Deep oceans can mask global warming for decade-long periods

Sep 18, 2011

The planet's deep oceans at times may absorb enough heat to flatten the rate of global warming for periods of as long as a decade even in the midst of longer-term warming, according to a new analysis led by the National Center for Atmospheric Research (NCAR).

The study, based on of , points to ocean layers deeper than 1,000 feet (300 meters) as the main location of the "missing heat" during periods such as the past decade when global showed little trend. The findings also suggest that several more intervals like this can be expected over the next century, even as the trend toward overall warming continues.

"We will see global warming go through hiatus periods in the future," says NCAR's Gerald Meehl, lead author of the study. "However, these periods would likely last only about a decade or so, and warming would then resume. This study illustrates one reason why global temperatures do not simply rise in a straight line."

The research, by scientists at NCAR and the Bureau of Meteorology in Australia, will be published online on September 18 in Nature . Funding for the study came from the National Science Foundation, NCAR's sponsor, and the Department of Energy.

Where the missing heat goes

The 2000s were Earth's warmest decade in more than a century of weather records. However, the single-year mark for warmest global temperature, which had been set in 1998, remained unmatched until 2010.

Yet emissions of continued to climb during the 2000s, and showed that the discrepancy between incoming sunshine and outgoing radiation from Earth actually increased. This implied that heat was building up somewhere on Earth, according to a 2010 study published in Science by NCAR researchers Kevin Trenberth and John Fasullo.

The two scientists, who are coauthors on the new study, suggested that the oceans might be storing some of the heat that would otherwise go toward other processes, such as warming the atmosphere or land, or melting more ice and snow. Observations from a global network of buoys showed some warming in the upper ocean, but not enough to account for the global build-up of heat. Although scientists suspected the deep oceans were playing a role, few measurements were available to confirm that hypothesis.

To track where the heat was going, Meehl and colleagues used a powerful software tool known as the Community Climate System Model, which was developed by scientists at NCAR and the Department of Energy with colleagues at other organizations. Using the model's ability to portray complex interactions between the atmosphere, land, oceans, and sea ice, they performed five simulations of global temperatures.

The simulations, which were based on projections of future greenhouse gas emissions from human activities, indicated that temperatures would rise by several degrees during this century. But each simulation also showed periods in which temperatures would stabilize for about a decade before climbing again. For example, one simulation showed the global average rising by about 2.5 degrees Fahrenheit (1.4 degrees Celsius) between 2000 and 2100, but with two decade-long hiatus periods during the century.

During these hiatus periods, simulations showed that extra energy entered the oceans, with deeper layers absorbing a disproportionate amount of heat due to changes in oceanic circulation. The vast area of ocean below about 1,000 feet (300 meters) warmed by 18% to 19% more during hiatus periods than at other times. In contrast, the shallower global ocean above 1,000 feet warmed by 60% less than during non-hiatus periods in the simulation.

"This study suggests the missing energy has indeed been buried in the ocean," Trenberth says. "The heat has not disappeared, and so it cannot be ignored. It must have consequences."

A pattern like La Nina

The simulations also indicated that the oceanic warming during hiatus periods has a regional signature. During a hiatus, average sea-surface temperatures decrease across the tropical Pacific, while they tend to increase at higher latitudes, especially around 30°S and 30°N in the Pacific and between 35°N and 40°N in the Atlantic, where surface waters converge to push heat into deeper oceanic layers.

These patterns are similar to those observed during a La Niña event, according to Meehl. He adds that El Niño and La Niña events can be overlaid on top of a hiatus-related pattern. tend to drop slightly during La Niña, as cooler waters reach the surface of the tropical Pacific, and they rise slightly during El Niño, when those waters are warmer.

"The main hiatus in observed warming has corresponded with La Niña conditions, which is consistent with the simulations," Trenberth says.

The simulations were part of NCAR's contribution to the Coupled Model Intercomparison Project Phase 5 (CMIP5). They were run on supercomputers at NCAR's National Science Foundation-supported Climate Simulation Laboratory, and on supercomputers at Oak Ridge Leadership Computing Facility and the National Energy Research Scientific Computing Center, both supported by the Office of Science of the U.S. Department of Energy.

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User comments : 16

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Noumenon
4.5 / 5 (60) Sep 18, 2011
There is a collosal difference between duck-taping a model to fit observations and predicting phenomena before hand from the model. One is science.
omatumr
1.3 / 5 (15) Sep 18, 2011
Global Warming Not Masked!

The threat of nuclear war gave birth to Hippies and to secret agreements among world leaders to endorse the Bilderberg model of a stable H-filled Sun and global climate change as the common enemy to unite nations and promote world peace [1]:

1. "Historical roots of Climategate"

http://en.wikiped..._Mao.jpg

http://dl.dropbox...oots.pdf

http://dl.dropbox...oots.doc

But Earth is heated by a variable star, powered by neutron repulsion in its neutron-rich core. That is why Earth's climate has always changed and life continues to evolve [2]:

2. "Origin and evolution of life"

http://dl.dropbox...5079.pdf

Fanaticism replaced consensus science when errors were found in claims we caused global climate change [3]:

3. Meteorologist Director fired!

www.climategate.c...ekes.pdf

Oliver K. Manuel
tigger
3 / 5 (10) Sep 18, 2011
Human beings defy physics and have no impact on the physical environment what-so-ever. They also are responsible for the existence of reality because they observe things and collapse waveforms because the collection of atoms that they are comprised of are different from all the other atoms in the universe.

:P
deatopmg
2.3 / 5 (16) Sep 18, 2011
ANother Trenberth model jury rigged to fit the data. Sigh!
AkiBola
2.5 / 5 (11) Sep 18, 2011
The reverse would also be true then. Deep oceans mask the effect of global cooling. Stock up on warm blankets and hot chocolate, just in case.
gimpypoet
1.7 / 5 (11) Sep 18, 2011
Key word is "simulation". stop the hype about global warming. the earth's natural cycle will prevail no matter human influence of any kind, positive or negative. there may be some truth in what we beleive shaping events and should be experimented with. we should all wish for an end to all ignorance at 7:00 pm on tuesday 20, 2011, just to try it out. the hippies did not push global warming, the republican nixon did. hippies hated nixon, first for ramping up the war, second for his treasonous acts in office he resigned from. he caused oil to skyrocket, which lined the pockets of he and his republican buddies. party politics is killing the country. lets turn our attention to forcing politicians to do their jobs, if they fail to do them, fire them like you would be fired if you failed, and refuse to pay them if they refuse.
PaulRadcliff
3.9 / 5 (19) Sep 18, 2011
Are all your posters on crack?? Climate change is undeniably real, it is happening, the evidence is the gradually less polar ice re-freeze in Winter, every year. Summers thaw each pole's ice more than it is re-frozen each subsequent Winter. These are facts. Explaining away scientific fact is more akin to moral Creationists, not intelligent, objective and independent thinkers, like 98% of Climatologists, globally.
It's like claiming that a person of less than average intelligence is always smarter than Albert Einstein! Get an education, already!
astro_optics
1 / 5 (5) Sep 18, 2011
AkiBola DITTO!
vidar_lund
4.6 / 5 (11) Sep 19, 2011
@Paul Radcliff
Are all your posters on crack??

Dude, give it up. This forum is full of loonies. It could have been an interesting site but it gets kind of tiring having to filter through 95% crap in each tread. Unfortunately the modern society has given people the idea that everyone is entitled to their own facts. Also actual education and knowledge about the subjects doesn't seem to be a requirement either.
Jeddy_Mctedder
1.8 / 5 (12) Sep 19, 2011
people who believe in climate change as if it were a one of the laws of physics that has been tested under controlled laboratory conditions , rigorously, and under multiple testing models with various instruments simply do not understand the empirical subject of climate science ----a giant dynamic system called planet earth , a system which is massive.

of course we all know they will reply to a statement like this as if it is a ciggarette company spokesperson saying to the public that the 'science is not totally in' about ciggarette smoking being unhealthy. but climate science and global warming are not the same battle as that fought by big tobacco to continue selling poison.

fossil fuels are NOT smoking ciggaretts. C02 is not a poison.

the climate is not predictable as a small non-dynamic closed system is. simply put it is NOT predictable-----i support funding of climate science. but not alarmist apocalyptic preaching of the second coming.
lengould100
4.7 / 5 (7) Sep 19, 2011
i support funding of climate science. but
That's not the question anywhere. Where do you stand regarding taking significant action to mitigate a POSSIBLE serious problem for our grandkids and on? That's the key question. I think there's enough information available (primarily the simple physics of how GHG's operate) to justify doing everything affordable to reduce emissions at least until the climate science is certain.
omatumr
1 / 5 (7) Sep 19, 2011
International agreements among world leaders in the early 1970s:

http://en.wikiped..._Mao.jpg

1. Assumed the validity of the
a.) Bilderberg Sun as a stable heat source, and
b.) Earth-centered model of global climate change

2. And agreed to work together to
c.) Unite nations
d.) Avoid nuclear war
e.) End the space race
f.) Stop global climate change [1]

Experimental measurements [2] falsify
both assumptions (a) and (b)

1. "Deep Roots of Climategate" (2011)

http://dl.dropbox...oots.pdf

2. "Neutron Repulsion", The
APEIRON Journal, in press (2011)

http://arxiv.org/...2.1499v1
Ethelred
5 / 5 (3) Sep 19, 2011
I see you can't answer Oliver.

What is so difficult about answering questions? Reality have your tongue?

I know why you can't answer the questions. The answer is that you are wrong on neutron repulsion and you have to create a vast conspiracy to protect your tender ego.

Baby steps Oliver.

1] Did you read the letter you linked to?
2] Why did you link to it?
3] What was it supposed to show?
4] Since it doesn't support the claim of conspiracy you need to admit that you were wrong about the link
6] You have the power to admit you could be wrong on this
7] You do not have the power to create a conspiracy where there never was one
8] You should write an apology on all the threads you posted that crap on
9] You should apologize to all the politicians you falsely accused
10] You apologize to all the scientists you accused
11] You should apologize to all the people you gave unwarranted ones to
12] You should promise YOURSELF not to Crank again.

A nice 12 step program

Ethelred
GSwift7
1 / 5 (2) Sep 20, 2011
PaulRadcliff:

Summers thaw each pole's ice more than it is re-frozen each subsequent Winter. These are facts


Can you provide a link showing that what you claim is true for the South Pole?

Also, the North Pole and Greenland seem to have been largely free of ice prior to industrialization and then froze back over again in relatively recent geological times such as the MWP.

As for the ocean hiding warming, why would it hide warming now, and not in previous decades? If it is capable of hiding the warming now, then what does that say about the confidence we can have in measuring warming by measuring lower troposphere air temperatures? How did they come up with a ten year time frame?

Whether you like it or not, this article is simply an attempt to sustain confidence in mainstream climate science in response to predictions failing in the past 10 years.

It snowed in the Alps yesterday, at 1200 ft. A bit early for that, since it's still Summer.
GSwift7
1 / 5 (2) Sep 20, 2011
To PaulRadcliff again:

Are all your posters on crack??


adhom attack.

Climate change is undeniably real, it is happening


Straw man. Climate obviously changes. Nobody denies that.

Summers thaw each pole's ice more than it is re-frozen


Not in the South Pole, as far as we can tell.

These are facts.


Not according to NSIDC, NASA, or NOAA.

Explaining away scientific fact is more akin to moral Creationists, not intelligent, objective and independent thinkers


A SECOND adhom attack. NICE

It's like claiming that a person of less than average intelligence is always smarter than Albert Einstein!


Now a second straw man. Good work.

Get an education, already!


And now a THIRD adhom for a hat-trick.

If you want to impress me, get quotes and provide references. You only gave one substantive remark and it was only half right. The rest was junk.
GSwift7
1 / 5 (2) Sep 20, 2011
You know, the above story reminds me a lot of this one:

http://www.thedai...ing-data

Back on topic though:

If the above mentioned climate model is capable of showing that the deep ocean can hide global warming for ten years, then does that change the long term predictions? Does it then re-release that heat and make the warming worse in the following decade? If so, then how do you rule out the possibility that a portion of recent warming wasnt due to that? I would say that they are raising more questions than answers here. They have inadvertently kicked a hornets' nest in regard to confidence in the very model they are using to support their claim.