Diatoms and aquatic palynomorphs in the sediments of the Eurasian Arctic seas and their significance for paleooceanological investigations in the Arctic

Author(s):  
Yelena I. Polyakova ◽  
Yekaterina I. Novichkova ◽  
Tatiana S. Klyuvitkina ◽  
Elizaveta A. Agafonova ◽  
Irina M. Kryukova

Presented the results of long-term studies of diatoms and aquatic palynomorphs in surface sediments of the Arctic seas and the possibility of their use for the reconstructions of paleocirculation water masses, advection of Atlantic and Bering sea water into the Arctic ocean, changes in the river runoff to the seas, sedimentary processes in the marginal filter of the largest rivers, seasonal sea ice cover and other hydrological parameters.

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Keiji Horikawa ◽  
Ellen E. Martin ◽  
Chandranath Basak ◽  
Jonaotaro Onodera ◽  
Osamu Seki ◽  
...  

ARCTIC ◽  
1961 ◽  
Vol 14 (3) ◽  
Author(s):  
L.K. Coachman ◽  
C.A. Barnes

2008 ◽  
pp. 405-425 ◽  
Author(s):  
Rüdiger Gerdes ◽  
Michael Karcher ◽  
Cornelia Köberle ◽  
Kerstin Fieg

2019 ◽  
Vol 59 (4) ◽  
pp. 544-552
Author(s):  
A. A. Vetrov ◽  
E. A. Romankevich

Particulate organic carbon (POC) is one of main component of carbon cycle in the Ocean. In this study an attempt to construct a picture of the distribution and fluxes of POC in the Arctic Ocean adjusting for interchange with the Pacific and Atlantic Oceans has been made. The specificity of this construction is associated with an irregular distribution of POC measurements and complicated structure and hydrodynamics of the waters masses. To overcome these difficulties, Multiple Linear Regression technic (MLR) was performed to test the significant relation between POC, temperature, salinity, as well depth, horizon, latitude and offshore distance. The mapping of POC distribution and its fluxes was carrying out at 38 horizons from 5 to 4150 m (resolution 1°×1°). Data on temperature, salinity, meridional and zonal components of current velocities were obtained from ORA S4 database (Integrated Climate Data Center, http://icdc.cen.uni-hamburg.de/las). The import-export of POC between the Arctic, Atlantic and Pacific Oceans as well as between Arctic Seas was precomputed by summer fluxes. The import of POC in the Arctic Ocean is estimated to be 38±8Tg Cyr-1, and the export is -9.5±4.4Tg Cyr-1.


2021 ◽  
Author(s):  
Elianne Egge ◽  
Stephanie Elferink ◽  
Daniel Vaulot ◽  
Uwe John ◽  
Gunnar Bratbak ◽  
...  

AbstractArctic marine protist communities have been understudied due to challenging sampling conditions, in particular during winter and in deep waters. The aim of this study was to improve our knowledge on Arctic protist diversity through the year, both in the epipelagic (< 200 m depth) and mesopelagic zones (200-1000 m depth). Sampling campaigns were performed in 2014, during five different months, to capture the various phases of the Arctic primary production: January (winter), March (pre-bloom), May (spring bloom), August (post-bloom) and November (early winter). The cruises were undertaken west and north of the Svalbard archipelago, where warmer Atlantic waters from the West Spitsbergen Current meets cold Arctic waters from the Arctic Ocean. From each cruise, station, and depth, 50 L of sea water were collected and the plankton was size-fractionated by serial filtration into four size fractions between 0.45-200 µm, representing the picoplankton, nanoplankton and microplankton. In addition vertical net hauls were taken from 50 m depth to the surface at selected stations. From the plankton samples DNA was extracted, the V4 region of the 18S rRNA-gene was amplified by PCR with universal eukaryote primers and the amplicons were sequenced by Illumina high-throughput sequencing. Sequences were clustered into Amplicon Sequence Variants (ASVs), representing protist genotypes, with the dada2 pipeline. Taxonomic classification was made against the curated Protist Ribosomal Reference database (PR2). Altogether 6,536 protist ASVs were obtained (including 54 fungal ASVs). Both ASV richness and taxonomic composition were strongly dependent on size-fraction, season, and depth. ASV richness was generally higher in the smaller fractions, and higher in winter and the mesopelagic samples than in samples from the well-lit epipelagic zone during summer. During spring and summer, the phytoplankton groups diatoms, chlorophytes and haptophytes dominated in the epipelagic zone. Parasitic and heterotrophic groups such as Syndiniales and certain dinoflagel-lates dominated in the mesopelagic zone all year, as well as in the epipelagic zone during the winter. The dataset is available at https://doi.org/10.17882/79823, (Egge et al., 2014).


2021 ◽  
Author(s):  
Elena Popova

&lt;p&gt;Such factors as climate, currents, morphology, riverine input, and the source rocks influence the composition of the sediments in the Arctic Ocean. Heavy minerals being quite inert in terms of transport can reflect the geology of the source rock clearly and indicate the riverine input. There is a long history of studying the heavy mineral composition of the sediments in the Arctic Ocean. The works by Vogt (1997), Kosheleva (1999), Stein (2008), and others study the distribution of the minerals both on a sea scale and oceanwide. The current study covers Russian shelf seas: Barents, Kara, Laptev, East Siberian, and Chukchi Seas. To collect the material several data sources were used: data collected by the institute VNIIOkeangeologia during numerous expeditions since 2000 for mapping the shelf, data from the old expedition reports (earlier than 2000) taken from the geological funds, and datasets from PANGAEA (www.pangaea.de). About 82 minerals and groups of minerals were included in the joint dataset. The density of the sample points varied significantly in all seas: 1394 data points in the Barents Sea, 713 in the Kara Sea, 487 in the Laptev Sea, 196 in the East Siberian Sea, and 245 in the Chukchi Sea. These data allowed comparing the areas in terms of major minerals and associations. Maps of prevailing and significant components were created in ODV (Schlitzer, 2020) to demonstrate the differences between the seas and indicate the sites of remarkable changes in the source rocks. Additionally, the standardized ratio was calculated to perform quantitative comparison: the sea average was divided by the weighted sea average and then the ratio of that number to the mineral average was found. Only the minerals present in at least four seas and amounting to at least 20 points per sea were considered. As a result, water areas with the highest content of particular minerals were detected. The ratio varied from 0 to 3,4. Combining the ratio data for various minerals allowed mapping specific groups or provinces for every sea and within the seas.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Kosheleva, V.A., &amp; Yashin, D.S. (1999). Bottom Sediments of the Arctic Seas. St. Petersburg: VNIIOkeangeologia, 286pp. (in Russian).&lt;/p&gt;&lt;p&gt;PANGAEA. Data Publisher for Earth &amp; Environmental Science https://www.pangaea.de/&lt;/p&gt;&lt;p&gt;Schlitzer, R. (2020). Ocean Data View, Retrieved from https://odv.awi.de.&lt;/p&gt;&lt;p&gt;Stein, R. (2008). Arctic Ocean Sediments: Processes, Proxies, and Paleoenvironment. Oxford: Elsevier, 602pp.&lt;/p&gt;&lt;p&gt;Vogt, C. (1997). Regional and temporal variations of mineral assemblages in Arctic Ocean sediments as a climatic indicator during glacial/interglacial changes. Berichte Zur Polarforschung, 251, 309pp.&lt;/p&gt;


Author(s):  
Takuji Waseda ◽  
Takehiko Nose ◽  
Adrean Webb

The long-term trends of the expected largest waves in the ice-free Arctic waters from Laptev to Beaufort Seas was studied analyzing the ERA-interim reanalysis from 1979 to 2016. The analysis showed that the positive trend is largest in October and increased almost 70 cm in 38 years. For ships navigating the Northern Ship Route, it is important to know what the possible largest waves to expect during its cruise. In view of conducting the extreme value analysis, the uncertainty of the largest wave needs to be validated. However, the observation in the Arctic Ocean is limited. We, therefore, rely on the reanalysis wave products in the Arctic Ocean, whose uncertainty is yet to be determined. ERA-Interim and ERA-5 are compared in the Laptev, the East Siberian, Chukchi and Beaufort Seas. The comparison is relevant as the two products differ in its horizontal grid resolution and availability of the satellite altimeter significant wave height data assimilation. During 2010–2016 when the ERA5 is available, only a small difference from ERA-Interim was detected in the mean. However, the expected largest waves in the domain tended to be large for the ERA-5, 8% normalized bias. The tendency was quite similar with a high correlation of 0.98.


2018 ◽  
Vol 9 (1) ◽  
pp. 283-311
Author(s):  
Clive R. Symmons

It is generally accepted that UNCLOS applies to polar seas. However, particular problems can arise thereunder in such seas because of their ice-bound environment. One such regional problem is because global warming causes particular issues for insular formations there; not only in terms of the very definition of ‘islands’ (e.g., is frozen sea water equivalent to “land” in terms of above-surface appearance under Art. 121 [1] of UNCLOS?); but also in terms of their lawful use in generation of maritime zones therefrom. For example, in recent years new above-surface formations have been discovered in the Arctic (such as ‘Yaya Island’) because of glacial melting and sudden visibility. These formations may potentially generate new maritime zones for their owner State (albeit not EEZs/continental shelves because of Art. 121 [3] of UNCLOS); and may be opportunistically used in negotiation of maritime polar boundaries (as in the case of Tobias Island off Greenland). Where tips of glacial capes have been used as straight baseline points, any remaining terrestrial formations may be a useful ‘fall-back’ position on ice melt-down. Typically low-lying new terrestrial features (now uncovered by glaciers) may have no prospect of long-term existence above sea level; and some may have inherent mobility (as is a particular Arctic problem with ‘barrier islands’). The other side of the coin of polar ice melt-down is that existing low-lying and small islands will likely disappear with increasing sea levels; so causing problems of continued use as basepoints for generation of maritime zones; and a potential duty to retract maritime claims.


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