Their results, which are published this month in the Journal of Geophysical Research, show that there is a mismatch between what goes into the Arctic Ocean and what comes out.
This is the first study to look at the transport of dissolved inorganic nutrients nitrate, phosphate and silicate together, all of which are essential for life in the ocean. The study combined measurements of nutrient concentrations with measurements of how much water was transported across the main Arctic gateways – Davis Strait, Fram Strait, the Barents Sea Opening and Bering Strait – in summer 2005.
Growth of the tiny plants at the base of marine food chains, microalgae, in the Arctic Ocean is fuelled by nutrient inputs from the Pacific and Atlantic Oceans, and from rivers around the Arctic Ocean rim. These riverine inputs are increasing as a result of increasing temperatures, because nutrients previously locked up in frozen soils – or 'permafrost' – are being released as the permafrost thaws.
While scientists are trying to understand how this increase in nutrients is influencing the growth of Arctic microalgae, the final fate of the nutrients is also of interest because they may support marine ecosystems elsewhere, carried there by ocean currents.
In the study, the researchers looked at all oceanic inputs and outputs of the three nutrients. They found that the nitrate coming into the Arctic Ocean balanced how much goes out. But for silicate and phosphate, more goes out into the North Atlantic than comes into the Arctic Ocean.
"These findings have important implications," says Dr Sinhué Torres-Valdés of the National Oceanography Centre, lead author of the paper.
"Firstly, the imbalances indicate that the Arctic Ocean is an important source of phosphate and silicate to the North Atlantic. Secondly, while nitrate transports are balanced, in the Arctic large amounts of nitrogen are lost to the atmosphere as nitrogen gas through a process called denitrification."
So where do the extra nutrients come from?
"Data suggest that rivers can provide most of the silicate that is transported to the North Atlantic, which implies that further alterations on Arctic river nutrient loads will have a direct impact on nutrient transports to the Atlantic.
"In the case of nitrate and phosphate, no obvious sources seem to provide enough to offset the imbalance. We are therefore investigating the possibility that the extra nitrate and phosphate comes from dissolved organic matter – the decaying remains of microorganisms in the ocean and decaying remains from soils in river loads.
"We suggest that this work can serve as a baseline for monitoring how nutrient availability varies as the Arctic continues to respond to the changing climate," says Dr Torres-Valdés.
The study, funded by the Natural Environment Research Council as part of the International Polar Year project 'Arctic Synoptic Basin-wide Oceanography', was a collaboration between the National Oceanography Centre, University of Southampton Ocean and Earth Science, Institute of Ocean Sciences Canada, Bedford Institute of Oceanography, Alfred Wegener Institute for Polar and Marine Research, and University of Alaska Fairbanks.
The paper 'Export of nutrients from the Arctic Ocean' was featured in Research Spotlight of EOS Transactions, American Geophysical Union.
Notes for editors
1. Reference: Torres-Valdés, S., T. Tsubouchi, S. Bacon, A. C. Naveira-Garabato, R. Sanders, F. A. McLaughlin, B. Petrie, G. Kattner, K. Azetsu-Scott, and T. E. Whitledge (2013), Export of nutrients from the Arctic Ocean, J. Geophys. Res.: Oceans, 118, doi:10.1002/jgrc.20063
2. Research Spotlight, EOS Transactions, American Geophysical Union highlights exciting new research from AGU journals. The paper was featured in Volume 94, Number 13, 26 March 2013.
3. The photo was taken during one of the expeditions to the Arctic aboard the Russian icebreaker Kapitan Dranitsyn in 2008 as part of the International Polar Year NERC-funded project Arctic Synoptic Basin-wide Oceanography (ASBO). The image shows the back of the icebreaker, which was carving out a circular opening in the ice at a sampling station. Credit Sinhué Torres-Valdés.
4. The National Oceanography Centre (NOC) is the UK's leading institution for integrated coastal and deep ocean research. NOC operates the Royal Research Ships James Cook and Discovery and develops technology for coastal and deep ocean research. Working with its partners NOC provides long-term marine science capability including: sustained ocean observing, mapping and surveying, data management and scientific advice.
5. NOC operates at two sites, Southampton and Liverpool, with the headquarters based in Southampton.
6. Among the resources that NOC provides on behalf of the UK are the British Oceanographic Data Centre (BODC), the Marine Autonomous and Robotic Systems (MARS) facility, the National Tide and Sea Level Facility (NTSLF), the Permanent Service for Mean Sea Level (PSMSL) and British Ocean Sediment Core Research Facility (BOSCORF).
7. The National Oceanography Centre is wholly owned by the Natural Environment Research Council (NERC).
Catherine Beswick, National Oceanography Centre
Catherine Beswick | EurekAlert!
Further reports about: > American Geophysical Union > Arctic Ocean > Atlantic mollies > EOS > Environment > Environment Research > Facility Management > Marine science > Natural Environment Research > Oceanography > Pacific Ocean > Polar Day > Synoptic > deep ocean > food chain > marine ecosystem > sea snails
New study: How does Europe become a leading player for software and IT services?
03.04.2017 | Fraunhofer-Institut für System- und Innovationsforschung (ISI)
Reusable carbon nanotubes could be the water filter of the future, says RIT study
30.03.2017 | Rochester Institute of Technology
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
25.04.2017 | Physics and Astronomy
25.04.2017 | Materials Sciences
25.04.2017 | Life Sciences