Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



WATER WORLD
Marine carbon sinking rates confirm importance of polar oceans
by Staff Writers
Seattle WA (SPX) Jul 27, 2016


Results show that the transfer efficiency of organic carbon from the surface to the deep ocean ranges from just 5 percent in the subtropics to around 25 percent near the poles. Image courtesy Thomas Weber/University of Washington. For a larger version of this image please go here.

About the same amount of atmospheric carbon that goes into creating plants on land goes into the bodies of tiny marine plants known as plankton. When these plants die and sink, bacteria feed on their sinking corpses and return their carbon to the seawater. When plankton sink deep enough before being eaten, this carbon is taken out of circulation as a greenhouse gas to remain trapped in the deep ocean for centuries.

How much of this happens in different regions of the ocean would seem like an academic question, except during an era when humanity is spewing carbon dioxide into the air at record-high levels and wondering where all that carbon will go in the future.

A University of Washington study published this week (July 25) in the Proceedings of the National Academy of Sciences uses a new approach to get a global picture of the fate of marine carbon. It finds that the polar seas export organic carbon to the deep sea, where it can no longer trap heat from the sun, about five times as efficiently as in other parts of the ocean.

"The high latitudes are much more efficient at transferring carbon into the deep ocean," said first author Thomas Weber, who did the work as a postdoctoral researcher at the UW and is now an assistant professor at the University of Rochester in New York. "Understanding how this happens will certainly allow a more complete prediction of ocean responses to climate change."

The planet has many carbon sinks, or routes that transfer heat-trapping carbon from the atmosphere into other parts of the Earth system. This sink is a literal one. Carbon-rich plankton detritus clumps together to form marine snow that drifts down through the water and provides food for deeper-dwelling organisms. The continual supply of organic carbon in particles from the surface to the deep sea is known as the "biological pump."

This pump had been thought to operate at similar strength throughout the oceans, but the new study finds a strong regional pattern. The authors find that about 25 percent of organic particles sinking from the surface in the polar oceans reach at least 1 kilometer (0.6 miles) - the depth required for long-term storage in deep waters or the seafloor.

Just 5 percent of sinking carbon in the subtropics makes it that far, while the rest is released into shallower water where it can soon rejoin the atmosphere. The tropics have an intermediate value of about 15 percent.

"This highlights the importance of the polar ocean - the cold, high-latitude parts of the ocean - for their ability to store carbon over long time periods," said co-author Curtis Deutsch, a UW associate professor of oceanography.

The growth of marine plants at the ocean's sunlit surface is well-studied, but what happens a mile down is more mysterious. For many years, scientists have put floating sediment traps at different depths to try to learn how deep the particles reach, but the results have been inconclusive.

"It's obviously quite expensive to deploy these traps on a scale that you would need to make global estimates," Weber said.

The new study takes a different approach. Researchers looked at phosphate, a nutrient taken in by plankton in the surface and released with carbon when particles decompose. They then used a computer model of ocean currents to determine the depth at which this nutrient is released.

"By looking at the products of the decomposition we could look at it in the opposite way but come to the same information, which is how deep stuff gets before it decomposes," Deutsch said.

They found that, overall, about 15 percent of the carbon in ocean plankton makes it to long-term storage in the deep ocean, which agrees with previous estimates. But the regional pattern came as a surprise.

The authors tried to understand why. Temperature could be a factor, since cold water, like refrigerators, will slow decomposition on the way down. But the temperature difference could not fully explain the results.

What did explain a range of observations was the size of the organisms that form marine snow. Warm, nutrient-poor subtropical seas are so-called "marine deserts" where the life that survives is made up of tiny picoplankton.

Nutrient-rich polar oceans, and to a lesser degree the equator, can support larger lifeforms, such as diatoms, that sink more like a proverbial stone.

"Simply because they sink faster, these large phytoplankton are more likely to reach the deep ocean before being consumed," Weber said.

Under climate change, oceans are predicted to support fewer plankton overall. What's more, it's thought that water temperatures will rise, currents will slow and the tropics will expand.

"Even though this study is not directly about climate change, it provides us with a new way of thinking to apply to climate-change scenarios," Weber said.

"As those regions dominated by smaller plankton tend to expand, it's likely that the ocean will become less efficient at locking carbon away from the atmosphere."


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
University of Washington
Water News - Science, Technology and Politics






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

Previous Report
WATER WORLD
PACE will help uncover new information about health of our oceans
Greenbelt MD (SPX) Jul 21, 2016
NASA's Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission is a first-of-its-kind project that aims to answer key questions about the consequences of climate change on the health of our oceans and their relationship with airborne particles and clouds. PACE will use a wide spectrum of wavelengths from an "ocean color" instrument to provide scientists with this information. "PACE repres ... read more


WATER WORLD
Scientists release recommendations for building land in coastal Louisiana

Study: Crumbling school buildings yield crummy scores

Taiwan buses recalled after deadly fire disaster

Ex-Marine 'assassinated' Baton Rouge cops: police

WATER WORLD
Rice's 'antenna-reactor' catalysts offer best of both worlds

'Jumping film' harnesses the power of humidity

Chemists create microscopic and malleable building blocks

Computational design tool transforms flat materials into 3-D shapes

WATER WORLD
Mines hydrology research provides 'missing link' in water modeling

Oceanographers grow, sequence genome of ocean microbe important to climate change

Oceans May be Large, Overlooked Source of Hydrogen Gas

PACE will help uncover new information about health of our oceans

WATER WORLD
A recent pause in Antarctic Peninsula warming

How meltwater from the ice sheets disturbed the climate 10,000 years ago

NASA's Field Campaign Investigates Arctic North American Ecosystems

Warming Arctic could disrupt migration patterns of millions of birds

WATER WORLD
More for less in pastures

Top cocoa grower I.Coast stung by caterpillar invasion

ANU leads effort to develop drought-proof crops

How plants can grow on salt-affected soils

WATER WORLD
Study: Magma buildup threatening Salvadoran capital

Nearly 300 dead or missing from China flooding: media

Anger erupts over government handling of China flood

Three tropical storms building in Pacific: NHC

WATER WORLD
Five missing soldiers found in Nigeria: army

Tide turns against Liberia's biggest slum

Polish millionaire seized in SSudan arms bust, say Spanish police

Mali opens terrorism inquiry after 17 soldiers killed

WATER WORLD
Biologists home in on paleo gut for clues to our evolutionary history

Early humans used mammoth ivory tool to make rope

Technological and cultural innovations amongst early humans not sparked by climate change

Genomes from Zagros mountains reveal different Neolithic ancestry




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






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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