DOC storage in Arctic seas: The role of continental shelves

Author(s):  
John J. Walsh
2010 ◽  
Vol 7 (1) ◽  
pp. 177-205
Author(s):  
K. Fennel

Abstract. Continental shelves play a key role in the cycling of nitrogen and carbon. Here the physical transport and biogeochemical transformation processes affecting the fluxes into and out of continental shelf systems are reviewed, and their role in the global cycling of both elements is discussed. Uncertainties in observation-based estimates of nitrogen and carbon fluxes mostly result from uncertainties in the shelf-open ocean exchange of organic and inorganic matter, which is hard to quantify based on observations alone, but can be inferred from biogeochemical models. Model-based nitrogen and carbon budgets are presented for the Northwestern North Atlantic continental shelf. Results indicate that shelves are an important sink for fixed nitrogen and a source of alkalinity, but are not much more efficient in exporting organic carbon to the deep ocean than the adjacent open ocean for the shelf region considered.


Ocean Science ◽  
2010 ◽  
Vol 6 (2) ◽  
pp. 539-548 ◽  
Author(s):  
K. Fennel

Abstract. Continental shelves play a key role in the cycling of nitrogen and carbon. Here the physical transport and biogeochemical transformation processes affecting the fluxes into and out of continental shelf systems are reviewed, and their role in the global cycling of both elements is discussed. Uncertainties in the magnitude of organic and inorganic matter exchange between shelves and the open ocean is a major source of uncertainty in observation-based estimates of nitrogen and carbon fluxes. The shelf-open ocean exchange is hard to quantify based on observations alone, but can be inferred from biogeochemical models. Model-based nitrogen and carbon budgets are presented for the Northwestern North Atlantic continental shelf. Results indicate that shelves are an important sink for fixed nitrogen and a source of alkalinity, but are not much more efficient in exporting organic carbon to the deep ocean than the adjacent open ocean for the shelf region considered.


Polar Record ◽  
1975 ◽  
Vol 17 (111) ◽  
pp. 595-626 ◽  
Author(s):  
Mark A. Curtis

The study of marine life from the bottom of Arctic and sub-Arctic seas has long been a topic of scientific interest, and such work represents an important part of contemporary biological research in the polar regions. Contributions to this field have been made through the collective efforts of investigators from many nations over the years and include findings of considerable significance for life science studies as a whole, as well as for specific polar problems. Together with contemporary research on the pelagic and planktonic biota of northern waters, current work on the bottom fauna (benthos) offers much potential for developing our fundamental knowledge of biological processes in the Arctic seas.


1996 ◽  
Vol 351 (1343) ◽  
pp. 1105-1112 ◽  

In this volume we have considered the problems of investigation special to cephalopods. Almost all our knowledge of their general biology is restricted to the shelf-living, muscular, negatively buoyant (the Loliginidae and Octopodidae) or gas-supported species (the Sepiidae and Nautilidae) and members of the Ommastrephidae which move on to the continental shelves at certain seasons. These species of the continental shelves comprise only about 15% of all cephalopod genera and live in water of less than 300 m depth, which covers only 6% of the Earth’s surface. They do not represent the majority of cephalopod species or much of their total biomass; 85 % of genera are spread in the upper 2000 m and across the bottom of the deep oceans, which occupy 66 % of the Earth’s surface. Over 40% of these genera are neutrally buoyant by oil or chemical means and may have very different lifestyles from the forms we know from shallow water. Improvement of our knowledge of the ecology of deep water forms is hindered by our poor direct sampling methods and rests largely upon sampling from stomachs or regurgitations of the predators that eat cephalopods.


Terra Nova ◽  
1996 ◽  
Vol 8 (3) ◽  
pp. 213-222 ◽  
Author(s):  
H.-P. Plag ◽  
W.E.N. Austin ◽  
D.F. Belknap ◽  
R.J.N. Devoy ◽  
J. England ◽  
...  

2020 ◽  
Author(s):  
Berill Blair ◽  
Malte Muller ◽  
Cyril Palerme ◽  
Rayne Blair ◽  
David Crookall ◽  
...  

<p>A group of scientists in a multi-national consortium have worked together to improve climate services for maritime actors in Arctic waters. The consortium under the project Enhancing the Saliency of climate services for marine mobility Sectors in European Arctic Seas (SALIENSEAS) running 2017-2020, has aimed to coproduce improved (sub)seasonal sea ice forecast and iceberg detection services. The project involved metservice experts and end users to collaboratively explore ways in which forecast services can reduce uncertainties for stakeholders.</p><p>However, direct questioning about perceived risks and uncertainties during operations do not always lend themselves well to traditional inquiries such as self-report surveys. Stakeholders can and do experience difficulty accurately recalling and rating past perceptions and connecting them to varying environmental conditions. As an alternative, experiential approaches such as participatory simulation are able to furnish a reliable environment that facilitates replication, experimenting and learning.</p><p>We present a novel approach with which to explore effects from the reliability of sub-seasonal sea ice forecasts on the user’s perception of uncertainties. Our methods combine anticipatory methods through the use of scenarios with participatory simulation in a computerized simulation/game called ICEWISE. In our paper we will:</p><ul><li>introduce the game and the newly developed seasonal sea ice forecast</li> <li>present results from a gaming workshop conducted with experts in Arctic marine operations</li> <li>discuss the role of full and structured debriefing in maximizing the learning that takes place during gaming sessions</li> </ul><p>To conclude, we reflect on the upcoming stages of data collection, which will culminate in an exploratory model. The model will serve to inform sea ice service providers about the potential mediating effects deriving from the reliability of sea ice forecasts on the user’s own perceived confidence in successful voyage planning.   </p>


2014 ◽  
Vol 32 (3) ◽  
pp. 515
Author(s):  
Márcio Fabiano de Souza ◽  
Carlos Augusto França Schettini

ABSTRACT. The importance of understanding coastal processes and their relationships to continental shelves has become increasingly important as coastal areasexperience great socio-economic growth. In this context, Tijucas Bay and its interactions with the adjacent continental shelf was a subject of study through the use ofa numerical model (MOHID Water Modeling System) for analysis of its hydrodynamics, exchanges of water masses between the bay and the continental shelf and thewater’s residence time in the bay. Simulations were run for 30 or more days. Boundary conditions for the simulations were tides, constant river discharge (24 m3.s–1)and winds. Wind time series represented typical conditions in the region, with NE winds (3 m.s–1) forcing the domain for five days, then turning in the counterclockwisedirection for 12 hours until they were oriented in the SE direction (8 m.s–1), remaining two days in this direction and again turning counterclockwise for 12 hours andending in the NE direction. Three scenarios have been proposed for the experiment; scenario 1 was forced by tides and river discharge, and scenarios 2 and 3 wereforced by tides, river discharge and winds. The difference between scenarios 2 and 3 was the wind direction at the beginning of the simulations: scenario 2 began withNE winds, and scenario 3 began with SE winds. The results showed that the hydrodynamics and water exchange of Tijucas Bay were strongly influenced by tide andwind. The tide provided the input and output water pattern in the bay, while the wind accelerated the process, increasing the speed of exchange between the bay and theadjacent shelf. Superficial layers were the most affected by the winds. The easternmost portion of the bay exhibited the greatest current speeds, with a tendency to forma gyre current with water input at one end and output at the other, depending upon wind direction. In the shallower regions, currents exhibited their greatest speeds,while in the deeper areas, the inverse was found. The residence time for scenario 1 was 75 days, and for scenarios 2 and 3, the residence times were 19 and 15 days,respectively. The hydrodynamics of Tijucas Bay is a sum of processes related to its forcings; however, it is important to highlight the role of winds as one of the majordeterminants of the dynamics of this region, directly affecting transport throughout the bay.Keywords: circulation, estuary-shelf interaction, residence time. RESUMO. Atualmente o entendimento de processos costeiros e sua relação com a plataforma continental ganha importância a medida em que as regiões costeira tornam-se áreas de grande expansão sócio-econômica. Neste contexto, a Baía de Tijucas e sua interação com a plataforma adjacente foi alvo de investigação através do uso de modelo numérico (MOHID) para análise da hidrodinâmica, troca de massas de água entre baía e plataforma e tempo de residência da baía. As simulações correram por 30 dias ou mais. As condições de fronteiras para as simulações foram maré, descarga fluvial constante (24 m3.s–1) e ventos. As séries temporais deventos representam condições típicas da região com ventos NE (3 m.s–1) forçando o domínio por 5 dias girando no sentido anti-horário durante 12 horas até a direção SE (8 m.s–1), permanecendo por 2 dias nesta direção e novamente girando no sentido anti-horário por 12 horas até a direção NE. Três cenários foram propostos parao experimento, cenário 1 foi forçado por marés e descarga fluvial, cen´arios 2 e 3 forçados por marés, descarga fluvial e ventos. A diferenc¸a entre os cenários 2 e 3 é a direçãoo do vento no início das simulações, cenário 2 começa com vento NE e cenário 3 com vento SE. Os resultados mostram que a hidrodinâmica e a troca de água da Baía de Tijucas são fortemente influenciadas pela maré e pelo vento. A maré proporciona um padrão de entrada e saída de água da baía, enquanto o vento acelera oprocesso aumentando as velocidades de troca entre baía e plataforma adjacente. As camadas superficiais são mais afetadas pelos ventos. As extremidades da baía nasua porção mais a leste apresentam as maiores velocidades das correntes, a tendência é a formação de uma corrente em forma de giro com entrada de água por uma extremidade e saída por outra, dependendo da direção do vento. Nas partes mais rasas as correntes apresentam maiores velocidades enquanto nas partes mais profundas é o inverso. O tempo de residência para o cenário 1 foi de 75 dias, enquanto os cenários 2 e 3 apresentaram tempo de residência de 19 e 15 dias, respectivamente.A hidrodinâmica da Baía de Tijucas é um somatório de processos relacionados às suas forçantes. Entretanto ´e importante destacar o papel dos ventos como um dosprincipais condicionantes da dinâmica desta região afetando diretamente o transporte baía afora.Palavras-chave: circulação, interação estuário-plataforma, tempo de residência.


Author(s):  
Subedi Surya P

This chapter discusses the role of the Commission on the Limits of the Continental Shelf, established under the United Nations Convention on the Law of the Sea (UNCLOS), in the governance of the seas and oceans. It first considers the competition for the resources of the seas and oceans among States before providing an overview of the functions of the Commission. It then outlines the criteria for the establishment of the outer limits of the continental shelf and proceeds by analysing the challenges for the Commission in dealing with claims by coastal States for the extension of their continental shelves beyond 200 nautical miles. It also examines issues such as ambiguity in the law itself, the workload of the Commission, problems of enforcement, questions of transparency and accountability, financial resources, and independence of the Commissioners.


2021 ◽  
pp. 306-316
Author(s):  
Е.N. Bubnova ◽  
◽  
S.А. Bondarenko ◽  
M.L. Georgievа ◽  
◽  
...  

The role of marine mycobiota, which includes marine fungi and fungi-like, is, first of all, in the decomposition of detritus, as well as in the formation of symbiotic relationships with other hydrobionts, and most often it is parasitism or mutualism. The paper presents a generalization of data on the mycobiota of the Barents Sea, as the most studied of the Arctic seas. This allowed the authors to evaluate the role of this little-studied component of the ecosystem, as well as to determine future directions of research of marine mycobiota for the Arctic region as a whole.


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