From the National Center for Atmospheric Research/University Corporation for Atmospheric Research an explanation for Global Ocean Heat Content Is Still Flat.
Key point from the press release:
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
This new paper (which hasn’t been put online yet at NCC as of this writing, I’ll post a link as soon as I have one) from Trenberth is simply modeling, and modeling so far hasn’t done a very good job of accounting for the oceans:
I’d like to see some supporting observations, otherwise this is just speculation for something that Trenberth is doggedly trying to explain away. My question is; show me why some years the deep ocean doesn’t mask global warming. It’s not like that big heat sink was suddenly removed.
Deep oceans can mask global warming for decade-long periods
BOULDER — 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 computer simulations of global climate, 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 air temperatures 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 Climate Change. 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 greenhouse gases continued to climb during the 2000s, and satellite measurements 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 Niña
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. Global temperatures 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.
The University Corporation for Atmospheric Research manages the National Center for Atmospheric Research under sponsorship by the National Science Foundation. Any opinions, findings and conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
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h/t to WUWT reader Bradley Fikes
Trenberth is indeed a powerful tool.
Marlow Metcalf says:
September 19, 2011 at 12:07 am
People! You can do this!
Sorry, but we cannot make Kevin’s ludicrous claims look even vaguely plausible.
We would need a way to allow backscattered LWIR to slow the cooling of water that is free to evaporatively cool even though such IR radiation cannot even penetrate 10 microns through the 1mm skin layer. I am aware that a thin layer of LDPE plastic could do this, but there are not enough oil reserves on the planet to achieve this level of plastics production.
Then we would then need a way to get gigatonnes of warm water past a network of thousands ARGO buoy sensors without a gratuitous training montage with actor Sean Connery.
Further to this we would need a matter transporter to beam a Mediterranean Sea worth of water to the far side of the Moon to make sea level records compatible with decades of missing heat hidden in the ocean depths.
It is far easier to say that Kevin Trenberth should cease speculating about the ocean depths given his proven ability to get out of his depth on a wet pavement. Reverse the null hypothesis in the case of global warming? No one has forgotten, Kevin, nor will they ever.
“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.”
“Buried”? Is this a technical explanation for the energy transfer process?
How does Trenberth propose that the missing heat gets down past 700m of cooling upper ocean (I trust Loehle on this) to hide in Davy Jones locker? The man is thermodynamically challenged.
The climate clowns have dug a hole so deep for themselves that the missing heat fell in it with them.
@Marlow Metcalf,
“So far commenters have found three ways for warm water to go below cold water.”
The challenge is to find ways for warm water containing missing heat to go below cold water WITHOUT a detectable increase in sea level rise, due to thermal expansion of the oceans from the presence of the “missing heat”. Perhaps the missing heat isn’t on earth.
Konrad says:
September 19, 2011 at 2:00 am
Further to this we would need a matter transporter to beam a Mediterranean Sea worth of water to the far side of the Moon to make sea level records compatible with decades of missing heat hidden in the ocean depths.
Water is densest at 4C. The deeps below 3000m are colder than that. If they warmed 0.2C, sea level would fall.
Mike says:
September 18, 2011 at 12:27 pm
When it comes to heat what goes down must eventually come up.
About 850 years later. Some of the modern warming was from the medieval warm period perhaps?
Bill Illis says: Thanks for the link to the abstract of Meehl et al (2011). It’s unfortunate that the only thing not blocked by a paywall is the Supplementary Information:
http://www.nature.com/nclimate/journal/vaop/ncurrent/extref/nclimate1229-s1.pdf
What I’m worried about is the possibility that the oceans are masking global cooling for decades before it hits us up the side of the head.
@tallbloke,
“Water is densest at 4C. The deeps below 3000m are colder than that. If they warmed 0.2C, sea level would fall.”
You can’t hide missing heat without sea level rise that way, because salt water gets denser all the way down to its freezing point. So all increase in ocean heat, except for fresh water at the surface will increase sea level rise, unless sea water itself is “missing” due to increased retention of water on land, perhaps in ice caps, soil or behind dams..
Trenberth is so far out of his depth, he is surrounded by beasties with little fishing poles and lights on their heads
@richard Courtney:
2. The ability to suggest a possibility does NOT mean the possibility exists: e.g. some evidence is needed for the child, his rope, his bucket and his activity.
See thats where post normalism and science part ways. For the post normal thinker the assertion need only be ‘not neccessarilly not possible’ (in a modal logical sense) to be treated as assumed.
“I’m not sure why my zeroing the data in 2003 is so difficult for some people to accept. Hansen et al (2005) zeroed at 1993 to show how well the models recreated the rise in OHC from 1993 to 2003, but some bloggers attempt to criticize my graphs when I zero the data in 2003 to show how poorly the models match the data after that.”
Because the CAGW advocates are the good guys, so they can do whatever it takes to keep the gravy train on its tracks.
R Gates
I would appreciate your further views. I know that you answer questions put to you, and, I, for one, appreciate that you do.
We have previously exchanged comments (on other threads) upon the usefulness of models, and I am pleased to note that you accept that they are all wrong; we will have to beg to differ on how many models are encompassed in ‘some’ and how you define ‘useful.’
I fully share your view on the lack of qualitative data. Unfortunately, this lack of qualitative data extends to more than just ocean related data. The poor quality of the data no doubt partly explains our lack of understanding as to what is truly occurring in the real world. I hold the view that until you really understand what is going on in the real world, you cannot begin to create a worthwhile model. A flawed and incomplete understanding inevitably leads to a flawed and incomplete model.
We all know and accept that the oceans are great heat conveyors distributing heat all over the globe, including vertical transport in the ocean itself.
My question to you is this. If heat from the upper ocean is effectively transported to the mid and thence to the deep ocean, what would you expect to be the temperature of the mid and deep ocean, and why?
In answering this question, I would appreciate your views, obviously, in very general terms as to the order of magnitude of temperature being transported from the top ocean to the mid and deep ocean. If you wish to include the addition of geothermal heat, please feel free to add that in the mix of things.
I have in mind that if one assumes that say 0.0001 deg C per Century is transported from the top ocean to the deep, given that this process, no doubt, has been occurring ever since the planet formed oceans, say for a few billion years, one would (at least at first glance) expect the mid and deep ocean to be warmer than they are. There are no doubt many possible reasons as to why the mid and deep oceans are not warmer (including but not limited to the conclusion that the input energy into the oceans does not consist of Solar + DWLWIR, and/or if it does, then the DWLWIR is miniscule only), but I would be interested in hearing and considering your views on this and on the amount of heat being transported from top to bottom.
If one stops to consider the geological timescale involved and what this implies about the extent of energy/heat transport to the deep, it follows that we will never in our life time be able to witness and measure a change to the deep ocean temperature, or if, by some chance, we are able to measure a change in temperature, we will have one hell of a problem on our hands far exceeding the wildest nightmares of the most alarmist of the ‘warmista’,
I look forward to reading your further comments.
Makes sense to me. Cold water comes to surface, lowers temperatures, but absorb more heat.
I think Tisdale has said as much.
I’d look to patches on the ocean surface and where circulation patterns move water down.
tallbloke says:
September 19, 2011 at 2:49 am
Perhaps, but I’ve been scratching my head trying to figure out a mechanism in the ocean that would have an 850-year lag period and considering deep ocean current velocities, rollovers from density differences, etc., I can’t envision a mechanism centered in the oceans that would have an 850-year period.
Can you suggest such a long-cycle mechanism?
One reason he may be having trouble finding the heat is his assumption of the directionality of causation of warming and the THC slowdown. I’d be suprised if THC hasn’t accelerated since we seem to have shifted PDO phase and see more la Ninas.
With a cool ocean and still warm atmosphere, we probably also have more wind.
Marlow Metcalf says:
September 19, 2011 at 12:07 am
“People! You can do this!
So far commenters have found three ways for warm water to go below cold water. You can find more.”
The fact that warmer water can slip beneath cooler water is irrelevant to Trenberth’s claims for several reasons. Reason number one is that the warm water would be detected by the ARGO buoys and it has not been detected.
Reason number two is that Trenberth’s and friends’ paper contains no empirical research about this particular phenomenon. It would be wonderful if they would become inspired to be empirical researchers and actually do some studies of deep ocean temperatures, but that is less likely than each of us receiving a new supercomputer for Christmas.
Reason number three is that the claim being sold, namely that oceans are the repositories for the heat that should have accumulated over the last 13 years, is an example of a Cherry Picked Explanation. If there is some complicated ocean phenomenon of the sort Trenberth needs, it has been going on for eons, it is only now being discovered, and it is being treated as important for only one reason, namely, that it can be portrayed as explaining Trenberth’s missing heat. The scientific attitude toward such a phenomenon would be to treat is as important in its own right and to investigate it extensively rather than touching upon it just enough to explain the present difficulties in CAGW.
I would admit, that circulation of deep ocean heat over an 800-1000 year period was consistent with the emergence from the LIA.
I cannot think of a thing that Kev Trenberth has interpreted correctly, even remotely. In most disciplines such a poor track record would lead to simply being ignored; this happens to be one of those areas where someone could be wrong over 20, 30, 40 year periods and still get traction with the media (and amongst fellow misanthropes).
Has anyone made a serious study of the causes of misanthropy? Is the belief system singular to developed societies?
All together now: Models do not output evidence. Model outputs are not facts.
Repeat until you get it.
“Can you suggest such a long-cycle mechanism?”
The Thermohaline circulation is reputed to be anything between 1000 and 1500 years depending on who does the guessing. However there are multiple inputs and multiple outputs along the way and the ocean basis do not operate as one, they constantly interact with one another over time so various timings for a climate effect are possible.
Furthermore the pattern of energy going into and coming out of the THC would be in the form of a sine wave just like the longer term solar variations so we would see 500 to 750 years in one phase and 500 to 750 years in the opposite phase.
If we place the MWP at 1000 to 1300 AD then it could well be influencing CO2 levels and water temperatures today.
England has a long tradition of “the Village Idiot”.
Seemingly many of them are now employed by the UK Government.
In this archaic comedy clip from the 1970s, which has been viewed
over a million times, the “Monty Python” team explain that tradition.
It comes as no surprise that in the film the diplomas in idiocy are
handed out by none other than “East Anglia University”.
What did the “Python Team” know, and was this a warning of sorts ?
Salty ocean water is densest at about -1.0C although in practise this only occurs at the surface in the polar regions where the air temperature is coldest and directly under the sea ice.
Salty ocean water then starts to get less dense as the temperature declines below -1.0C (the starting point depends on the salinity – the Arctic ocean water starts to freeze and then floats becoming the least dense ocean water when temperatures get down to about -1.5C – Antarctica is a little lower than that).
The very deep ocean water next to Antarctica at about 4500 metres deep is the coldest densest deep ocean water on the planet at about -0.35C. Even in the ice ages, it would have been at about this temperature, but the extent of -0.35C water would have expanded, potentially even into the North Atlantic from Antarctica.
To me this comment by Will Nitschke is by far and away the most important point and which everyone else seems to have missed or skirted around.
“Isn’t the elephant in the room that, if this particular model is correct, that expected rates of warming are now much slower than originally predicted? Are we talking about 200 or 300 years to reach 2-4C of atmospheric warming, considering that the deep ocean can absorb much more heat than originally assumed and neutralize surface temperature warming for decades at a time? Does this mean we have much more time to deal with the problem of AGW than was originally assumed? If so, shouldn’t we be congratulating Trenberth for pointing us to arguments for why AGW now appears to be less urgent than was originally claimed?”
The fact is that whether there is any substance in the missing heat hypothesis or not, it does not let Trenberth off the hook in terms of his climate alarmism stance and how little time we have until Thermageddon.
Any heat absorbed into the deep ocean is essentially locked up for millennia. This means that it is not available to contribute to global warming until long after we have ceased to use fossil fuels or that they have run out. By the time the heat is transported back into the air, the CO2 in the atmosphere will have had time to regain natural equilibrium with the oceans (assuming it is not already in natural equilibrium now, which I believe it is) and will not be able to make any additional contribution to the greenhouse effect; that is if it does indeed make any significant contribution now. Additionally Will Nitschke’s point is that these temperature stasis intervals summed together must slow down the rate of global warming.
So I shall use a couple of very dirty words which I hope will get through moderation.
Your mechanism of stored heat in the lower ocean amounts to
NEGATIVE FEEDBACK Mr TRENBERTH and Meehl et al
There is no point in trying to worm out of the missing heat debate by claiming that it is stuck at the bottom of the ocean. You are only helping the sceptic cause by proposing an additional form of mitigating negative feedback.
And a comment to the editors at Nature Climate Change. Are you going to resign for permitting a very poorly constructed paper which failed to identify and mention the very important negative feedback implications of the proposed mechanism, with apologies to Mr Trenberth of course? And why did you approve these reviewers who failed to pick up such an omission?
This is probably a stupid question, but how did this heat by-pass the sensors on the way down? I mean it didn’t just appear there one day, it must have transitted the upper oceans to get there surely?