Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. Earth Science News .




ICE WORLD
Pioneering study calculates Arctic Ocean nutrient budget
by Staff Writers
Southampton UK (SPX) Apr 12, 2013


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 Sinhue Torres-Valdes. Credit: Credit: Sinhue Torres-Valdes.

The first study of its kind to calculate the amount of nutrients entering and leaving the Arctic Ocean has been carried out by scientists based at the National Oceanography Centre, Southampton.

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 Sinhue Torres-Valdes 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-Valdes.

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. Reference: Torres-Valdes, 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

.


Related Links
National Oceanography Centre, Southampton (UK)
Beyond the Ice Age






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





ICE WORLD
Byrd Came Oh-So-Close, But Probably Didn't Reach North Pole
Columbus OH (SPX) Apr 09, 2013
When renowned explorer Richard E. Byrd returned from the first-ever flight to the North Pole in 1926, he sparked a controversy that remains today: Did he actually reach the pole? Studying supercomputer simulations of atmospheric conditions on the day of the flight and double-checking Byrd's navigation techniques, a researcher at The Ohio State University has determined that Byrd indeed nea ... read more


ICE WORLD
Fukushima plant springs another radioactive leak

Hong Kong ferry crash captains face manslaughter charges

Americans back preparation for extreme weather and sea-level rise

Sensory helmet could mean firefighters are not left in the dark

ICE WORLD
Florida Tech professors present 'dark side of dark lightning' at conference

PETRA Reveals Coexisting Structures in Glass

Northrop Grumman G/ATOR Radar System Completes Government Testing at Wallops Island

Accidental discovery may lead to improved polymers

ICE WORLD
Scientists use islands to gauge rainfall's effect on landscapes

Research Enables Fishermen to Harvest Lucrative Shellfish on Georges Bank

Extreme Algae Blooms: The New Normal?

Call issued for nationwide U.S. marine biodiversity monitoring network

ICE WORLD
New chart shows the entire topography of the Antarctic seafloor in detail

New Models Predict Dramatically Greener Arctic in the Coming Decades

Scientists predict arctic could be free of sea ice in summer by 2050

Pioneering study calculates Arctic Ocean nutrient budget

ICE WORLD
Limiting greenhouse gas emissions from land use in Europe

Urban Grass Might Be Greener, but That Doesn't Mean It's "Greener"

Residents in China ordered to cull birds: media

Cuba faces vast land losses as sea levels rise

ICE WORLD
36 killed in three weeks of flooding in Kenya: ministry

Iran ups aid effort after deadly quake near nuclear plant

UC San Diego team achieves petaflop-level earthquake simulations on GPU-powered supercomputers

NASA Flies Dragon Eye Unmanned Aircraft Into Volcanic Plume

ICE WORLD
Alleged drug lord seized, but Africa trade grows

Sudan defence minister sees 'end' to Darfur uprising

Obama takes first step to selling arms to Somalia

Jailed Sudan coup officers seek Bashir's amnesty

ICE WORLD
Google adds 'digital estate planning' to its services

Better Understanding of Human Brain Supports National Security

Rare primate's vocal lip-smacks share features of human speech

Women and men perform the same in math




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement