scholarly journals Changes in Diversity and Species Composition Across Multiple Assemblages in the eastern Chukchi Sea During Two Contrasting Years are Consistent with Borealization

Oceanography ◽  
2021 ◽  
Vol 34 (2) ◽  
Author(s):  
Franz Mueter ◽  
◽  
Katrin Iken ◽  
Lee Cooper ◽  
Jacqueline Grebmeier ◽  
...  
Keyword(s):  
Species Composition ◽  
Chukchi Sea ◽  
Benthic Communities ◽  
Taxonomic Diversity ◽  
Demersal Fish ◽  
Taxonomic Composition ◽  
The Arctic ◽  
Global Ocean ◽  
Marine Biodiversity ◽  
Study Region

The Arctic Marine Biodiversity Observing Network monitors biological assemblages on taxonomic scales ranging from microbes to seabirds on the northeast Chukchi Sea shelf to improve understanding of their responses to changing environmental conditions, including climate change. Here, we compare two years, 2015 and 2017, the latter characterized by a much larger spatial extent of warmer, more saline Pacific waters within the study region. These environmental differences were associated with changes in the taxonomic diversity and species composition of eight different assemblages. Impacts included decreases in the diversity and abundance of benthic species and increases in the diversity and abundance of zooplankton and demersal fish. These observations are consistent with the expected patterns of borealization, a term that describes changes from polar to more southern or boreal conditions and that have been observed on other Arctic inflow shelves where there is communication with the global ocean. A decoupling of the seabird assemblage from other assemblages in 2017 suggests that seabirds were unable to fully adjust to changing prey conditions in 2017. Pronounced differences in the taxonomic composition and a substantial decline in taxonomic diversity of bacteria and protists in 2017 remain unexplained but suggest that these microbes are highly susceptible to changing conditions. Continued warming of the Chukchi Sea will likely result in further borealization, with differential impacts on pelagic and benthic communities.

scholarly journals Seasonal variability of meiobenthic assemblages inhabiting the Nottinghambukta tidal flat, SW Spitsbergen

2019 ◽  
Vol 19 (4) ◽  
pp. 175-189
Author(s):  
Barbara Wojtasik ◽  
Kamil Nowiński ◽  
Wioletta Staniszewska ◽  
Anna Kheireddine
Keyword(s):  
Species Composition ◽  
Qualitative Analysis ◽  
Tidal Flat ◽  
Seasonal Variability ◽  
Taxonomic Diversity ◽  
Summer Season ◽  
The Arctic ◽  
Considerable Decrease ◽  
Hydrological Characteristics ◽  
Land Runoff

AbstractThe aim of the work was to describe the variability of a group of meiobenthos inhabiting a tidal flat in Nottinghambukta which is influenced by the diverse conditions of a seasonal as well as multi-annual cyclicity. Samples were collected in five series, i.e. during the Arctic spring (2001), summer (2000 and 2001) and autumn (2001). The material for qualitative analysis was collected from sites with different hydrological characteristics. The following major meiobenthic taxa were found: Metazoa, i.e. Nematoda and Crustacea (Ostracoda and Copepoda-Harpacticoida), and Foraminifera. Unstable conditions in the bay result in a seasonal variability in the species composition as well as an uneven colonisation of the Nottinghambukta area by meiobenthos. The lowest taxonomic diversity occurs in summer, but it increases in autumn when the land runoff ceases. Based on the conducted analysis, it can be concluded that the inflow of seawater in autumn brings on the occurrence of new taxa, which probably inhabit the bay temporarily until the summer season during which the highly variable conditions cause a change in the species composition. For the series of samples collected in July 2000 and 2001, the species composition for Harpacticoida was determined. The taxonomic diversity of the harpacticoid assemblage inhabiting the bay was observed in the two subsequent years. Moreover, during the study duration a considerable decrease was observed in the abundance of Ostracoda in Nottinghambukta.

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>

scholarly journals Benthos Expert Network: Findings and recommendations from the Circumpolar Biodiversity Monitoring Program’s State of the Arctic Marine Biodiversity Report (SAMBR)

2018 ◽  
Author(s):  
Virginie Roy ◽  
Lis Lindal Jørgensen ◽  
Philippe Archambault ◽  
Martin Blicher ◽  
Nina Denisenko ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Benthic Communities ◽  
Monitoring Program ◽  
The Arctic ◽  
Marine Biodiversity ◽  
Biodiversity Monitoring ◽  
Arctic Seas ◽  
Marine Areas ◽  
Expert Network

Currently, > 4,000 macro- and megabenthic invertebrate species are known from Arctic seas, representing the majority of marine faunal diversity in this region. This estimate is expected to increase with future studies. Benthic invertebrates are important ecosystem components as food for fishes, marine mammals, seabirds and humans. The Benthos Expert Network of the Circumpolar Biodiversity Monitoring Program (CBMP) aggregated and reviewed information on the population status and trends of macro- and megabenthic invertebrates across eight Arctic Marine Areas as well as the state of current monitoring efforts for these communities. Drivers are affecting benthic communities on a variety of scales, ranging from pan-Arctic (related to climate change, such as warming, ice decline and acidification) to regional or local scales (such as trawling, river/glacier discharge, and invasive species). Long-term benthic monitoring efforts have largely focused on macro- and megabenthic communities of the Chukchi and Barents Seas. Recently, they are increasing in waters off Greenland and Iceland, as well as in the Canadian Arctic and the Norwegian Sea. All other Arctic Marine Areas are lacking long-term monitoring. The presentation will summarize current level of knowledge and monitoring across the Arctic, drivers of observed trends, and knowledge and monitoring gaps.

scholarly journals Family Cruciferae Juss. (Brassicaceae Burnett) of SAKHA (Yakutia) Republic

VAVILOVIA ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 3-34
Author(s):  
V. I. Dorofeyev
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Geographical Distribution ◽  
Endemic Species ◽  
Taxonomic Composition ◽  
The Arctic ◽  
New Combinations ◽  
Total Species Richness ◽  
Total Species ◽  
Cruciferae Family

The paper offers a new revision of the species composition of the Cruciferae family in Yakutia, which is supplemented by information on the geographical distribution and taxonomic composition. In the present work, the crucifers of Yakutia are represented by 39 genera and 102 species. Among them, there are two endemic species (Boechera falcata (Turcz.) Al-Shehbaz and Smelowskia jacutica (Botsch. et Karav.) Al-Shehbaz et Warwick), and one subendemic (Isatis jacutensis (N. Busch) N. Busch). Traditionally, the genus Draba is the richest in the number of species in the territories reaching into the Arctic. At present, taking the latest processing of the genus by V. V. Petrovsky (Petrovsky, 2018) into account, it numbers 32 species, which amounts to about 1/3 of the total species richness of this family in Yakutia. The paper summarizes the nomenclature changes that have affected a number of representatives of this family in recent years, and proposes new combinations in the genus Boechera (B. pendula (L.) V. I. Dorof. Comb. Nov.) and Thellungiella (T. bursifolia (DC.) V. I. Dorof. Comb. Nov.). An analysis of the diversity of crucifers made it possible to assert that the flora of Yakutia is obviously insufficiently studied in its northwest and northeast reaches, and to suggest that the floristic zoning of Yakutia should be supplemented by outlining three supra-regions, namely the Verkhoyansk (eastern), Vilui (western) and Arctic (northern) supra-regions.

scholarly journals Benthos Expert Network: Findings and recommendations from the Circumpolar Biodiversity Monitoring Program’s State of the Arctic Marine Biodiversity Report (SAMBR)

2018 ◽  
Author(s):  
Virginie Roy ◽  
Lis Lindal Jørgensen ◽  
Philippe Archambault ◽  
Martin Blicher ◽  
Nina Denisenko ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Benthic Communities ◽  
Monitoring Program ◽  
The Arctic ◽  
Marine Biodiversity ◽  
Biodiversity Monitoring ◽  
Arctic Seas ◽  
Marine Areas ◽  
Expert Network

Currently, > 4,000 macro- and megabenthic invertebrate species are known from Arctic seas, representing the majority of marine faunal diversity in this region. This estimate is expected to increase with future studies. Benthic invertebrates are important ecosystem components as food for fishes, marine mammals, seabirds and humans. The Benthos Expert Network of the Circumpolar Biodiversity Monitoring Program (CBMP) aggregated and reviewed information on the population status and trends of macro- and megabenthic invertebrates across eight Arctic Marine Areas as well as the state of current monitoring efforts for these communities. Drivers are affecting benthic communities on a variety of scales, ranging from pan-Arctic (related to climate change, such as warming, ice decline and acidification) to regional or local scales (such as trawling, river/glacier discharge, and invasive species). Long-term benthic monitoring efforts have largely focused on macro- and megabenthic communities of the Chukchi and Barents Seas. Recently, they are increasing in waters off Greenland and Iceland, as well as in the Canadian Arctic and the Norwegian Sea. All other Arctic Marine Areas are lacking long-term monitoring. The presentation will summarize current level of knowledge and monitoring across the Arctic, drivers of observed trends, and knowledge and monitoring gaps.

scholarly journals SEASONAL CONDITIONS OF PHYTO-FOULING OF A COASTAL PROTECTION HYDROTECHNICAL STRUCTURE (KRUGLAYA BAY, BLACK SEA)

Ekosistemy ◽  
2021 ◽  
pp. 49-59
Author(s):  
I. K. Evstigneeva ◽  
I. N. Tankovskaya
Keyword(s):  
Species Composition ◽  
Taxonomic Diversity ◽  
Taxonomic Composition ◽  
Coastal Protection ◽  
Taxonomic Structure ◽  
Ecological Groups ◽  
Seasonal Fluctuations ◽  
Quantitative Characteristics ◽  
Hydrotechnical Structure ◽  
Occurrence Of Species

The species composition, ecological and taxonomic structure, quantitative characteristics and variability of phyto-fouling of the coastal hydrotechnical structure (Kruglaya Bay, Sevastopol) in spring, summer and autumn were studied. The taxonomic composition of fouling is represented by 45 species of 29 genera, 19 families, 12 orders, 4 classes of the divisions Chlorophyta, Ochrophyta and Rhodophyta. The taxonomic leaders of the community are Rhodophyta, Cladophorales, Ceramiales, Ulvaceae, Cladophoraceae, Ceramiaceae, Ulva, Cladophora, Ceramium, ecological — marine, leading, annual and oligosaprobic species. The fouling is dominated by species with a high and medium frequency of occurrence. Most of the proportions of taxa and ecological groups are most resistant. The taxonomic diversity of the entire phyto-growth, its Rhodophyta, constant flora nucleus, minor species and some ecogroups, the occurrence of species, phytomass, the degree of community discreteness and the qualitative composition of its production dominants and subdominants are subject to seasonal fluctuations. Each season, the variability of the species composition corresponds to the norm for biological objects, the degree of variability of the phytomass is higher.

scholarly journals CAS FGOALS-f3-L Large-ensemble Simulations for the CMIP6 Polar Amplification Model Intercomparison Project

2021 ◽  
Author(s):  
Bian He ◽  
Xiaoqi Zhang ◽  
Anmin Duan ◽  
Qing Bao ◽  
Yimin Liu ◽  
...  
Keyword(s):  
Time Lag ◽  
The Arctic ◽  
Global Ocean ◽  
Arctic Amplification ◽  
Model Intercomparison ◽  
Large Ensemble ◽  
Sea Ice Concentration ◽  
Ensemble Simulations ◽  
Polar Amplification ◽  
Intercomparison Project

AbstractLarge-ensemble simulations of the atmosphere-only time-slice experiments for the Polar Amplification Model Intercomparison Project (PAMIP) were carried out by the model group of the Chinese Academy of Sciences (CAS) Flexible Global Ocean-Atmosphere-Land System (FGOALS-f3-L). Eight groups of experiments forced by different combinations of the sea surface temperature (SST) and sea ice concentration (SIC) for pre-industrial, present-day, and future conditions were performed and published. The time-lag method was used to generate the 100 ensemble members, with each member integrating from 1 April 2000 to 30 June 2001 and the first two months as the spin-up period. The basic model responses of the surface air temperature (SAT) and precipitation were documented. The results indicate that Arctic amplification is mainly caused by Arctic SIC forcing changes. The SAT responses to the Arctic SIC decrease alone show an obvious increase over high latitudes, which is similar to the results from the combined forcing of SST and SIC. However, the change in global precipitation is dominated by the changes in the global SST rather than SIC, partly because tropical precipitation is mainly driven by local SST changes. The uncertainty of the model responses was also investigated through the analysis of the large-ensemble members. The relative roles of SST and SIC, together with their combined influence on Arctic amplification, are also discussed. All of these model datasets will contribute to PAMIP multi-model analysis and improve the understanding of polar amplification.

scholarly journals Air-Sea Interactions over Eddies in the Brazil-Malvinas Confluence

2021 ◽  
Vol 13 (7) ◽  
pp. 1335
Author(s):  
Ronald Souza ◽  
Luciano Pezzi ◽  
Sebastiaan Swart ◽  
Fabrício Oliveira ◽  
Marcelo Santini
Keyword(s):  
Latent Heat ◽  
Large Scale ◽  
Surface Wind ◽  
Heat Fluxes ◽  
Lower Atmosphere ◽  
Meteorological Variables ◽  
Global Ocean ◽  
Study Region ◽  
Cold Core

The Brazil–Malvinas Confluence (BMC) is one of the most dynamical regions of the global ocean. Its variability is dominated by the mesoscale, mainly expressed by the presence of meanders and eddies, which are understood to be local regulators of air-sea interaction processes. The objective of this work is to study the local modulation of air-sea interaction variables by the presence of either a warm (ED1) and a cold core (ED2) eddy, present in the BMC, during September to November 2013. The translation and lifespans of both eddies were determined using satellite-derived sea level anomaly (SLA) data. Time series of satellite-derived surface wind data, as well as these and other meteorological variables, retrieved from ERA5 reanalysis at the eddies’ successive positions in time, allowed us to investigate the temporal modulation of the lower atmosphere by the eddies’ presence along their translation and lifespan. The reanalysis data indicate a mean increase of 78% in sensible and 55% in latent heat fluxes along the warm eddy trajectory in comparison to the surrounding ocean of the study region. Over the cold core eddy, on the other hand, we noticed a mean reduction of 49% and 25% in sensible and latent heat fluxes, respectively, compared to the adjacent ocean. Additionally, a field campaign observed both eddies and the lower atmosphere from ship-borne observations before, during and after crossing both eddies in the study region during October 2013. The presence of the eddies was imprinted on several surface meteorological variables depending on the sea surface temperature (SST) in the eddy cores. In situ oceanographic and meteorological data, together with high frequency micrometeorological data, were also used here to demonstrate that the local, rather than the large scale forcing of the eddies on the atmosphere above, is, as expected, the principal driver of air-sea interaction when transient atmospheric systems are stable (not actively varying) in the study region. We also make use of the in situ data to show the differences (biases) between bulk heat flux estimates (used on atmospheric reanalysis products) and eddy covariance measurements (taken as “sea truth”) of both sensible and latent heat fluxes. The findings demonstrate the importance of short-term changes (minutes to hours) in both the atmosphere and the ocean in contributing to these biases. We conclude by emphasizing the importance of the mesoscale oceanographic structures in the BMC on impacting local air-sea heat fluxes and the marine atmospheric boundary layer stability, especially under large scale, high-pressure atmospheric conditions.

scholarly journals N2O dynamics in the western Arctic Ocean during the summer of 2017

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jang-Mu Heo ◽  
Seong-Su Kim ◽  
Sung-Ho Kang ◽  
Eun Jin Yang ◽  
Ki-Tae Park ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Environmental Changes ◽  
Chukchi Sea ◽  
Hot Spot ◽  
Open Water ◽  
Northern Region ◽  
The Arctic ◽  
Western Arctic Ocean ◽  
Deep Layers ◽  
Western Arctic

AbstractThe western Arctic Ocean (WAO) has experienced increased heat transport into the region, sea-ice reduction, and changes to the WAO nitrous oxide (N2O) cycles from greenhouse gases. We investigated WAO N2O dynamics through an intensive and precise N2O survey during the open-water season of summer 2017. The effects of physical processes (i.e., solubility and advection) were dominant in both the surface (0–50 m) and deep layers (200–2200 m) of the northern Chukchi Sea with an under-saturation of N2O. By contrast, both the surface layer (0–50 m) of the southern Chukchi Sea and the intermediate (50–200 m) layer of the northern Chukchi Sea were significantly influenced by biogeochemically derived N2O production (i.e., through nitrification), with N2O over-saturation. During summer 2017, the southern region acted as a source of atmospheric N2O (mean: + 2.3 ± 2.7 μmol N2O m−2 day−1), whereas the northern region acted as a sink (mean − 1.3 ± 1.5 μmol N2O m−2 day−1). If Arctic environmental changes continue to accelerate and consequently drive the productivity of the Arctic Ocean, the WAO may become a N2O “hot spot”, and therefore, a key region requiring continued observations to both understand N2O dynamics and possibly predict their future changes.

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