The Air-Sea Nitrous Oxide Flux along Cruise Tracks to the Arctic Ocean and Southern Ocean

Samples of seawater from the North American Arctic show that the region is neither a major source nor sink of methane and nitrous oxide to the overlying atmosphere.

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32 Polar Oceans and Law of the Sea

10.1093/law/9780198715481.003.0032 ◽

2015 ◽

Author(s):

Scott Karen N ◽

VanderZwaag David L

Keyword(s):

Southern Ocean ◽

Arctic Ocean ◽

The Arctic ◽

Law Of The Sea ◽

Marine Resources ◽

General Law ◽

Ocean Governance ◽

The Arctic Ocean ◽

Future Challenges ◽

The Antarctic

This chapter assesses the implementation of the law of the sea in the Arctic Ocean and Southern Ocean, focusing on the issues of disputed sovereignty, environmental vulnerabilities, and access to marine resources. It highlights how the two regions are ‘poles together’, sharing some key governance similarities, such as being subject to general law of the sea provisions applicable to maritime safety and environmental protection. It describes how the regions are ‘poles apart’ by examining the differing law of the sea contexts and divergent regional approaches and challenges to ocean governance in the Arctic and Antarctic, respectively. It identifies future challenges for both regions focusing on institutional developments in the Arctic and the development of new spatially-focused conservation tools in the Antarctic.

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Nitrous oxide and methane in a changing Arctic Ocean

AMBIO ◽

10.1007/s13280-021-01633-8 ◽

2021 ◽

Author(s):

Andrew P. Rees ◽

Hermann W. Bange ◽

Damian L. Arévalo-Martínez ◽

Yuri Artioli ◽

Dawn M. Ashby ◽

...

Keyword(s):

Nitrous Oxide ◽

Arctic Ocean ◽

Environmental Changes ◽

Trace Gases ◽

Gas Production ◽

The Arctic ◽

The Arctic Ocean ◽

Ice Retreat ◽

Arctic Atmosphere ◽

Physical And Chemical

AbstractHuman activities are changing the Arctic environment at an unprecedented rate resulting in rapid warming, freshening, sea ice retreat and ocean acidification of the Arctic Ocean. Trace gases such as nitrous oxide (N2O) and methane (CH4) play important roles in both the atmospheric reactivity and radiative budget of the Arctic and thus have a high potential to influence the region’s climate. However, little is known about how these rapid physical and chemical changes will impact the emissions of major climate-relevant trace gases from the Arctic Ocean. The combined consequences of these stressors present a complex combination of environmental changes which might impact on trace gas production and their subsequent release to the Arctic atmosphere. Here we present our current understanding of nitrous oxide and methane cycling in the Arctic Ocean and its relevance for regional and global atmosphere and climate and offer our thoughts on how this might change over coming decades.

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The Influence of Sea Ice on Ocean Heat Uptake in Response to Increasing CO2

Journal of Climate ◽

10.1175/jcli3756.1 ◽

2006 ◽

Vol 19 (11) ◽

pp. 2437-2450 ◽

Cited By ~ 94

Author(s):

C. M. Bitz ◽

P. R. Gent ◽

R. A. Woodgate ◽

M. M. Holland ◽

R. Lindsay

Keyword(s):

Southern Ocean ◽

Sea Ice ◽

Arctic Ocean ◽

North Atlantic ◽

Deep Ocean ◽

Temperature Gradients ◽

The Arctic ◽

Ocean Heat Uptake ◽

Heat Uptake ◽

The Arctic Ocean

Abstract Two significant changes in ocean heat uptake that occur in the vicinity of sea ice cover in response to increasing CO2 are investigated with Community Climate System Model version 3 (CCSM3): a deep warming below ∼500 m and extending down several kilometers in the Southern Ocean and warming in a ∼200-m layer just below the surface in the Arctic Ocean. Ocean heat uptake caused by sea ice retreat is isolated by running the model with the sea ice albedo reduced artificially alone. This integration has a climate response with strong ocean heat uptake in the Southern Ocean and modest ocean heat uptake in the subsurface Arctic Ocean. The Arctic Ocean warming results from enhanced ocean heat transport from the northern North Atlantic. At the time of CO2 doubling, about 1/3 of the heat transport anomaly results from advection of anomalously warm water and 2/3 results from strengthened inflow. At the same time the overturning circulation is strengthened in the northern North Atlantic and Arctic Oceans. Wind stress changes cannot explain the circulation changes, which instead appear related to strengthened convection along the Siberian shelves. Deep ocean warming in the Southern Ocean is initiated by weakened convection, which is mainly a result of surface freshening through altered sea ice and ocean freshwater transport. Below about 500 m, changes in convection reduce the vertical and meridional temperature gradients in the Southern Ocean, which significantly reduce isopycnal diffusion of heat upward around Antarctica. The geometry of the sea ice cover and its influence on convection have a strong influence on ocean temperature gradients, making sea ice an important player in deep ocean heat uptake in the Southern Ocean.

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Seasonal nitrogen fluxes of the Lena River Delta

AMBIO ◽

10.1007/s13280-021-01665-0 ◽

2021 ◽

Author(s):

Tina Sanders ◽

Claudia Fiencke ◽

Matthias Fuchs ◽

Charlotte Haugk ◽

Bennet Juhls ◽

...

Keyword(s):

Nitrous Oxide ◽

Arctic Ocean ◽

Organic Nitrogen ◽

Inorganic Nitrogen ◽

The Arctic ◽

Nitrous Oxide Emissions ◽

Sampling Station ◽

Lena River ◽

The Arctic Ocean ◽

One Year

AbstractThe Arctic is nutrient limited, particularly by nitrogen, and is impacted by anthropogenic global warming which occurs approximately twice as fast compared to the global average. Arctic warming intensifies thawing of permafrost-affected soils releasing their large organic nitrogen reservoir. This organic nitrogen reaches hydrological systems, is remineralized to reactive inorganic nitrogen, and is transported to the Arctic Ocean via large rivers. We estimate the load of nitrogen supplied from terrestrial sources into the Arctic Ocean by sampling in the Lena River and its Delta. We took water samples along one of the major deltaic channels in winter and summer in 2019 and sampling station in the central delta over a one-year cycle. Additionally, we investigate the potential release of reactive nitrogen, including nitrous oxide from soils in the Delta. We found that the Lena transported nitrogen as dissolved organic nitrogen to the coastal Arctic Ocean and that eroded soils are sources of reactive inorganic nitrogen such as ammonium and nitrate. The Lena and the Deltaic region apparently are considerable sources of nitrogen to nearshore coastal zone. The potential higher availability of inorganic nitrogen might be a source to enhance nitrous oxide emissions from terrestrial and aquatic sources to the atmosphere.

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