Modelled Stokes drift in the Marginal ice zones of the Arctic Ocean

2020 ◽  
Author(s):  
Jingkai Li
Keyword(s):  
Arctic Ocean ◽  
Chukchi Sea ◽  
Surface Current ◽  
Reanalysis Data ◽  
Stokes Drift ◽  
The Arctic ◽  
Bulk Wave ◽  
Wave Parameters ◽  
The Arctic Ocean ◽  
Ice Floes

<p>The Stokes drift in the marginal ice zones (MIZ) of the Arctic Ocean is modelled by WAVEWATCH III. Applying two viscoelastic and one empirical frequency-dependent wave-ice models, the modelled wave parameters and spectrum are compared with field observations in the Beaufort-Chukchi Sea. Three wave-ice parameterizations show similar abilities to produce the surface Stokes drift estimated from buoy measurements. By using five-year (2015-2019) hindcasted directional spectra of the autumn Arctic, we present and discuss the monthly mean surface Stokes drift (1-10 cm/s), e-folding depth (1-14 m) and vertically integrated transport (0.1-0.4 m2/s) in the marginal ice zones, which are stronger in October than in September. When bulk wave parameters are adopted to estimate the Stokes drift fields, the surface Stokes drift will be underestimated by about 44-59% with mean ice concentration smaller than 60%, and the Stokes e-folding depth will be overestimated by about 1.4 to 5.0 times increasing from the interior to the edge of the ice cover. Since the Stokes drift may be an important component of the total surface current, we compare the modelled surface Stokes drift with the Eulerian current from reanalysis data, which shows that the mean surface Stokes drift is typically about 30% of the Eulerian current over large parts of the MIZ in Arctic Ocean, and is of the same order or even larger in some sea areas of the Chukchi, E. Siberian and Laptev Seas. It indicates that the Stokes drift is necessary to be considered to better model the dynamic processes of the sea ice, especially for the drift of ice floes.</p>

Supplementary material to "The 3.6 ka Aniakchak tephra in the Arctic Ocean: a constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea"

2016 ◽  
Author(s):  
Christof Pearce ◽  
Aron Varhelyi ◽  
Stefan Wastegård ◽  
Francesco Muschitiello ◽  
Natalia Barrientos ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Chukchi Sea ◽  
The Arctic ◽  
The Holocene ◽  
The Arctic Ocean ◽  
Supplementary Material ◽  
Reservoir Age

Dissolved Neodymium Isotopes Trace Origin and Spatiotemporal Evolution of Modern Arctic Sea Ice

2020 ◽  
Author(s):  
Georgi Laukert ◽  
Dorothea Bauch ◽  
Ilka Peeken ◽  
Thomas Krumpen ◽  
Kirstin Werner ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Surface Waters ◽  
Ice Cores ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Spatiotemporal Evolution ◽  
Arctic Sea ◽  
The Arctic Ocean ◽  
Ice Floes

<p>The lifetime and thickness of Arctic sea ice have markedly decreased in the recent past. This affects Arctic marine ecosystems and the biological pump, given that sea ice acts as platform and transport medium of marine and atmospheric nutrients. At the same time sea ice reduces light penetration to the Arctic Ocean and restricts ocean/atmosphere exchange. In order to understand the ongoing changes and their implications, reconstructions of source regions and drift trajectories of Arctic sea ice are imperative. Automated ice tracking approaches based on satellite-derived sea-ice motion products (e.g. ICETrack) currently perform well in dense ice fields, but provide limited information at the ice edge or in poorly ice-covered areas. Radiogenic neodymium (Nd) isotopes (ε<sub>Nd</sub>) have the potential to serve as a chemical tracer of sea-ice provenance and thus may provide information beyond what can be expected from satellite-based assessments. This potential results from pronounced ε<sub>Nd</sub> differences between the distinct marine and riverine sources, which feed the surface waters of the different sea-ice formation regions. We present the first dissolved (< 0.45 µm) Nd isotope and concentration data obtained from optically clean Arctic first- and multi-year sea ice (ice cores) collected from different ice floes across the Fram Strait during the RV POLARSTERN cruise PS85 in 2014. Our data confirm the preservation of the seawater ε<sub>Nd</sub>signatures in sea ice despite low Nd concentrations (on average ~ 6 pmol/kg) resulting from efficient brine rejection. The large range in ε<sub>Nd</sub> signatures (~ -10 to -30) mirrors that of surface waters in various parts of the Arctic Ocean, indicating that differences between ice floes but also between various sections in an individual ice core reflect the origin and evolution of the sea ice over time. Most ice cores have ε<sub>Nd</sub> signatures of around -10, suggesting that the sea ice was formed in well-mixed waters in the central Arctic Ocean and transported directly to the Fram Strait via the Transpolar Drift. Some ice cores, however, also revealed highly unradiogenic signatures (ε<sub>Nd</sub> < ~ -15) in their youngest (bottom) sections, which we attribute to incorporation of meltwater from Greenland into newly grown sea ice layers. Our new approach facilitates the reconstruction of the origin and spatiotemporal evolution of isolated sea-ice floes in the future Arctic.</p>

Algal bloom in a melt pond on Canada Basin pack ice

Polar Record ◽  
2015 ◽  
Vol 52 (1) ◽  
pp. 114-117 ◽  
Author(s):  
Ling Lin ◽  
Jianfeng He ◽  
Fang Zhang ◽  
Shunan Cao ◽  
Can Zhang
Keyword(s):  
Arctic Ocean ◽  
Algal Bloom ◽  
Canada Basin ◽  
The Arctic ◽  
Arctic Warming ◽  
Melt Pond ◽  
Melt Ponds ◽  
Pack Ice ◽  
The Arctic Ocean ◽  
Ice Floes

ABSTRACTMelt ponds are common on the surface of ice floes in the Arctic Ocean during spring and summer. Few studies on melt pond algae communities have been accomplished. These studies have shown that these melt ponds were ultra-oligotrophic, and contribute little to overall productivity. However, during the 6th Chinese Arctic Cruise in the Arctic Ocean in summer 2014, a closed coloured melt pond with a chlorophyll a concentration of 15.32 μg/L was observed on Arctic pack ice in the Canada Basin. The bloom was caused by the chlorophyte Carteria lunzensis at an abundance of 15.49×106 cells/L and biomass of 5.07 mg C/L. Primary production within surface melt ponds may need more attention along with Arctic warming.

scholarly journals On the circulation, water mass distribution, and nutrient concentrations of the western Chukchi Sea

Ocean Science ◽  
2022 ◽  
Vol 18 (1) ◽  
pp. 29-49
Author(s):  
Jaclyn Clement Kinney ◽  
Karen M. Assmann ◽  
Wieslaw Maslowski ◽  
Göran Björk ◽  
Martin Jakobsson ◽  
...  
Keyword(s):  
Numerical Modelling ◽  
Arctic Ocean ◽  
Dissolved Inorganic Carbon ◽  
Chukchi Sea ◽  
The Arctic ◽  
Sediment Surface ◽  
Nutrient Concentrations ◽  
Bering Strait ◽  
East Siberian Sea ◽  
The Arctic Ocean

Abstract. Substantial amounts of nutrients and carbon enter the Arctic Ocean from the Pacific Ocean through the Bering Strait, distributed over three main pathways. Water with low salinities and nutrient concentrations takes an eastern route along the Alaskan coast, as Alaskan Coastal Water. A central pathway exhibits intermediate salinity and nutrient concentrations, while the most nutrient-rich water enters the Bering Strait on its western side. Towards the Arctic Ocean, the flow of these water masses is subject to strong topographic steering within the Chukchi Sea with volume transport modulated by the wind field. In this contribution, we use data from several sections crossing Herald Canyon collected in 2008 and 2014 together with numerical modelling to investigate the circulation and transport in the western part of the Chukchi Sea. We find that a substantial fraction of water from the Chukchi Sea enters the East Siberian Sea south of Wrangel Island and circulates in an anticyclonic direction around the island. This water then contributes to the high-nutrient waters of Herald Canyon. The bottom of the canyon has the highest nutrient concentrations, likely as a result of addition from the degradation of organic matter at the sediment surface in the East Siberian Sea. The flux of nutrients (nitrate, phosphate, and silicate) and dissolved inorganic carbon in Bering Summer Water and Winter Water is computed by combining hydrographic and nutrient observations with geostrophic transport referenced to lowered acoustic Doppler current profiler (LADCP) and surface drift data. Even if there are some general similarities between the years, there are differences in both the temperature–salinity and nutrient characteristics. To assess these differences, and also to get a wider temporal and spatial view, numerical modelling results are applied. According to model results, high-frequency variability dominates the flow in Herald Canyon. This leads us to conclude that this region needs to be monitored over a longer time frame to deduce the temporal variability and potential trends.

A perfect bowl-like submesoscale vortex from seismic reflection transect in the Chukchi Sea, Arctic Ocean

2021 ◽  
Author(s):  
Shun Yang ◽  
Haibin Song ◽  
Kun Zhang
Keyword(s):  
Arctic Ocean ◽  
Water Column ◽  
Chukchi Sea ◽  
The Arctic ◽  
Global Ocean ◽  
Physical Oceanography ◽  
Depth Range ◽  
Seismic Line ◽  
The Arctic Ocean ◽  
The Right

<p>The eddies are ubiquitous in the ocean and play an important role in the transportation and redistribution of heat, salt, carbon, nutrients and other materials in the global ocean, thus can regulate global climate and affect the distribution of marine organism. Compared with mesoscale eddies, submesoscale vortices (SVs) have smaller spatial and temporal scales, which impose higher requirements on observation and simulation. The oceanic SVs have a strong vertical velocity, which provides an important supply of nutrients in the upper ocean.</p><p>Many researchers have studied the SVs in the Arctic Ocean by physical oceanography methods (e.g., <em>in-situ </em>measurements and satellite observations). Here, we found a perfect bowl-like SV using a new method named seismic oceanography (SO). SO can use multichannel seismic (MCS) reflection data to produce surprisingly detailed images of water column. Compared with the traditional physical oceanography methods, SO has the advantages of high acquisition efficiency, high lateral resolution (~10 m) and full depth imaging of seawater.</p><p>We used MCS data to image the water column in the in autumn Northeast Chukchi Sea, and captured a perfect bowl-like structure with a depth range of ~200-620m. The structure is almost bilaterally symmetric and has dip angles of 4.8° and 5.5° on the left and on the right, respectively. And it has a horizontal scale of about 12 km at the top and 4.5 km at the bottom, and both the top and bottom of it are near horizontal. The reflections are almost blank in its interior, but are intense and very narrow (~30 m thick) at the lateral boundaries. This indicated that the interior water is homogeneous and quite different from that around it. Fortunately, there is an XBT station near the seismic line and collected almost simultaneously (only one day apart) with the seismic line. The XBT station shows obvious high temperature anomaly over 2°C at the depth of 210-700 m. Therefore, we concluded the structure is a subsurface warm SV, i.e. anticyclonic warm eddy, and may be a submesoscale coherent vortex (SCV). The anomalies from the surrounding water masses indicate that the SV was created at the edge of the Arctic Ocean and then advected here.</p><p>In addition, we used Rossby number (Ro) and Okubo-Weiss (OW) parameter calculated from daily-averaged re-analysis hydrographic data (~3.5 km of grid spacing at 75°N ) from Copernicus Marine Environment Monitoring Service (CMEMS) to analyze the SV. Result shows that the values of the Ro and OW parameter in the area of the SV are both negative. This also suggests that this SV is an anticyclone. This submesoscale anticyclonic vortex may be generated from the friction effect between the warm inflow from the North Pacific and the right wall of Barrow Canyon after passing through the Bering Strait, and then transported to the Northeast of Chukchi Sea by the Beaufort Gyre.</p>

Oceanographic Features of the Canadian Archipelago

1957 ◽  
Vol 14 (5) ◽  
pp. 731-769 ◽  
Author(s):  
W. B. Bailey
Keyword(s):  
Arctic Ocean ◽  
Beaufort Sea ◽  
The Arctic ◽  
Temperature Structure ◽  
Vertical Temperature ◽  
Baffin Bay ◽  
The North ◽  
The Arctic Ocean ◽  
North Water ◽  
Ice Floes

Oceanographic data collected during the first cruise of H.M.C.S. Labrador to the Canadian Arctic in August and September 1954 permit comparisons of the vertical temperature and salinity structures in Baffin Bay, the Canadian Archipelago and the Arctic Ocean. From a comparison of the temperature–salinity characteristics of the waters in the Arctic Ocean (Beaufort Sea) with those in Baffin Bay, it is found that: (a) the surface waters of the Arctic Ocean are much less saline than those in Baffin Bay, but minimum temperatures are the same (−1.8 °C), (b) the waters of the upper 200 m. in Baffin Bay are denser than those found at corresponding depths in the Arctic Ocean, (c) below 200 m., Arctic waters are the denser, and below 500 m. they are denser than any waters found in Baffin Bay, and (d) waters found at 250 m. in the Beaufort Sea, at 500 m. in Smith Sound, and at 1250 m. in central Baffin Bay, have identical temperature and salinity characteristics (−0.3 °C., 34.4‰).In addition the data permitted limited investigations into the effect of drifting ice floes on the vertical temperature structure of the water, the origin of the "north water", long-term variations in the oceanographic conditions in Baffin Bay, and dynamic calculations of currents and volume transports of the waters through the channels leading into Baffin Bay.

Modeled Stokes drift in the marginal ice zones of the Arctic Ocean

2021 ◽  
Author(s):  
Jingkai Li ◽  
Rui Li ◽  
Yang Ding ◽  
Yunrui Ma
Keyword(s):  
Arctic Ocean ◽  
Stokes Drift ◽  
The Arctic ◽  
The Arctic Ocean
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