Oceanic seesaw links Northern and Southern hemisphere during abrupt climate change

Feb 25, 2009

Very large and abrupt changes in temperature recorded over Greenland and across the North Atlantic during the last Ice Age were actually global in extent, according to an international team of researchers led by Cardiff University.

New research, published in the journal Nature today, supports the idea that changes in ocean circulation within the Atlantic played a central role in abrupt climate change on a global scale.

Using a sediment core taken from the seafloor in the South Atlantic, the team were able to create a detailed reconstruction of ocean conditions in the South Atlantic during the final phases of the last ice age.

Dr Stephen Barker, Cardiff University's School of Earth and Ocean Sciences and lead author on the paper, said: "During this period very large and abrupt changes in temperature were observed across the North Atlantic region. However, evidence for the direct transmission of these shifts between the northern and southern hemispheres has so far been lacking".

The new study suggests that abrupt changes in the north were accompanied by equally abrupt but opposite changes in the south. It provides the first concrete evidence of an immediate seesaw connection between the North and South Atlantic. The data shows, for example, that an abrupt cooling in the north would be accompanied by a rapid southerly shift of ocean fronts in the Southern Ocean, followed by more gradual warming across the south.

Dr Barker explains: "The most intuitive way to explain these changes is by varying the strength of ocean circulation in the Atlantic. By weakening the circulation, the heat transported northwards would be retained in the south."

Climate physicist, Dr Gregor Knorr, co-author of the study and now based at the Alfred Wegener Institute in Germany, said: "Our new results agree with climate models that predict a rapid transmission of climate signals between the two hemispheres as a consequence of abrupt changes in ocean circulation."

The study has wide implications for our understanding of abrupt climate change. Dr Ian Hall, School of Earth and Ocean Sciences, said: "While it is unlikely that an abrupt change in climate, related to changes in ocean circulation, will occur in the near future, our results suggest that if such an extreme scenario did occur, its effects could be felt globally within years to decades."

More information: 'Interhemispheric Atlantic seesaw response during the last deglaciation' is published in Nature on 26 February 2009.

Source: Cardiff University

Explore further: NASA balloons begin flying in Antarctica for 2014 campaign

add to favorites email to friend print save as pdf

Related Stories

Fingers pointed as climate talks deadlock

1 hour ago

Accusations flew at deadlocked UN climate talks in Lima on Saturday, as the United States warned that failure to compromise could doom the 22-year-old global forum.

Fun cryptography app pleases students and teachers

11 hours ago

Up on Google Play this week is Cryptoy...something that you might want to check out if you or someone you know wishes entry into the world of cryptography via an educational and fun app. You learn more about ciphers and keys; you ...

Recommended for you

Scientists make strides in tsunami warning since 2004

18 hours ago

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

19 hours ago

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 8

Adjust slider to filter visible comments by rank

Display comments: newest first

jonnyboy
1.8 / 5 (5) Feb 25, 2009
and THIS is NEWS?

only in NATURE, a leading GCW hoax rag
thermodynamics
3 / 5 (4) Feb 25, 2009
jonnyboy said:
and THIS is NEWS?

only in NATURE, a leading GCW hoax rag


I have no idea who you are, but Nature is a journal that has very difficult standards for acceptance. Anything published in Nature had better be paid attention to.

As for the surprise that this is news, it shows that you either didn't read the article or didn't understand it (I'm betting you just don't have the capacity to understand it). This article is confirmation for an important perspective that changes in ocean circulation can have a rapid effect on climate. Yes, it has been discussed but it now has evidence to support the theory.

Then you jump to the idea that the article is feeding into the "GCW hoax." The article is probably not about AGW or GCW since the few humans that were around were not burning much of anything (but you probably didn't read it closely enough to notice that the climate change took place thousands of years ago). :-)

Second, it is saying that climate change can take place abruptly without involving a change in the global mean temperature. Instead, heat transfer was slowed from South to North by a balancing act of flow instead of a global temperature rise. For anyone who does not believe the earth is warming this would be good news since it shows how hemispheric temperature swings can occur even without a change in mean temperature (but then you apparently cannot read).

I guess any good research associated with climate is just a subject that makes you react with some diatribe and invective without your even having to read the article (or without the ability to understand what was written). Please try to read the article and then make a comment. ;-)
Egnite
1 / 5 (1) Feb 26, 2009
So it's clear, all we need to do to stop GW is build a wall that seperates the oceans of the northern and southern hemispheres :-) No more green taxes, just ocea seperating taxes.

This would remove the north and south sea saw and replace it with two sea saws, one in northern hemisphere and one in the south. Which in turn should coz the poles to get colder as I can't see it being possible for the equator to get colder.

Jobs a good een! Just need to prove GW is a real problem 1st and not just a tax scam then we should go ahead with it! lawl
AMMBD
3 / 5 (1) Feb 26, 2009
http://www.physor...298.html
http://www.physor...458.html

interesting that this article came out about when the above 2 did.

one does have to wonder, are we really warming or are we really cooling or some combination of both.
thermodynamics
3.7 / 5 (3) Feb 26, 2009
AMMBD: The articles you pointed out are unrelated to the article here since the article here is talking about prehistoric flows of energy when the articles you included are talking about present changes in ice mass. As for your question about warming, cooling, or both, it is a good one. There are always natural forces changing the earth's temperature in both directions. There are also forces redistributing energy. The question that seems to have everyone frantic is the one of human influence on warming. The balance seems to be warming now (in spite of claims cooling) and the question of how much of the warming is human induced is still being sorted out.
jonnyboy
1 / 5 (3) Feb 28, 2009
thermo "
I have no idea who you are, but Nature is a journal that has very difficult standards for acceptance. Anything published in Nature had better be paid attention to."

You just keep on telling yourself that, exactly what color is the sky in your world?
thermodynamics
3 / 5 (2) Feb 28, 2009
jonnyboy: Let's try it this way. Nature is a journal that has been considered one of the world's leading journals for science of all types since its inception in 1869. It has published pivotal articles on electromagnetism, quantum mechanics, genetics, geology, paleontology, astronomy, weather, archeology, mathematics, and many other subjects. It is very highly cited as a reference (that is how journals are measured). It and "Science" are the two journals that good scientists try to publish in (these are considered the best for the career of any scientist). However, both journals have very strict standards and are very difficult to have an article accepted for publication. For those reasons I consider Nature and Science to be the best of the scientific journals for publication.

Now, why don't you tell me what you consider to be a "good" publication (and Mad magazine does not count). ;-) I'm sure you will have a factual rejoinder, not just fluff like "what color is the sky in your world?"
rubberman
5 / 5 (1) Mar 01, 2009
I personally like NG and AMerican scientist, although occasionally playboy churns out a real gem...

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.