Featured Research

from universities, journals, and other organizations

Rapid climate change and the role of the Southern Ocean

Date:
April 8, 2013
Source:
Cardiff University
Summary:
Scientists have discovered new clues about past rapid climate change. The research concludes that oceanographic reorganizations and biological processes are linked to the supply of airborne dust in the Southern Ocean and this connection played a key role in past rapid fluctuations of atmospheric carbon dioxide levels, an important component in the climate system.

Dust plume off the coast of Argentina imaged using the Spectroradiometer (MODIS) on NASA’s Aqua satellite.
Credit: NASA image created by Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center.

Scientists from Cardiff University and the University of Barcelona have discovered new clues about past rapid climate change.

The research, published this month in the journal Nature Geoscience, concludes that oceanographic reorganisations and biological processes are linked to the supply of airborne dust in the Southern Ocean and this connection played a key role in past rapid fluctuations of atmospheric carbon dioxide levels, an important component in the climate system.

The scientists studied a marine sediment core from the Southern Ocean and reconstructed chemical signatures at different water depths using stable isotope ratios in the shells of foraminifera, single-celled marine organisms. They found that the chemical difference between intermediate level and deep waters over the last 300,000 years closely resembled the changes in atmospheric carbon dioxide levels and the input of windblown dust.

Dr Martin Ziegler, School of Earth and Ocean Sciences, explained: "The deep ocean is by far the largest pool of available carbon on short timescales. In the Southern Ocean, water from the deep rises to the sea surface and comes in contact with the atmosphere. These waters will release their carbon to the atmosphere unless marine phytoplankton captures this carbon through photosynthesis and transports it back into the deep when it dies and sinks. The efficiency of this biological activity in the Southern Ocean is thought to depend on the input of nutrients, namely iron, contained in wind blown dust. It is also this efficiency that determines the strength of chemical stratification in the Southern Ocean."

Professor Ian Hall, School of Earth and Ocean Sciences, added: "Our study finds large changes in chemical stratification of the Southern Ocean not only across the shifts from ice ages to warm interglacial conditions, but also on more rapid, millennial timescales. However, changes in dust flux on these short timescales are much smaller. This could suggest that the biological response to a change in dust input is much more sensitive when the dust flux is relatively low such as it is today. This iron fertilization process might be therefore more important than previously thought."

These findings provide an important benchmark for climate modeling studies and more research will be needed to determine the significance and impact of future changes in dust input into the Southern Ocean.

The research was supported by the Natural Environment Research Council and is part of the international Gateways training network, funded by the 7th Framework Programme of the European Union.


Story Source:

The above story is based on materials provided by Cardiff University. Note: Materials may be edited for content and length.


Journal Reference:

  1. Martin Ziegler, Paula Diz, Ian R. Hall, Rainer Zahn. Millennial-scale changes in atmospheric CO2 levels linked to the Southern Ocean carbon isotope gradient and dust flux. Nature Geoscience, 2013; DOI: 10.1038/ngeo1782

Cite This Page:

Cardiff University. "Rapid climate change and the role of the Southern Ocean." ScienceDaily. ScienceDaily, 8 April 2013. <www.sciencedaily.com/releases/2013/04/130408133752.htm>.
Cardiff University. (2013, April 8). Rapid climate change and the role of the Southern Ocean. ScienceDaily. Retrieved October 22, 2014 from www.sciencedaily.com/releases/2013/04/130408133752.htm
Cardiff University. "Rapid climate change and the role of the Southern Ocean." ScienceDaily. www.sciencedaily.com/releases/2013/04/130408133752.htm (accessed October 22, 2014).

Share This



More Earth & Climate News

Wednesday, October 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) — He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

How Detroit's Money Woes Led To U.N.-Condemned Water Cutoffs

Newsy (Oct. 20, 2014) — The United Nations says water is a human right, but should it be free? Detroit has cut off water to residents who can't pay, and the U.N. isn't happy. Video provided by Newsy
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) — Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) — Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins