Featured Research

from universities, journals, and other organizations

University Of California Study Sheds New Light On Climate-change Processes

Date:
March 11, 2004
Source:
University Of California - Davis
Summary:
A new study from the University of California shows, for the first time, that the deep-ocean circulation system of the north Atlantic, which controls ice-age cycles of cold and warm periods in the Northern Hemisphere, is integrally coupled to salinity levels in the Caribbean Sea.

A new study from the University of California shows, for the first time, that the deep-ocean circulation system of the north Atlantic, which controls ice-age cycles of cold and warm periods in the Northern Hemisphere, is integrally coupled to salinity levels in the Caribbean Sea.

This research reinforces concerns that global warming, by melting the glacial ice of Greenland, could quickly and profoundly change salinity and temperatures in the north Atlantic Ocean. One consequence might be much colder weather in northern Europe and Britain and perhaps even in eastern Canada and the U.S. northeast.

The study is published by the journal Nature in its online edition today (March 10) and its print edition tomorrow. The authors are graduate student Matthew Schmidt and geology professor Howard Spero of UC Davis, and geology professor David Lea of UC Santa Barbara.

During Earth's warm periods, like the present one, surface ocean currents transport heat from the tropics to the cool northern latitudes. The new data, a record of Caribbean salinity for the past 120,000 years, show that when the northern hemisphere warmed, Caribbean salinity levels dropped.

The authors hypothesize that elevated Caribbean salinity, which is transported via the Gulf Stream to the north Atlantic, amplifies the heat transport system by increasing the deep-ocean circulation rate. When the North Atlantic cools, Caribbean salinity builds up because the deep ocean circulation drops to a fraction of its previous rate and the Gulf Stream no longer transports salty water away.

If Caribbean salinity helps power the heat-transport system, then what might happen if melting ice from Greenland dilutes the salinity of the north Atlantic at a time when Caribbean salinity is low, like today?

"Our atmospheric and oceanic systems are integrally linked," Spero said. "Unnatural climate perturbations, such as global warming, can impact ocean circulation and nudge the system towards a threshold that could produce an abrupt climatic change."

Spero and Lea have a long collaboration in using chemical analyses of the fossil shells of tiny sea animals, called foraminifera, to reconstruct Earth's climate.

In their new study, they teamed up with Schmidt, Spero's Ph.D. student, to analyze fossil foraminifera to reconstruct the rise and fall of the temperature and salinity of the Caribbean Sea throughout the last full ice-age cycle, when huge glaciers reached far south into North America and Europe.

They then compared those salinity cycles with published reconstructions of ice-age oscillations of deep Atlantic Ocean circulation patterns. The correlations were striking.

"I don't believe the Earth can plummet into an ice age today," Spero said. "But human-caused global warming has the ability to affect climate in ways we haven't seen before and do it very quickly."

A paper that refers to similar events occurring today was recently published in the journal Nature by an international group of scientists led by Ruth Curry of Woods Hole Oceanographic Institute in Massachusetts.

Curry's study showed that in the past 50 years, salinity in the tropical Atlantic Ocean has risen and salinity in the north Atlantic has fallen. That is the pattern that Schmidt, Spero and Lea say has led to colder climates in the past. "We present a historical analog to the salinity buildup that is observed in the tropics today by Dr. Curry and others," said Spero and Lea.

###The University of California study was funded by the USSSP Schlanger Ocean Drilling Graduate Fellowship and grants from the U.S. National Science Foundation.

More information:

Spero home page: http://www-geology.ucdavis.edu/faculty/spero.html

Lea home page: http://www.geol.ucsb.edu/faculty/lea/

Nature: http://www.nature.com/

Schlanger Ocean Drilling Graduate Fellowship: http://www.joiscience.org/USSSP/default.html


Story Source:

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


Cite This Page:

University Of California - Davis. "University Of California Study Sheds New Light On Climate-change Processes." ScienceDaily. ScienceDaily, 11 March 2004. <www.sciencedaily.com/releases/2004/03/040311071131.htm>.
University Of California - Davis. (2004, March 11). University Of California Study Sheds New Light On Climate-change Processes. ScienceDaily. Retrieved August 22, 2014 from www.sciencedaily.com/releases/2004/03/040311071131.htm
University Of California - Davis. "University Of California Study Sheds New Light On Climate-change Processes." ScienceDaily. www.sciencedaily.com/releases/2004/03/040311071131.htm (accessed August 22, 2014).

Share This




More Earth & Climate News

Friday, August 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Airlines on Iceland Volcano Alert

Airlines on Iceland Volcano Alert

Reuters - Business Video Online (Aug. 22, 2014) Iceland evacuates an area north of the country's Bardarbunga volcano, as the country's civil protection agency says it cannot rule out an eruption. Authorities have already warned airlines. As Joel Flynn reports, ash from the eruption of the Eyjafjallajokull volcano in 2010 shut down much of Europe's airspace for six days. Video provided by Reuters
Powered by NewsLook.com
Endangered Red Wolves Face Uncertain Future

Endangered Red Wolves Face Uncertain Future

AP (Aug. 22, 2014) A federal judge temporarily banned coyote hunting to save endangered red wolves, but local hunters say that the wolf preservation program does more harm than good. Meanwhile federal officials are reviewing its wolf program in North Carolina. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Coal Gas Boom in China Holds Climate Risks

Coal Gas Boom in China Holds Climate Risks

AP (Aug. 22, 2014) China's energy revolution could do more harm than good for the environment, despite the country's commitment to reducing pollution and curbing its carbon emissions. (Aug. 22) Video provided by AP
Powered by NewsLook.com
Microbrewery Chooses Special Can for Its Beer

Microbrewery Chooses Special Can for Its Beer

AP (Aug. 22, 2014) Aluminum giant, Novelis, has partnered with Red Hare Brewing Company to introduce the first certified high-content recycled beverage can. (Aug. 22) Video provided by AP
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:
from the past week

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