Stronger west winds blow ill wind for climate change

July 10, 2018, University of New South Wales
Credit: CC0 Public Domain

Stronger westerly winds in the Southern Ocean could be the cause of a sudden rise in atmospheric CO2 and temperatures in a period of less than 100 years about 16,000 years ago, according to a study published in Nature Communications.

The during that event strengthened as they contracted closer to Antarctica, leading to a domino effect that caused an outgassing of from the Southern Ocean into the atmosphere.

This contraction and strengthening of the winds is very similar to what we are already seeing today as a result of human caused change.

"During this earlier period, known as Heinrich stadial 1, atmospheric CO2 increased by a total of ~40ppm, Antarctic surface atmospheric temperatures increased by around 5°C and Southern Ocean temperatures increased by 3°C," said lead author Dr. Laurie Menviel, a Scientia Fellow with the University of New South Wales (Sydney).

"With this in mind, the contraction and strengthening of westerly winds today could have significant implications for atmospheric CO2 concentrations and our future climate."

Scientists know changes in atmospheric dioxide have profound impacts on our climate system. This is why researchers are so interested in Heinrich events, where rapid increases in atmospheric carbon dioxide occur over a very short period of time.

Heinrich event 1, which occurred about 16,000 years ago, is a favorite to study because alterations in ocean currents, temperature, ice and sea levels are clearly captured in an array of geological measures. This allows theories to be tested against these changes.

Until now, many of the propositions put forward for the carbon dioxide spike struggled to explain its timing, rapidity and magnitude.

But when the researchers used climate models to replicate an increase in the strength of westerly winds as they contracted towards the Antarctic, the elements began to align. The stronger winds caused a domino effect that not only reproduced the increase in atmospheric carbon dioxide but also other changes seen during Heinrich 1.

The stronger winds had a direct impact on the circulation, increasing the formation of bottom water along the Antarctic coast and enhancing the transport of carbon rich waters from the deep Pacific Ocean to the surface of the Southern Ocean. As a result, about 100Gt of carbon dioxide was emitted into the atmosphere by the Southern Ocean.

Today, observations suggest westerly winds are again contracting southwards and getting stronger in response to the warming of our planet.

"The carbon exchange in particular between the Southern Ocean and the atmosphere matter deeply for our climate. It is estimated the Southern Ocean absorbs around 25% of our atmospheric carbon emissions and that ~43% of that carbon is taken up by the Ocean south of 30S," said Dr. Menviel.

"With westerly winds already contracting towards Antarctica, it's important to know if this event is an analogue for what we may see in our own future.

"For this reason, it is vital to bring more observational networks into the Southern Ocean to monitor these changes. We need a clear warning if we are approaching a point in our climate system where we may see a spike in and the rapid temperature rise that inevitably follows."

Explore further: Southern Ocean resistant to changing winds

More information: L. Menviel et al, Southern Hemisphere westerlies as a driver of the early deglacial atmospheric CO2 rise, Nature Communications (2018). DOI: 10.1038/s41467-018-04876-4

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15 comments

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aksdad
1 / 5 (3) Jul 11, 2018
Then again, maybe not, since scientists have no way to know wind circulation patterns 16,000 years ago. Every conclusion of this study is simply speculation. Validating those theories with climate models is a classic case of circular reasoning. They tweak the inputs of the computer program to give the results they expect, then tell us the model validates the theory. Anyone else see a problem with that?

Modeling the complex, non-linear and chaotic global climate is fraught with difficulty. It is impossible to model it with enough precision to make even modestly accurate predictions.
leetennant
5 / 5 (6) Jul 11, 2018
Modeling the complex, non-linear and chaotic global climate is fraught with difficulty. It is impossible to model it with enough precision to make even modestly accurate predictions.


"Because we can't know everything, we know nothing and should therefore have our minds open to anything" is a classic tenet of pseudoscience and snakeoil salesman.
PTTG
4.7 / 5 (3) Jul 11, 2018
@Aksdad What's your doctorate in?
zz5555
5 / 5 (4) Jul 11, 2018
Modeling the complex, non-linear and chaotic global climate is fraught with difficulty. It is impossible to model it with enough precision to make even modestly accurate predictions.


"Because we can't know everything, we know nothing and should therefore have our minds open to anything" is a classic tenet of pseudoscience and snakeoil salesman.

I think the fact that climate models have been so accurate and successful disproves aksdad's claims. Claiming that the long term climate is chaotic and cannot be modeled is, perhaps, one of the greatest myths of the anti-science movement.
TrollBane
5 / 5 (2) Jul 13, 2018
"@Aksdad What's your doctorate in?" Judging by his refusal to learn, probably its in proctology.
snoosebaum
1 / 5 (1) Jul 14, 2018
So CO2 comes from the oceans then ? Seems to me they need to sort cause and effect ,, could be a wee bit tricky
snoosebaum
1 / 5 (1) Jul 14, 2018
of course he can , like everyone does , like algore

http://www.denmar...-weather
Zzzzzzzz
5 / 5 (1) Jul 14, 2018
"@Aksdad What's your doctorate in?" Judging by his refusal to learn, probably its in proctology.


And in this case, self examined proctology....using his head, forget the hands.....
zz5555
5 / 5 (2) Jul 14, 2018
So CO2 comes from the oceans then ? Seems to me they need to sort cause and effect ,, could be a wee bit tricky.

That depends. Warmer oceans can hold less CO2. So in the event discussed in the article, the Southern Ocean warmed and released CO2. On the other hand, during the current global warming, the oceans are still cool enough to absorb some of the CO2 generated by humans (about half, as I recall). As the oceans warm, though, they will absorb less and less CO2 until they finally start emitting some of the CO2 back into the atmosphere. That will be a nasty bit of feedback.

Cause and effect is pretty well understood for the current warming. Past warming (and cooling) events still have some interesting things to teach us.
snoosebaum
1 / 5 (1) Jul 14, 2018
like CO2 follows warming not the reverse
zz5555
5 / 5 (2) Jul 14, 2018
like CO2 follows warming not the reverse

It's extremely well known and well understood that increases in atmospheric CO2 can both precede warming and follow warming. The increases precede warming when, for example, fossil fuels are burned. This can happen naturally, like the Siberian Traps that caused the end-Permian extinction, or can be man-made, like is known to be causing the current warming.

It is so incredibly obvious that humans burning fossil fuels could cause atmospheric CO2 levels to increase prior to any warming that in order to deny that basic fact one must be determined to be willfully ignorant, or one must be amazingly incompetent. Your bringing up the silliness (and the recent idiocy of no-sea-level-rise-due-to-global-warming-because-water-won't-flow-uphill) suggests that you're either one of those or are acting like a troll or Poe). I suspect you're just a troll and are a waste.
SteveS
5 / 5 (2) Jul 15, 2018
like CO2 follows warming not the reverse

"Sometimes a house gets warmer even when the central heating is turned off. Does this prove that its central heating does not work? Of course not "

https://www.newsc...warming/
SteveS
5 / 5 (2) Jul 15, 2018
like CO2 follows warming not the reverse

"This proves that rising CO2 was not the trigger that caused the initial warming at the end of these ice ages – but no climate scientist has ever made this claim. It certainly does not challenge the idea that more CO2 heats the planet. "

https://www.newsc...warming/
snoosebaum
1 / 5 (1) Jul 16, 2018
https://www.newsc...warming/

nice charts , lol
SteveS
5 / 5 (1) Jul 17, 2018
https://www.newscientist.com/article/dn11659-climate-myths-ice-cores-show-co2-increases-lag-behind-temperature-rises-disproving-the-link-to-global-warming/

nice charts , lol

Try reading the text, you may learn something.

Did you notice the date on the article? 2007, and yet you still cling to the same debunked argument.

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