Deep Oceans Are Cooling Amidst A Sea of Modeling Uncertainty: New Research on Ocean Heat Content

Guest essay by Jim Steele, Director emeritus Sierra Nevada Field Campus, San Francisco State University and author of Landscapes & Cycles: An Environmentalist’s Journey to Climate Skepticism

Two of the world’s premiere ocean scientists from Harvard and MIT have addressed the data limitations that currently prevent the oceanographic community from resolving the differences among various estimates of changing ocean heat content (in print but available here).3 They point out where future data is most needed so these ambiguities do not persist into the next several decades of change. As a by-product of that analysis they 1) determined the deepest oceans are cooling, 2) estimated a much slower rate of ocean warming, 3) highlighted where the greatest uncertainties existed due to the ever changing locations of heating and cooling, and 4) specified concerns with previous methods used to construct changes in ocean heat content, such as Balmaseda and Trenberth’s re-analysis (see below).13 They concluded, “Direct determination of changes in oceanic heat content over the last 20 years are not in conflict with estimates of the radiative forcing, but the uncertainties remain too large to rationalize e.g., the apparent “pause” in warming.”

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Wunsch and Heimbach (2014) humbly admit that their “results differ in detail and in numerical values from other estimates, but the determining whether any are “correct” is probably not possible with the existing data sets.”

They estimate the changing states of the ocean by synthesizing diverse data sets using models developed by the consortium for Estimating the Circulation and Climate of the Ocean, ECCO. The ECCO “state estimates” have eliminated deficiencies of previous models and they claim, “unlike most “data assimilation” products, [ECCO] satisfies the model equations without any artificial sources or sinks or forces. The state estimate is from the free running, but adjusted, model and hence satisfies all of the governing model equations, including those for basic conservation of mass, heat, momentum, vorticity, etc. up to numerical accuracy.”

Their results (Figure 18. below) suggest a flattening or slight cooling in the upper 100 meters since 2004, in agreement with the -0.04 Watts/m2 cooling reported by Lyman (2014).6 The consensus of previous researchers has been that temperatures in the upper 300 meters have flattened or cooled since 2003,4 while Wunsch and Heimbach (2014) found the upper 700 meters still warmed up to 2009.

The deep layers contain twice as much heat as the upper 100 meters, and overall exhibit a clear cooling trend for the past 2 decades. Unlike the upper layers, which are dominated by the annual cycle of heating and cooling, they argue that deep ocean trends must be viewed as part of the ocean’s long term memory which is still responding to “meteorological forcing of decades to thousands of years ago”. If Balmaseda and Trenberth’s model of deep ocean warming was correct, any increase in ocean heat content must have occurred between 700 and 2000 meters, but the mechanisms that would warm that “middle layer” remains elusive.

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The detected cooling of the deepest oceans is quite remarkable given geothermal warming from the ocean floor. Wunsch and Heimbach (2014) note, “As with other extant estimates, the present state estimate does not yet account for the geothermal flux at the sea floor whose mean values (Pollack et al., 1993) are of order 0.1 W/m2,” which is small but “not negligible compared to any vertical heat transfer into the abyss.3 (A note of interest is an increase in heat from the ocean floor has recently been associated with increased basal melt of Antarctica’s Thwaites glacier. ) Since heated waters rise, I find it reasonable to assume that, at least in part, any heating of the “middle layers” likely comes from heat that was stored in the deepest ocean decades to thousands of years ago.

Wunsch and Heimbach (2014) emphasize the many uncertainties involved in attributing the cause of changes in the overall heat content concluding, “As with many climate-related records, the unanswerable question here is whether these changes are truly secular, and/or a response to anthropogenic forcing, or whether they are instead fragments of a general red noise behavior seen over durations much too short to depict the long time-scales of Fig. 6, 7, or the result of sampling and measurement biases, or changes in the temporal data density.”

Given those uncertainties, they concluded that much less heat is being added to the oceans compared to claims in previous studies (seen in the table below). It is interesting to note that compared to Hansen’s study that ended in 2003 before the observed warming pause, subsequent studies also suggest less heat is entering the oceans. Whether those declining trends are a result of improved methodologies, or due to a cooler sun, or both requires more observations.

 

 

Study Years Examined Watts/m2
9Hansen 2005 1993-2003 0.86 +/- 0.12
5Lyman 2010 1993-2008 0.64 +/- 0.11
10von Schuckmann 2011 2005-2010 0.54 +/- 0.1
3Wunsch 2014 1992-2011 0.2 +/- 0.1

 

No climate model had predicted the dramatically rising temperatures in the deep oceans calculated by the Balmaseda/Trenberth re-analysis,13 and oceanographers suggest such a sharp rise is more likely an artifact of shifting measuring systems. Indeed the unusual warming correlates with the switch to the Argo observing system. Wunsch and Heimbach (2013)2 wrote, “clear warnings have appeared in the literature—that spurious trends and values are artifacts of changing observation systems (see, e.g., Elliott and Gaffen, 1991; Marshall et al., 2002; Thompson et al., 2008)—the reanalyses are rarely used appropriately, meaning with the recognition that they are subject to large errors.3

More specifically Wunsch and Heimbach (2014) warned, “Data assimilation schemes running over decades are usually labeled “reanalyses.” Unfortunately, these cannot be used for heat or other budgeting purposes because of their violation of the fundamental conservation laws; see Wunsch and Heimbach (2013) for discussion of this important point. The problem necessitates close examination of claimed abyssal warming accuracies of 0.01 W/m2 based on such methods (e.g., Balmaseda et al., 2013).” 3

So who to believe?

Because ocean heat is stored asymmetrically and that heat is shifting 24/7, any limited sampling scheme will be riddled with large biases and uncertainties. In Figure 12 below Wunsch and Heimbach (2014) map the uneven densities of regionally stored heat. Apparently associated with its greater salinity, most of the central North Atlantic stores twice as much heat as any part of the Pacific and Indian Oceans. Regions where there are steep heat gradients require a greater sampling effort to avoid misleading results. They warned, “The relatively large heat content of the Atlantic Ocean could, if redistributed, produce large changes elsewhere in the system and which, if not uniformly observed, show artificial changes in the global average.” 3

 

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Furthermore, due to the constant time-varying heat transport, regions of warming are usually compensated by regions of cooling as illustrated in their Figure 15. It offers a wonderful visualization of the current state of those natural ocean oscillations by comparing changes in heat content between1992 and 2011. Those patterns of heat re-distributions evolve enormous amounts of heat and that make detection of changes in heat content that are many magnitudes smaller extremely difficult. Again any uneven sampling regime in time or space, would result in “artificial changes in the global average”.

Figure 15 shows the most recent effects of La Nina and the negative Pacific Decadal Oscillation. The eastern Pacific has cooled, while simultaneously the intensifying trade winds have swept more warm water into the western Pacific causing it to warm. Likewise heat stored in the mid‑Atlantic has likely been transported northward as that region has cooled while simultaneously the sub‑polar seas have warmed. This northward change in heat content is in agreement with earlier discussions about cycles of warm water intrusions that effect Arctic sea ice, confounded climate models of the Arctic and controls the distribution of marine organisms.

Most interesting is the observed cooling throughout the upper 700 meters of the Arctic. There have been 2 competing explanations for the unusually warm Arctic air temperature that heavily weights the global average. CO2 driven hypotheses argue global warming has reduced polar sea ice that previously reflected sunlight, and now the exposed dark waters are absorbing more heat and raising water and air temperatures. But clearly a cooling upper Arctic Ocean suggests any absorbed heat is insignificant. Despite greater inflows of warm Atlantic water, declining heat content of the upper 700 meters supports the competing hypothesis that warmer Arctic air temperatures are, at least in part, the result of increased ventilation of heat that was previously trapped by a thick insulating ice cover.7 That second hypothesis is also in agreement with extensive observations that Arctic air temperatures had been cooling in the 80s and 90s. Warming occurred after subfreezing winds, re‑directed by the Arctic Oscillation, drove thick multi-year ice out from the Arctic.11

Regional cooling is also detected along the storm track from the Caribbean and along eastern USA. This evidence contradicts speculation that hurricanes in the Atlantic will or have become more severe due to increasing ocean temperatures. This also confirms earlier analyses of blogger Bob Tisdale and others that Superstorm Sandy was not caused by warmer oceans.

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In order to support their contention that the deep ocean has been dramatically absorbing heat, Balmaseda/Trenberth must provide a mechanism and the regional observations where heat has been carried from the surface to those depths. But few are to be found. Warming at great depths and simultaneous cooling of the surface is antithetical to climate models predictions. Models had predicted global warming would store heat first in the upper layer and stratify that layer. Diffusion would require hundreds to thousands of years, so it is not the mechanism. Trenberth, Rahmstorf, and others have argued the winds could drive heat below the surface. Indeed winds can drive heat downward in a layer that oceanographers call the “mixed-layer,” but the depth where wind mixing occurs is restricted to a layer roughly 10-200 meters thick over most of the tropical and mid-latitude belts. And those depths have been cooling slightly.

The only other possible mechanism that could reasonably explain heat transfer to the deep ocean was that the winds could tilt the thermocline. The thermocline delineates a rapid transition between the ocean’s warm upper layer and cold lower layer. As illustrated above in Figure 15, during a La Nina warm waters pile up in the western Pacific and deepens the thermocline. But the tilting Pacific thermocline typically does not dip below the 700 meters, if ever.8

Unfortunately the analysis by Wunsch and Heimbach (2014) does not report on changes in the layer between 700 meters and 2000 meters. However based on changes in heat content below 2000 meters (their Figure 16 below), deeper layers of the Pacific are practically devoid of any deep warming.

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The one region transporting the greatest amount of heat into the deep oceans is the ice forming regions around Antarctica, especially the eastern Weddell Sea where annually sea ice has been expanding.12 Unlike the Arctic, the Antarctic is relatively insulated from intruding subtropical waters (discussed here) so any deep warming is mostly from heat descending from above with a small contribution from geothermal.

Counter‑intuitively greater sea ice production can deliver relatively warmer subsurface water to the ocean abyss. When oceans freeze, the salt is ejected to form a dense brine with a temperature that always hovers at the freezing point. Typically this unmodified water is called shelf water. Dense shelf water readily sinks to the bottom of the polar seas. However in transit to the bottom, shelf water must pass through layers of variously modified Warm Deep Water or Antarctic Circumpolar Water. Turbulent mixing also entrains some of the warmer water down to the abyss. Warm Deep Water typically comprises 62% of the mixed water that finally reaches the bottom. Any altered dynamic (such as increasing sea ice production, or circulation effects that entrain a greater proportion of Warm Deep Water), can redistribute more heat to the abyss.14. Due to the Antarctic Oscillation the warmer waters carried by the Antarctic Circumpolar Current have been observed to undulate southward bringing those waters closer to ice forming regions. Shelf waters have generally cooled and there has been no detectable warming of the Warm Deep Water core, so this region’s deep ocean warming is likely just re-distributing heat and not adding to the ocean heat content.

So it remains unclear if and how Trenberth’s “missing heat” has sunk to the deep ocean. The depiction of a dramatic rise in deep ocean heat is highly questionable, even though alarmists have flaunted it as proof of Co2’s power. As Dr. Wunsch had warned earlier, “Convenient assumptions should not be turned prematurely into ‘facts,’ nor uncertainties and ambiguities suppressed.” … “Anyone can write a model: the challenge is to demonstrate its accuracy and precision… Otherwise, the scientific debate is controlled by the most articulate, colorful, or adamant players.” 1

 

To reiterate, “the uncertainties remain too large to rationalize e.g., the apparent “pause” in warming.”

==================================

Literature Cited

 

1. C. Wunsch, 2007. The Past and Future Ocean Circulation from a Contemporary Perspective, in AGU Monograph, 173, A. Schmittner, J. Chiang and S. Hemming, Eds., 53-74

2. Wunsch, C. and P. Heimbach (2013) Dynamically and Kinematically Consistent Global Ocean Circulation and Ice State Estimates. In Ocean Circulation and Climate, Vol. 103. http://dx.doi.org/10.1016/B978-0-12-391851-2.00021-0

3. Wunsch, C., and P. Heimbach, (2014) Bidecadal Thermal Changes in the Abyssal Ocean, J. Phys. Oceanogr., http://dx.doi.org/10.1175/JPO-D-13-096.1

4. Xue,Y., et al., (2012) A Comparative Analysis of Upper-Ocean Heat Content Variability from an Ensemble of Operational Ocean Reanalyses. Journal of Climate, vol 25, 6905-6929.

5. Lyman, J. et al, (2010) Robust warming of the global upper ocean. Nature, vol. 465,334-

337.

6. Lyman, J. and G. Johnson (2014) Estimating Global Ocean Heat Content Changes in the Upper 1800m since 1950 and the Influence of Climatology Choice*. Journal of Climate, vol 27.

7. Rigor, I.G., J.M. Wallace, and R.L. Colony (2002), Response of Sea Ice to the Arctic Oscillation, J. Climate, v. 15, no. 18, pp. 2648 – 2668.

8. Zhang, R. et al. (2007) Decadal change in the relationship between the oceanic entrainment temperature and thermocline depth in the far western tropical Pacific. Geophysical Research Letters, Vol. 34.

9. Hansen, J., and others, 2005: Earth’s energy imbalance: confirrmation and implications. Science, vol. 308, 1431-1435.

10. von Schuckmann, K., and P.-Y. Le Traon, 2011: How well can we derive Global Ocean Indicators

from Argo data?, Ocean Sci., 7, 783-791, doi:10.5194/os-7-783-2011.

11. Kahl, J., et al., (1993) Absence of evidence for greenhouse warming over the Arctic Ocean in the past 40 years. Nature, vol. 361, p. 335‑337, doi:10.1038/361335a0

12. Parkinson, C. and D. Cavalieri (2012) Antarctic sea ice variability and trends, 1979–2010. The Cryosphere, vol. 6, 871–880.

13. Balmaseda, M. A., K. E. Trenberth, and E. Kallen, 2013: Distinctive climate signals in reanalysis of global ocean heat content. Geophysical Research Letters, 40, 1754-1759.

14. Azaneau, M. et al. (2013) Trends in the deep Southern Ocean (1958–2010): Implications for Antarctic Bottom Water properties and volume export. Journal Of Geophysical Research: Oceans, Vol. 118

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DontGetOutMuch

“So it remains unclear if and how Trenberth’s “missing heat” has sunk to the deep ocean. ”
Personally, I think he is hiding it in his pants.

Thanks, Jim.

Reblogged this on Centinel2012 and commented:
Good work showing that we still don’t know enough about what is going on in the oceans to make drastic changes in the way that be live.

Rob Dawg

20 years of alarmist “worse than we thought” bleatings followed by 20 years of nowhere near as even the least apocalyptic prognostications supported by science.

Trenberth’s ‘deep ocean heat’ was always nonsense. Heat rises. That’s the Law.

Bill Illis

This is a very significant paper. The deep oceans are cooling. There is NO net energy imbalance on planet Earth. The full oceans have actually been losing energy since mid-2009.
There have only been two other studies looking at deep ocean heat content, one dealing with a small area next to Antarctica (slight warming) and one for most of the North Atlantic (slight cooling). This study now covers basically all of the deep oceans.
This will re-write the climate books.
How does the deep ocean cool while the upper ocean is warming? It would come from the deep water formation (bottom water sinking) next to and under the sea ice. It can completely skip the upper ocean numbers.

Latitude

uncertainties = we dunno
Sorta backaswards way of looking at it…..the deeper you go, the colder it gets
If the deep warms a tad..it doesn’t transfer heat up….it just doesn’t buffer as much heat down

I have spent some time collecting and collating tectonic data. There is reasonable correlation (positive in N. Atlantic and N. Pacific, negative in the sub-equatorial Pacific) with the local climate indices.
Is there any and what a mechanism might be (vertical mixing, temporary break or an interference the termohaline layers integrity, or something else) I have no idea.
Impression is that the most climate ‘scientists’ and many other minor players in the field have vested interests or ‘pet hypothesis’, which they are prepared to guard with whatever it takes, as it is often witnessed on the various climate blogs.

actually, it is the CO2 who dunnit
CO2(gas) + water (liquid) + cold => HCO3- + H3O+
More CO2 (produced by man and nature ) and more cold (made by nature) makes the equilibrium going to the right.Hence the upper oceans are “absorbing” some of the global cooling.

Robert Austin

Knowledge of ocean heat content prior to Argo is highly suspect.Charts like the Balmesada one are manufactured from a position of deep faith and confirmation bias. While the best metric of global temperature change would certainly be ocean heat content, there is insufficient data presently to reach any conclusions.

phlogiston

Just arrived at a Finnish hotel for a business trip on Oulu, sat in a sauna then jumped in cold water. Deeply refreshing. And now this – intellectual refreshment to a similar degree. What a day.
This could easily be the most important climate post (that I have seen) this year on WUWT.
I have been drawn increasingly to the conclusion that the whole ocean, all the way down to the bottom, has to be the 99% driver of climate trends on decadal and longer timescales. Think of all the heat in the ocean – an almost unimaginable amount, something like 99% of the atmosphere plus ocean heat.
So the authors are dead right to point to conservation of all this heat, and to smack down trivial and nonsensical warmist fansasies posing as scientific studies claiming impossible ocean warming. With the atmosphere accounting for such a tiny fraction of climate heat, it makes perfect sense to treat the oceans over timescales of years to decades as an ADIABATIC system, if one part warms another must cool. For it to be otherwise needs an impossibly large heat flux that would be impossible not to notice.
So the supposed apocalyptic warming over the last half century has been nothing more than oceanic housekeeping or rearrangement, shifting of heat from the lowest depths toward the surface. This could be brought about on a global scale by (1) changed pattern of cold deep water formation at the principal sites such as the Norwegian sea and around Antarctica, and (2) changed pattern of deep upwelling.
The authors are also dead right to point to how much is not known – in contrast to the bragging all-knowing arrogant warmists whose “mouths claim the heavens and tongues claim the earth”.
But at least we know where to look. Down, not up.

Merrick

So, as I’ve commented before, water is densest at 4C. Above 4C water expands. That’s what warmists think is driving sea level rise along with the essentially non-existent land ice losses. Below 4C water expands, then expands a lot when it goes through the transition from liquid to solid. A quick look at Figure 2 from the paper shows that everything below 400m is below 4C. So the deep ocean cooling is causing the ocean to expand. The sea level is rising because of GLOBAL COOLING.

Bruce Cobb

If only they could get rid of the “Modern Pause” (MP) the same way they got rid of the MWP.
Oh wait, they didn’t.
Still, they manage to put a brave face on it: “changes in oceanic heat content over the last 20 years are not in conflict with estimates of the radiative forcing”…
Sure, just keep telling yourselves that.

Kurt in Switzerland

Robert Austin (July 21 @ 10:40 AM)
Spot on!
Further comment on the matter is a waste of space.

Merrick says
the sea level is rising because of GLOBAL COOLING.
Henry says
true
I doubt that many people realize this
but it is the reason why water pipes burst when they freeze up
to prove that is globally cooling
http://blogs.24.com/henryp/2013/02/21/henrys-pool-tables-on-global-warmingcooling/

phlogiston

Merrick says:
July 21, 2014 at 10:43 am
So, as I’ve commented before, water is densest at 4C. Above 4C water expands. That’s what warmists think is driving sea level rise along with the essentially non-existent land ice losses. Below 4C water expands, then expands a lot when it goes through the transition from liquid to solid. A quick look at Figure 2 from the paper shows that everything below 400m is below 4C. So the deep ocean cooling is causing the ocean to expand. The sea level is rising because of GLOBAL COOLING.
Hold your horses – saline seawater has its maximum density at a lower temperature of 0-2C, while for fresh water it is 4C.
I seem to remember being told in university oceanography classes that the huge pressure of the deepest ocean water keeps it at the temperature of minimum volume – too much energy would be needed to raise the whole water column. This raises some interesting thermodynamic questions. Such as what happens to the warm water that Jim Steele explains is entrained downwards with cold downwelling. My guess would be that it never makes it to the bottom – to displace denser water would require the lifting of the water column several miles deep.

Bob Bolder

Anthony
i hate to say this, but i think you are going lose all of your followers. Without the AGW crowd who are we going to have to argue with. I am afraid that i will have to move to some boring political site or something to find someone to argue with.
Next time don’t be so good a your job maybe the competition will be able to hang in there a little longer.
I give you another year and half before you have to find another bogus crisis to expose but take your time milk it a little next time.

Jim Steele,
An outstanding article.
John

Taphonomic

Trenberth’s “missing heat” is doing such a good job of hiding that it’s masquerading as cooling.

Mike Jowsey

Here’s the link to the paper in pdf form (article link above goes to Wunsch home page): http://ocean.mit.edu/~cwunsch/papersonline/heatcontentchange_26dec2013_ph.pdf

AlexS

“the uncertainties remain too large to rationalize”
We don’t even know fully what are the uncertainties.

john robertson

So in Climatology; The more things change, the more they stay the same.
What next, climatology will discover that approx 70% of earth is covered by water?

Babette

” Those patterns of heat re-distributions evolve enormous amounts of heat and that make detection of changes in heat content that are many magnitudes smaller extremely difficult.”
s/b(?) ” Those patterns of heat re-distributions INvolve enormous amounts of heat and that make detection of changes in heat content that are many magnitudes smaller extremely difficult.”

Gary Hladik

So Trenberth’s “missing heat” is still missing? Back on the milk carton it goes!

Gary Hladik says
So Trenberth’s “missing heat” is still missing?
Henry says
no
I found it.
it went to space
actually

pokerguy

I’ve been somewhat depressed over the last 12 months or so, as nothing of real significance has come along in that time. Or if it has, I wasn’t able to recognize it as such. All the excitement around the papers positing lower atmospheric sensitivity had long since dissipated. Finally! Something that strikes me…and many others…as a major advance….or rather a major humbling with its recognition of how much we really don’t know.
Another blow to the disingenuous warmists. One of these days, some bright young MSM journalist is going to come along and realize this CAGW nonsense is the greatest scientific mistake ( to be kind) in modern history. It’s a great story waiting only to be written.

Eugene WR Gallun

I posted this here a couple years ago but this seems an appropriate time to re-post it.
TRENBERTH LOSES HIS STRAWBERRIES
(See the courtroom scene from the Caine Mutiny)
As greenhouse gases still accrete
This captain of the climate wars
Is searching for the missing heat
That he believes the ocean stores
He’ll prove to all humanity
That danger in the deep resides
The Kraken that he knows to be
That Davy Jones’s locker hides
The soul’s more heavy than we think
A truth that everyone must face
And to what depths a soul may sink
Oh! To what dark and dismal place!
Does Captain Trenberth understand
That data offers no appeal?
He tumbles in his restless hand
Three clacking balls of stainless steel
MY GEOMETRIC LOGIC PROVES
HEAT TELEPORTS FROM PLACE TO PLACE
FROM SKIES INTO THE DEEPS IT MOVES
AND IN BETWEEN IT LEAVES NO TRACE!
When silent faces stare at you
Its always best to shut your jaw
But Trenberth is without a clue
As he believes they stare in awe
Eugene WR Gallun

Merrick

phlogiston says:
July 21, 2014 at 10:50 am
Hold your horses – saline seawater has its maximum density at a lower temperature of 0-2C, while for fresh water it is 4C.
Hold your own horses. See figure 3. Greater than 95% of the ocean’s volume is below 0C and greater than 90% is below -2C. A proper treatment requires taking the tremendous pressures into account, as you suggest, but a colder ocean overall (not just the surface) is a BIGGER ocean, and a warmer ocean overall (not just the surface) is a SMALLER ocean.
If the deep ocean temperature was static and the upper ocean warmed then the overall sea level would rise due to warming. If the deep ocean were warming (a la Trenberth) the contraction of that volume would so overwhelm anything going on at the surface that ocean expansion would be absolutely impossible.
In response to your comment about the deep sea being unable (or at least highly unwilling) to expand due to all the pressure (which is really nothing, last time I checked the gravitational force constant which gives rise to pressure is still many many orders of magnitude lower than the electrical force constant which directs the water to expand or contract according to temperature and salinity. And, in this case, if Trenberth were right the deep ocean would have an additional entropic benefit to warming because it could allow itself to contract with warming.
Sorry. This dog don’t hunt.

JohnB

@Everyone who thinks they have hit on the abject stupidity of all climate scientists who are ignorant of the fact that water is at its densest at 4 °C. Geez, don’t those guys know anything? Well… That is only true of *fresh* water. Sea water is at its densest just above its freezing point. Hence, “The oceans’ cold water near the freezing point continues to sink.”
http://en.wikipedia.org/wiki/Properties_of_water

Merrick

Sorry – mistyped. Half of the ocean is below -2C.

Alx

Just a thought, but maybe before trying to build models that forecast or predict global climate it might be advantageous to better understand how global climate works, including not only with ocean processes but with all the other various and diverse eco-processes across the planet. I guess that goal is incredibly difficult and not as sexy as being the next Nostradamus.

Merrick

Sorry again. Totally misread that graph!

Very interesting! The bottom line is “insufficient data”, but the openness that it is presented with is refreshing.

Old'un

Here’s another admission of something we can’t really be sure about. The list is steadily getting longer!

Eugene WR Gallun says:
July 21, 2014 at 11:55 am
——
Nice!

phlogiston

Merrick says:
July 21, 2014 at 11:55 am
phlogiston says:
July 21, 2014 at 10:50 am
Hold your horses – saline seawater has its maximum density at a lower temperature of 0-2C, while for fresh water it is 4C.
Hold your own horses. See figure 3. Greater than 95% of the ocean’s volume is below 0C and greater than 90% is below -2C. A proper treatment requires taking the tremendous pressures into account, as you suggest, but a colder ocean overall (not just the surface) is a BIGGER ocean, and a warmer ocean overall (not just the surface) is a SMALLER ocean.
You misread figure 3 of the Wunsch paper. Temperature is on the right, not left. The left color scale is a logarithmic scale of relative volume.
Thus most bottom water from bottom up to ~2000m is around 0-3C.
The maximum density of seawater is at -3.7 C although this is attained only by supercooling, normally it freezes at -2C. See this page – and the seawater density calculator near the bottom of the page:
http://www.es.flinders.edu.au/~mattom/IntroOc/lecture03.html
Thus with respect I dont think that expansion of seawater due to cooling (rather than warming) is a possible factor causing sea level rise – you would be talking about a huge amount of highly supercooled seawater below -4C. Wunsch’s figure 3 shows such water is not to be found.
Nonetheless I dont exclude that the oceans are cooling. I think the important conclusion from the paper discussed by Jim Steele is that (1) surface layer apparent ocean warming is borrowed heat from lower down so no overall warming, and (2) we dont have enough knowledge to say for sure if there is an overall trend of cooling/warming in the ocean as a whole – but warmist claims of signifcant warming are almost certainly dead wrong.

phlogiston

@Merrick
Sorry – fig 3 – temperature is on the left, not right.

Doug Proctor

Why would you have shallow and deep analyzes and not middle? Same data source, right?
I can’t get a post 2004 decline from the first, color graph. Why?
The northern Atlantic hot region: historically stable, existed the same prior to 1975?
The growing divergence shallow, middle and total energy content: just temperature change or temp plus salinity plus increased data control? Unstable OR a reversion to how things used to be, previous heat at depth was released earlier, causing the recent atmospheric warming?

M Courtney

I would expect the sea level to be rising because the ice age is over and the glaciers are net shrinking as they have been for millennia.
Indeed, the fact the rate of sea level rise is reasonably constant implies to me that we don’t need fancy thermodynamics to explain it.

RayG

The U.S. Navy’s nuclear-powered submarine fleet regularly traverses the Earth’s oceans often at a considerable depth. I would be surprised if the subs don’t sample the temperature of the waters through which they pass on a very regular basis. This is necessary for them to understand the limitations of their sonar at any particular time. While their lat-long positions may only be approximations, this data could be of significant value in improving our understanding of the ocean’s heat content.

@RayG – the maximum effective depth (at least published) of submarines is about 1000 meters (some can go deeper, but they are more exploratory). So that is only half of the “2000” meters that Trenberth thinks the heat is hiding under.

RayG;
I would be surprised if the subs don’t sample the temperature of the waters through which they pass on a very regular basis.
>>>>>>>>>>>>>>>>.
I’d be even more surprised if the US Navy would tell you where their subs have been and when they were there 😉

@DavidmHoffer

I’d be even more surprised if the US Navy would tell you where their subs have been and when they were there 😉

Yea, that too!

John Bills

IPCC AR5 TS.6 Key Uncertainties
This final section of the Technical Summary provides readers with a
short overview of key uncertainties in the understanding of the climate
system and the ability to project changes in response to anthropogenic
influences. The overview is not comprehensive and does not describe in
detail the basis for these findings.
OHC:
• Different global estimates of sub-surface ocean temperatures have
variations at different times and for different periods, suggesting
that sub-decadal variability in the temperature and upper heat
content (0 to to 700 m) is still poorly characterized in the historical
record.
• Below ocean depths of 700 m the sampling in space and time is
too sparse to produce annual global ocean temperature and heat
content estimates prior to 2005.
• Observational coverage of the ocean deeper than 2000 m is still
limited and hampers more robust estimates of changes in global
ocean heat content and carbon content. This also limits the quantification
of the contribution of deep ocean warming to sea level
rise.

Wunsch and Heimbach (2014) humbly admit that their “results differ in detail and in numerical values from other estimates, but the determining whether any are “correct” is probably not possible with the existing data sets.”
C’mon guys, just make up the data and average the models to get a “best” result and then claim it matches observations.
It’s not like you would be the first to do that.
Oh, and then submit it to Nature to be published.
/sarc

spettro

All this heat over all this cold… At least the study authors acknowledge with the quotation marks that the pause is a claim, and further that it is simply apparent, not real. Hence does not require any rationalization. Thanks for clearing *that* up!

SasjaL

“Because ocean heat is stored asymmetrically and that heat is shifting 24/7, any limited sampling scheme will be riddled with large biases and uncertainties.”
Obviously …
( my emphasis )

daveandrews723

I’m not a scientist, but simple logic would seem to dictate that any scientist who claims to know what controls the earth’s climate has to be one arrogant person. It is obviously a complex, massive system with all sorts of factors involved. To put all this weight on CO2 increase as reason for panic about “climate change and global warming” has always seemed beyond the pale to me.

M Courtney

I’ve read and read this and I can’t accept the title, “Deep Oceans Are Cooling Amidst A Sea of Modelling Uncertainty: New Research on Ocean Heat Content”.
It seems to me that we just don’t know if it’s cooling, warming or circulating round and round and round.
And we certainly don’t know if it’s changed.
Is the meaningless the point?

M Courtney
– I hear you. The longer this idiocy goes on, the more convinced I am that we’re all characters trapped in a Kafka novel.

jones

Is it hiding even deeper down?

Duster

RayG says:
July 21, 2014 at 1:01 pm
The U.S. Navy’s nuclear-powered submarine fleet regularly traverses the Earth’s oceans often at a considerable depth. …

Not at those depths. The Virginia class subs have a max depth of “greater than 800 feet,” purportedly as much 1,000 to 1,600 feet according to guesses, so, possibly somewhat more than 300 meters max. The zone of interest here is from two to more than ten times that what fleet submarine is likely to be able to reach safely.