Dramatic ocean circulation changes revealed

Dramatic ocean circulation changes revealed
These are shells of a type of foraminifers used in this study. Credit: Cardiff University

The unusually cold weather this winter has been caused by a change in the winds. Instead of the typical westerly winds warmed by Atlantic surface ocean currents, cold northerly Arctic winds are influencing much of Europe.

However, scientists have long suspected that far more severe and longer-lasting cold intervals have been caused by changes to the circulation of the warm Atlantic ocean currents themselves.

Now new research led by Cardiff University, with scientists in the UK and US, reveals that these changes may have been more dramatic than previously thought.

The findings, published today (14 January 2011) in the journal Science, show that as the last Ice Age came to an end (10,000 - 20,000 years ago) the formation of deep water in the North-East Atlantic repeatedly switched on and off. This caused the climate to warm and cool for centuries at a time.

The circulation of the world's ocean helps to regulate the . One way it does this is through the transport of heat carried by vast ocean currents, which together form the 'Great ocean conveyor'. Key to this conveyor is the sinking of water in the North-East Atlantic, a process that causes warm tropical waters to flow northwards in order to replace the sinking water. Europe is kept warmer by this circulation, so that a strong reduction in the rate at which deep water forms can cause widespread cooling of up to 10 degrees Celsius.

Dramatic ocean circulation changes revealed
This is a picture from the research ship. Credit: Cardiff University

Lead author Dr David Thornalley, Cardiff School of Earth and Ocean Sciences, explains how the scientists studied changes in ocean circulation: "We retrieved ocean from the of the Northeast Atlantic which contained the shells of small organisms. We used these shells to examine the past distribution of radiocarbon in the ocean. is a radioactive form of carbon that acts like a natural stopwatch, timing how long it has been since water was last at the sea surface. This allows us to determine how quickly deep water was forming in the Northeast Atlantic at different times in the past."

The team of scientists found that each time deep water formation switched off, the Northeast Atlantic did not fill with water that sank locally. Instead it became inundated with water that had originally formed near Antarctica and then spread rapidly northwards. The new results suggest that the Atlantic ocean is capable of radical changes in how it circulates on timescales as short as a few decades.

Dr Thornalley said: "These insights highlight just how dynamic and sensitive ocean circulation can be. Whilst the circulation of the modern ocean is probably much more stable than it was at the end of the last Ice Age, and therefore much less likely to undergo such dramatic changes, it is important that we keep developing our understanding of the climate system and how it responds when given a push."

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More information: The Science paper 'The Deglacial Evolution of North Atlantic Deep Convection' can be read online at: www.sciencemag.org/journals
Provided by Cardiff University
Citation: Dramatic ocean circulation changes revealed (2011, January 14) retrieved 16 October 2019 from https://phys.org/news/2011-01-ocean-circulation-revealed.html
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Jan 14, 2011
If the Great Flood laid all that down in a few months, the research means nothing. But if God created the earth with a fake history, it is still valid research (so long as god didn't mess up).

I sure wish the creationists could come to a consensus so we know what phenomenon are valid to study.


Jan 14, 2011
Undersea mining will change all of your lives,and none on you are concerned enough to do something about it,and some of you are snickering because you get "Free Money" from "Someone"

Jan 14, 2011
Undersea mining will change all of your lives,and none on you are concerned enough to do something about it,and some of you are snickering because you get "Free Money" from "Someone"

The Monopoly guy?

Maybe we could do something about it, if you were to tell us what it is?

But if you'd do that, then I guess you'd give away your secret and you'd no longer be special; you'd just be another average joe. So I don't suspect you'll be telling us. You need your "reset" to hold over us, and seperate yourself from all us ignorant 'normals'.

Jan 14, 2011
So... climate warming can precipitate climate cooling, at least in the Northern Hemisphere. This is a well know theory, and may be happening right now.

A rapid melt of the artic ice cap might well trigger a new ice age, of 'some' magnitude.

Didn't I read something here recently about a change in N Atlantic currents?

Jan 15, 2011
They didn't mention a lot of things in this story. Like the effects of the melting ice, the salinity of the water,and the effects on the buoyancy of the water, questions of what will happen if you get a big melt off in Iceland for example. Would it shut down the conveyor?

Nope. The shutdown of the conveyor is not probable due to melt water unless something incredibly unlikely and drastic occured.

The Younger Dryas was potentially caused by a massive freshwater gush from the laurentide ice sheet as the world heated up after the last glacial period. The suspected volume of this freshwater was akin to emptying the entire Mississippi and greak lakes systems in a period of weeks. This was enough to disturb the current but not "shut it down". The thermohaline current has an oscillation and varies due to changes in the NAO and Artic Oscillations. "The Day After Tomorrow" won't be comming anytime soon.

Jan 15, 2011
I do not need to keep secrets,and some things I say are obviously not for you,so if the shoe fits as old mothers might say,WEAR THEM.
Its a detailed conversation of how the ocean circulation is designed,how oxygens are part of the conversation and how "Certain Groups" have purposely "Taken" componentry from the system that we need to stay alive here.
Consistent commentary from paid trolls is very easy to spot, they do not ask for information,they run their program as trained.
Grid science guys like myself have been under siege from the "Metal Traders" for a long time now and they are damaging the ability for the rest of us to live here.
Its just a funny,funny to the paid trolls
Without the copper connectors point by point through the planets ground system,energy does not "Flow Through",therefore remove connectors that "Connect the Gulf stream" and the ocean cools and northern Europe will get cooler.
Simple thermographs will point out the "Ground Pin "main nodes" ocean wide.

Jan 15, 2011
"Nope. The shutdown of the conveyor is not probable due to melt water unless something incredibly unlikely and drastic occured."

It doesn't need to be shut down. Altered is all that is needed to effect weather in Europe/Asia.

Jan 15, 2011
a science guy
with classified information from "Our certain Embassy" and I give out just trickles of what I know and do so at poignant times to provoke thought that is not controllable,or is it?

Sound familiar? It's your secret-dispensing policy.

Does it sound crazy to hear it when it's not being vocalized by your mouth?

Jan 16, 2011
How much do you receive per year for your assignment to get your secret mission here completed by being assigned to monitor and troll for your metal master? Dont you think its obvious by now that your continued hammering of some piece of information "harmful" to your masters contentedness is completely visible to others who probably also wonder why you troll here and I out you paid boys and they no longer wonder.
Report me to your master,maybe they could get a more senior agent to take me on,as you are not doing so well and it shows.

Jan 16, 2011
Winners,You can nope all you want,but my "people" who teach grid science to our group are correct.
You should equip yourself of the information of the "New Trench" off the atlantic coast and maybe explain that "Occurence" for our guests here before you are so sure your science "expert" has it all together.
Grid science guys know what really goes on,and I chat to provoke good thinking,but when "Science Interested " folks refuse to 'Pay attention" to all of the events transpiring,they do themselves a dis-service.
All circulation is engineered and when someone loses "Alot of personell" removing a copper line that feeds that conveyor flow and I get a report of those FACTS,you can take it or leave it.
The paid trolls on all of these science sites would manipulate you to believe anything that suited them to silence anyone who understands what our group does.

Jan 16, 2011
Gotcha Doc. I understand you completely.

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