New study questions long-held theories of climate variability in the North Atlantic

October 15, 2015, University of Miami
This figure shows the characteristic 'horseshoe' pattern of Atlantic climate variability (top left panel), along with the time history of this pattern (bottom left). Most previous studies attribute this to changes in the ocean circulation. Our study compares climate models that include ocean circulation (top right) with climate models that have no ocean circulation (bottom right). The two are almost indistinguishable, indicating that the ocean circulation may not play as prominent a role as previously thought. Credit: Credit: Katinka Bellomo, Ph.D., University of Miami Rosenstiel School of Marine and Atmospheric Science

A University of Miami (UM) Rosenstiel School of Marine and Atmospheric-led study challenges the prevailing wisdom by identifying the atmosphere as the driver of a decades-long climate variation known as the Atlantic Multi-decadal Oscillation (AMO). The findings offer new insight on the causes and predictability of natural climate variations, which are known to cause wide-ranging global weather impacts, including increased rainfall, drought, and greater hurricane frequency in many parts of the Atlantic basin.

For decades, research on climate variations in the Atlantic has focused almost exclusively on the role of as the main driver, specifically the Atlantic Meridional Overturning Circulation, which carries warm water north in the upper layers of the and cold water south in lower layers like a large conveyor belt.

"The idea of the ocean as the driver has been a powerful one." said UM Rosenstiel School Professor Amy Clement, the lead author on the study. We used computer models in a new way to test this idea, and find that in fact there is a lot that can be explained without the ocean circulation."

While the overall rise in average temperature of the Atlantic is caused by greenhouse gases, this study examines the fluctuations occurring within this human-related trend. Identifying the main driver of the AMO is critical to help predict the overall warming of the North Atlantic Ocean in coming decades from both natural and man-made climate change. Recent research suggests that an AMO warm phase has been in effect since the mid-1990s, which has caused changes in rainfall in the southeastern US, and resulted in twice as many tropical storms becoming hurricanes than during cool phases.

Using multiple climate models from around the world, Clement's research team removed the ocean circulation from the analysis to reveal that variations in the Atlantic climate were generally the same. The AMO results in a horseshoe-shaped pattern of ocean surface temperatures in the North Atlantic Ocean that have been naturally occurring for the last 1000 years on timescales of 60-80 years. This new analysis shows that the pattern of the AMO can be accounted for by atmospheric circulation alone, without any role for the ocean circulation.

"These results force us to rethink our ability to predict decade-scale temperature fluctuations in the Atlantic and their associated impacts on land. It may be that many of the changes have limited predictability, which means that we should be prepared for a range of outcomes associated with global warming," said Clement.

Amy Clement, Professor of Atmospheric SciencesUniversity of Miami Rosenstiel School of Marine and Atmospheric Science, gives a brief overview of study titled: "The Atlantic Multidecadal Oscillation Without a Role for Ocean Circulation," published Oct. 16, 2015, in the journal Science. Credit: UM Rosenstiel School of Marine and Atmospheric Science

Explore further: Global climate on verge of multi-decadal change

More information: "No evidence for ocean circulation driving Atlantic multidecadal variability," by A. Clement et al. www.sciencemag.org/lookup/doi/ … 1126/science.aab3980

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Returners
1.3 / 5 (13) Oct 15, 2015
I would type "LOL," but that isn't quite what my reaction was.

I just smiled and laid back in my chair for a minute.

Looks like the IPCC knows even less about climate than we thought.
ProcrastinationAccountNumber3659
3.9 / 5 (15) Oct 15, 2015
The IPCC does not do any research, it only uses published research and attempts to summarize it. They can only know what the scientific community has communicated. I do not think they ever claim to know anything for sure and I they try to quantify their levels of uncertainty.

jeffensley
1.6 / 5 (13) Oct 15, 2015
For decades, research on climate variations in the Atlantic has focused almost exclusively on the role of ocean circulation as the main driver


Decades eh? Sounds settled... toss this new garbage research out.
Bongstar420
2.3 / 5 (12) Oct 15, 2015
Thats right...plan for it to be wetter or drier due to "global warming"

or

more wind or less wind

or

hotter or colder
Eddy Courant
2.1 / 5 (14) Oct 15, 2015
What Bongstar420 said.
EricHa
1.5 / 5 (8) Oct 15, 2015
New improved [s]FAT[/s]AMO free, [s]Sugar[/s]Solar free models for all the family
Even better than the real thing. You know it makes sense.
Returners
1.4 / 5 (9) Oct 15, 2015
This year we've had a dry spell and a very hot fall so far in Louisiana, but that's because of El Nino changing prevailing winds. In neutral and la nina years we have more winds from the south east. In el nino we get dry winds from the west and north.

Today the high temperature in Hammond was 95f, which may be a new record, but if it is not going to be the record heat index, because it's a "dry heat". the humidity is absurdly low for Louisiana norms. Forecast for tomorrow is 94f, which again is almost the record.

I attribute this to randomness and a combination of dry spells plus el nino.

This is nothing compared to 2004 over all. 2004 was very hot and very dry. Hottest, driest year I can remember. We were constantly watering the grass and the garden, and the grass was dying anyway because the water just evaporated or soaked up as fast as you could run the hose.

This year grass did "ok" but now it's time for it to start browning anyway, so hard to say.
Returners
1.4 / 5 (9) Oct 15, 2015
We normally need 1 or 2 weak tropical storms to come in and break the dry spells in like august or september, but this year el nino didn't let anything happen due to insane shear over gulf.

There is supposed to be a wave forming in the E.pac which si going to cross central america and mexico and come in the gulf, but the shear is probably just going to drive it into florida as a patch of random scattered showers.

It would be nice if it came to Louisiana and gave us like a good two day, 5-10 inch soaking. For those who don't know, we can handle that here due to not a lot of hills, and sandy soil and runoff just works out. So we need lots of rain to keep soil moist and keep humidiy.

Low humidity means higher temperature swings, but again this isn't GW, it's just a random "miss" of not having any tropical waves or storms come anywhere near us this year. It seems to happen about once or twice per decade.
Returners
1.4 / 5 (9) Oct 15, 2015
NOAA outlook claims south is going to get wetter than average and cooler than average winter.

I hope so. Maybe we'll get some snow or something too, like 2008, or those two cold spells where I had 18 inch long icicles...biggest I've ever seen in person in Louisiana. It used to do that around here in like the 60's and 70's (older people say) and then it sort of stopped in the 80's and 90's, but now it looks like the old pattern might be coming back.

They have been wrong before though. Few years back they incorrectly predicted ENSO cycle like 6 times in a row.
richard_f_cronin
1.6 / 5 (7) Oct 16, 2015
Before we stumble any further along this dead end called Anthropogenic Global Warming, I just hope the serious scientific work of geophysicists and nuclear physicists would come forward faster regarding the reality of naturally-occuring nuclear fission, within the cores of all planets, large moons, and stars. Dr. Paul Kuroda, Dr. D.F. Hollenbach, Robert J. Tuttle, Dr. Anke Wohler, Richartd W. Carlson, J. Marvin Herndon, Dr. Padmanabha Rao, Dr. Stephen T. Dye.
EnricM
5 / 5 (8) Oct 16, 2015
The IPCC does not do any research, it only uses published research and attempts to summarize it. They can only know what the scientific community has communicated. I do not think they ever claim to know anything for sure and I they try to quantify their levels of uncertainty.


Wrong! The IPCC is Evil, go google it, I got 510.000 results googling for "IPCC is EVIL" hence it must be true.
And everybody knows that the IPCC's hidden agenda is to reinforce Obama's Coup de Etat using HAARP and chemtrails to change the climate and then claime it was human induced global warming. And all this is aimed at taking away the guns of the hones working American Patriot and force us to interracial gay marriage and secretly injecting mariguanas saying that it is vaccinations.

ProcrastinationAccountNumber3659
3 / 5 (6) Oct 16, 2015
@EnricM LMAO that is great! I got 512000 results.
antigoracle
2 / 5 (8) Oct 16, 2015
Using multiple climate models from around the world...

Well...duh... If the climate models says so, then it must be true and decades of research saying it's the ocean, must be wrong.
EnricM
5 / 5 (3) Oct 16, 2015
Before we stumble any further along this dead end called Anthropogenic Global Warming, I just hope the serious scientific work of geophysicists and nuclear physicists would come forward faster regarding the reality of naturally-occuring nuclear fission, within the cores of all planets, large moons, and stars. Dr. Paul Kuroda, Dr. D.F. Hollenbach, Robert J. Tuttle, Dr. Anke Wohler, Richartd W. Carlson, J. Marvin Herndon, Dr. Padmanabha Rao, Dr. Stephen T. Dye.


You forget Dr Frankenfurter, Dr No and Dr Alimantado !! https://www.youtu...Ai2FfPhw
SuperThunder
4 / 5 (8) Oct 16, 2015
I just googled "Jesus causes climate change."

1,560,000 results.

We may have to put an emissions cap on churches.
mreda14
2 / 5 (4) Oct 16, 2015
I do not know what this crazy idea of ocean circulation is got to do with climate change due to air pollution which is caused by the industrial revolution from China , India and the United States and deforestation in the Amazon This problem of Climate change is a global problem.These people how owns these polluted industry got lots of money they buy the media ( newspaper and TV).
Captain Stumpy
5 / 5 (1) Oct 19, 2015
We may have to put an emissions cap on churches.
"amen" !!

.

.

ROTFLMFAO

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