larger foraminifera may not be suited for down-core stable isotopic studies. There is a difference of ~2‰ between δ18O values of surface samples from the eastern and western Arctic Ocean, reflecting large differences between surface-water salinity in these regions. Therefore, oxygen isotopic data may have limited use as a chronostratigraphic tool in down-core studies in the Arctic Ocean, but we can use them to infer past variations in surface-water salinities. Planulina wuellerstorfi also showed depletions of both δ18O and δ18C in its calcite tests relative to calcite precipitated in isotopic equilibrium with ambient sea water; these depletions ranged from −0.8 to −0.9‰ in δ18Oand −1.2 to −0.9‰ in δ18C. This taxon is found to deposit its shell very close to the δ18C of ΣCO2 of bottom waters.

Methane oxidation and methane fluxes in the ocean surface layer and deep anoxic waters

Nature ◽  
1987 ◽  
Vol 327 (6119) ◽  
pp. 226-229 ◽  
Author(s):  
B. B. Ward ◽  
K. A. Kilpatrick ◽  
P. C. Novelli ◽  
M. I. Scranton
Keyword(s):  
Surface Layer ◽  
Methane Oxidation ◽  
Ocean Surface ◽  
Anoxic Waters ◽  
Methane Fluxes ◽  
Ocean Surface Layer

MOSAiC simulator in CMIP6

2021 ◽  
Author(s):  
Rajka Juhrbandt ◽  
Suvarchal Cheedela ◽  
Nikolay Koldunov ◽  
Thomas Jung
Keyword(s):  
Surface Layer ◽  
Arctic Ocean ◽  
Ease Of Use ◽  
Arctic Climate ◽  
The Arctic ◽  
Early Results ◽  
The Arctic Ocean ◽  
Virtual Field ◽  
Field Campaigns ◽  
Type Code

<p>The recently completed Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) can serve as reference to evaluate current and future ocean state of the Arctic Ocean. With this premise, we perform a virtual MOSAiC expedition in historical and ssp370-scenario experiments in data generated by CMIP6 models.<br><br>The timespan covered ranges from preindustrial times (1851-1860) through present-day up to a 4K world (2091-2100). Early results using AWI-CM model, suggest that for scenario simulations a thinning of the colder surface layer and a warming of the layer between 200 and 1200 m along the MOSAiC path can be expected, while there is no significant change in temperature below this depth. Results from other models will be presented.<br><br>The Python-centric tool used for the analysis simplifies preprocessing of a pool of CMIP6 data and selecting data on space-time trajectory. It exposes an interface that is agnostic to underlying model or its grid type. Code snippets are presented along to demonstrate the tool's ease of use with a hope to inspire such virtual field campaigns using other past observations or arbitrary trajectories.</p>

scholarly journals A Diagnostic Model of the Nordic Seas and Arctic Ocean Circulation: Quantifying the Effects of a Variable Bottom Density along a Sloping Topography

2008 ◽  
Vol 38 (12) ◽  
pp. 2685-2703 ◽  
Author(s):  
Signe Aaboe ◽  
Ole Anders Nøst
Keyword(s):  
Arctic Ocean ◽  
Ocean Circulation ◽  
Large Scale ◽  
The Arctic ◽  
Diagnostic Model ◽  
Large Scale Circulation ◽  
Nordic Seas ◽  
Variable Bottom ◽  
Canadian Basin ◽  
Baroclinic Transport

Abstract A linear diagnostic model, solving for the time-mean large-scale circulation in the Nordic seas and Arctic Ocean, is presented. Solutions on depth contours that close within the Nordic seas and Arctic Ocean are found from vorticity balances integrated over the areas enclosed by the contours. Climatological data for wind stress and hydrography are used as input to the model, and the bottom geostrophic flow is assumed to follow depth contours. Comparison against velocity observations shows that the simplified dynamics in the model capture many aspects of the large-scale circulation. Special attention is given to the dynamical effects of an along-isobath varying bottom density, which leads to a transformation between barotropic and baroclinic transport. Along the continental slope, enclosing both the Nordic seas and Arctic Ocean, the along-slope barotropic transport has a maximum in the Nordic seas and a minimum in the Canadian Basin with a difference of 9 Sv (1 Sv ≡ 106 m3 s−1) between the two. This is caused by the relatively lower bottom densities in the Canadian Basin compared to the Nordic seas and suggests that most of the barotropic transport entering the Arctic Ocean through the Fram Strait is transformed to baroclinic transport. A conversion from barotropic to baroclinic flow may be highly important for the slope–basin exchange in the Nordic seas and Arctic Ocean. The model has obvious shortcomings due to its simplicity. However, the simplified physics and the agreement with observations make this model an excellent framework for understanding the large-scale circulation in the Nordic seas and Arctic Ocean.

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