Maybe they've found Trenberth's missing heat

NOAA: Scientists Find 20 Years of Deep Water Warming Leading to Sea Level Rise

Sea-level rise has the potential to reshape the coastal environment.

Sea-level rise has the potential to reshape the coastal environment. Credit: NOAA)

Scientists analyzing measurements taken in the deep ocean around the globe over the past two decades find a warming trend that contributes to sea level rise, especially around Antarctica.

Greenhouse gases in the atmosphere, such as carbon dioxide, cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy has gone into the ocean, warming it in the process.

“Previous studies have shown that the upper ocean is warming, but our analysis determines how much additional heat the deep ocean is storing from warming observed all the way to the ocean floor,” said Sarah Purkey, an oceanographer at the University of Washington and lead author of the study.

This study shows that the deep ocean – below about 3,300 feet – is taking up about 16 percent of what the upper ocean is absorbing. The authors note that there are several possible causes for this deep warming: a shift in Southern Ocean winds, a change in the density of what is called Antarctic Bottom Water, or how quickly that bottom water is formed near the Antarctic, where it sinks to fill the deepest, coldest portions of the ocean around much of the globe.

The scientists found the strongest deep warming around Antarctica, weakening with distance from its source as it spreads around the globe. While the temperature increases are small (about 0.03°C per decade in the deep Southern Ocean, less elsewhere), the large volume of the ocean over which they are found and the high capacity of water to absorb heat means that this warming accounts for a huge amount of energy storage. If this deep ocean heating were going into the atmosphere instead – a physical impossibility – it would be warming at a rate of about 3°C (over 5°F) per decade.

“A warming Earth causes sea level rise in two ways,” said Gregory Johnson, a NOAA oceanographer at the Pacific Marine Environmental Laboratory in Seattle, and the study’s co-author. “The warming heats the ocean, causing it to expand, and melts continental ice, adding water to the ocean. The expansion and added water both cause the sea to encroach on the land.”

Sea level has been rising at around 3 mm (1/8 of a inch) per year on average since 1993, with about half of that caused by ocean thermal expansion and the other half because of additional water added to the ocean, mostly from melting continental ice. Purkey and Johnson note that deep warming of the Southern Ocean accounts for about 1.2 mm (about 1/20th of an inch) per year of the sea level rise around Antarctica in the past few decades.

The highly accurate deep-ocean temperature observations used in this study come from ship-based instruments that measure conductivity through salinity, temperature and depth. These measurements were taken on a series of hydrographic surveys of the global ocean in the 1990s through the World Ocean Circulation Experiment and in the 2000s in support of the Climate Variability program. These surveys are now coordinated by the international Global Ship-based Hydrographic Investigations Program.

The study, “Warming of Global Abyssal and Deep Southern Ocean Waters between the 1990s and 2000s: Contributions to Global Heat and Sea Level Rise Budgets,” authored by Sarah G. Purkey and Gregory C. Johnson, will be published in an upcoming edition of the Journal of Climate.

NOAA’s mission is to understand and predict changes in the Earth’s environment, from the depths of the ocean to the surface of the sun, and to conserve and manage our coastal and marine resources. Find us on Facebook.

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Here is the abstract:

Journal of Climate 2010 ; e-View
doi: 10.1175/2010JCLI3682.1
Warming of Global Abyssal and Deep Southern Ocean Waters Between the 1990s and 2000s: Contributions to Global Heat and Sea Level Rise Budgets*
Sarah G. Purkey1,2 and Gregory C. Johnson2,1 1 School of Oceanography, University of Washington, Seattle WA 98195, USA

2 NOAA/Pacific Marine Environmental Laboratory, Seattle WA 98115, USA

Abstract

We quantify abyssal global and deep Southern Ocean temperature trends between the 1990s and 2000s to assess the role of recent warming of these regions in global heat and sea level budgets. We compute warming rates with uncertainties along 28 full-depth, high-quality, hydrographic sections that have been occupied two or more times between 1980 and 2010. We divide the global ocean into 32 basins defined by the topography and climatological ocean bottom temperatures and estimate temperature trends in the 24 sampled basins. The three southernmost basins show a strong statistically significant abyssal warming trend, with that warming signal weakening to the north in the central Pacific, western Atlantic, and eastern Indian Oceans. Eastern Atlantic and western Indian Ocean basins show statistically insignificant abyssal cooling trends. Excepting the Arctic Ocean and Nordic seas, the rate of abyssal (below 4000 m) global ocean heat content change in the 1990s and 2000s is equivalent to a heat flux of 0.027 (±0.009) W m−2 applied over the entire surface of the Earth. Deep (1000–4000 m) warming south of the Sub-Antarctic Front of the Antarctic Circumpolar Current adds 0.068 (±0.062) W m−2. The abyssal warming produces a 0.053 (±0.017) mm yr−1 increase in global average sea level and the deep warming south of the Sub-Antarctic Front adds another 0.093 (±0.081) mm yr−1. Thus warming in these regions, ventilated primarily by Antarctic Bottom Water, accounts for a statistically significant fraction of the present global energy and sea level budgets.

Received: February 16, 2010; Revised: July 28, 2010; Revised: August 18, 2010

*Pacific Marine Environmental Laboratory Contribution Number 3524.

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Mike D in Alberta

I would feel a little more comfortable with the trend numbers if there were +/- values associated with them to show the accuracy of the original readings. +0.03K +/- 1.0? +/- 0.1? +/- 0.000001? I suspect the second case is likely the closest to the “truth”. I also doubt that there are sufficient stations for a good representation, but at least this is a step up because it doesn’t state “we modelled the deep-oceanic temperatures and our models gave us the following data…”
Baby steps, Baby steps.

The abyssal warming produces a 0.053 (±0.017) mm yr−1 increase in global average sea level and the deep warming south of the Sub-Antarctic Front adds another 0.093 (±0.081) mm yr−1. Thus warming in these regions, ventilated primarily by Antarctic Bottom Water, accounts for a statistically significant fraction of the present global energy and sea level budgets.

Is 0.053 mm per year, or even 0.093 mm per year a “a statistically significant fraction” of anything that I should be concerned about? I can’t quite see it…..

Garry

CAGW Alert: The Western world is boiling all of the plankton in the hydrosphere!

Ray

Since when warm water is denser than cold water? Looks like they never did the hot/cold colored water experiment… only NOAA can make changes to the physics of things and understand why things work in reverse in their world!!!

Julian in Wales

So this study started in 1990s and has been running for less than 20 years? We all agree the 1980 -2000 was a warmer period than say the 1950 – 60s, does anyone know if the water was cooling or warming during these cooler decades?
The sea levels are going up by 1.2mm per year, that is 30 cms per century, hardly liklely to flood London or even the Tuvalu Islands in the liftimes of our grandchildren’s grandchildren, or am I missing something? It certainly leaves us time to imporve our sea walls whilst more studies check the science is correct and validate the causes.

Julian in Wales

sorry should have written 3.mm per year since 1993

Chris H

Have they put the cart before the horse? They attribute the deep ocean warming to rising atmospheric CO2. Is it not just as likely that something else caused the deep ocean warming and the CO2 rise simply represents the deep ocean de-gassing?

The post reads, “Greenhouse gases in the atmosphere, such as carbon dioxide, cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy has gone into the ocean, warming it in the process.”
Contrary to this, the Ocean Heat Content (OHC) for the top 700 meters of the oceans shows little to no signs of anthropogenic forcing. You simply need to divide the oceans into smaller subsets to see this. The majority of the rises in most of the ocean basins are tied to the significant La Niña events of 1973/74/75/76, and 1995/96, and 1998/99/00/01. Refer to:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
The North Atlantic appears to be impacted by ENSO, the North Atlantic Oscillation (NAO), and AMOC. The surface area of the North Atlantic represents only 15% of the global oceans but it accounts for more than 30% of the rise in OHC since 1955. It is also where most of the drop since 2005 has been occurring.
http://bobtisdale.blogspot.com/2009/10/north-atlantic-ocean-heat-content-0-700.html
And the North Pacific OHC dropped from the late 1960s until the late 1980s, then suddenly rose. The rise coincides with a shift in sea level pressure in the North Pacific:
http://bobtisdale.blogspot.com/2009/12/north-pacific-ocean-heat-content-shift.html

Chuck

Thank you Mr. Watts. It is kind of interesting.
3rd warming period of the inter-glacial period we are.
Not much concern here at the beach at the moment. I see their point though. I found in the past I have to move the beer cooler from time to time as the sea levels come up.
Thanks for the warning. It could have been a close one.

zzz

It boggles the imagination to think that oceanographers can compare temperature measurements made decades apart to within several hundredth’s of a degree C. Remember, these measurements were not made leisurely, with lots of time inside a scientific laboratory using carefully calibrated instruments, but rather thousands of feet down below the ocean surface using thermometers carried remotely by a robot submarine or dangling from a cable dropped over the side of a ship. Amazing!

So far the warming has been far below the 6 ° C rate the alarmists want to use for a doubling of CO2. Since we have had 1/3 of a doubling of CO2 we should have had more than 2 ° C warming we haven’t had this. [.7 ° C is the accepted value and less than ½ of that is from CO2 in the best case.]
To get around this alarmists have speculated that the ”missing heat” is stored in the oceans ! The problem is that since 2005 both atmosphere and the ocean have been cooling.
http://www.nodc.noaa.gov/OC5/3M_HEAT_CONTENT/
Some have SPECULATED that the missing heat may be in the deep parts of the ocean but since they haven’t measured to test this speculation they don’t know. This article claims to have found 20 % of it.
The most important and ignored part of the missing heat controversy is when the heat will return. ?
Since we are only speculating where the heat has gone and have only speculation about how it got there how can we predict how long it will be until it returns ?
Answer: We can’t ! We have a theory of CAGW which DEPENDS upon the “missing heat ” returning in the next 100 years and we don’t know where the heat is and don’t know if or when it will return. Since we cannot find it we cannot measure it so we don’t know much of it exists.
Despite all of this “the debate is over” and we should throw ten’s of trillions of dollars at the nearest politician to make it go away.

Chaveratti

It’s NOAA, they’ve just got a little themselves a little confused again.
“Heating” should daer read “cooling”.

pat

Hmmm. “Estimate temperature trends”. Why not “report” temperatures over 20 years or so?
I surely would not find it surprising that some areas within the oceans are heating a bit even as the ocean as a whole undergoes a cooling trend. But I am surprised it is a narrow zone below 4,000 meters near a continental pole that has been cooling slightly for the last 50 years.
On the other hand the absolute insignificance of this estimation is demonstrated by the fact that sea levels during the study period were abnormally stable world wide.

Colin from Mission B.C.

Must chime in to agree with Mike D above. It’s refreshing to see out-in-the-field science actually being done.

H.R.

“The abyssal warming produces a 0.053 (±0.017) mm yr−1 increase in global average sea level and the deep warming south of the Sub-Antarctic Front adds another 0.093 (±0.081) mm yr−1.”
How can they be certain it’s not +/- 0.0165327 mm/year? My super-calibrated ocean dipstick is reading 0.0536106 mm/year. I think they should remeasure ;o)
Seriously, I’m glad someone is out there on a boat taking measurements instead of modeling the “expected change.”

Elizabeth

“Global groundwater levels dwindling: study
‘You will have hunger and social unrest,’ researcher warns”
So, then, here is an example of humans altering sea level; however, it is not because of global warming.
Read more: http://www.cbc.ca/technology/story/2010/09/24/groundwater-study-depletion.html

John in NZ

Is it surprising that the abyssal temperatures are not constant?
If a temperature is rising, extrapolate it out 100 years. Nice and scary.
If it is falling then the warming is just taking a hiatus. Don’t worry, it’ll start warming soon.

James Evans

“Answer: We can’t ! We have a theory of CAGW which DEPENDS upon the ‘missing heat’ returning in the next 100 years and we don’t know where the heat is…”
I’ll check down the side of the couch.

jorgekafkazar

Mike D in Alberta says: “…at least this is a step up because it doesn’t state “we modelled the deep-oceanic temperatures and our models gave us the following data…””
My BS detector tells me that between these “highly accurate temperature measurements” lies a model.

UK Sceptic

So warm water sinks? Thermohaline circulation – ur doin it wrong…

Evan Jones

Could the increase in underwater volcanic activity around Antarctica have any measurable effect?

HelmutU

One or two years ago the Alfred Wegener Institut in Bremen Germany published their temperature-measurements in the deep waters around the Antarctic und found a cooling of the deep waters. Somebody must be wrong.

Dennis Cooper

Save money, defund NOAA, EPA, and The Dep of Energy. Lets put men on Mars.

R. de Haan

NASA should apologize for bad climate science.
Instead they are making it worse.

Vince Causey

The post reads, “Greenhouse gases in the atmosphere, such as carbon dioxide, cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy has gone into the ocean, warming it in the process.”
It should read: Greenhouse gases in the atmosphere, such as carbon dioxide, should cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy should have gone into the ocean, warming it in the process. Unfortunately, we can’t find it.
Until now, apparantly. My first reaction was: how did they measure the temperature below the floor of the Argo system. Then I spotted that the used a ship – not a fleet of ships, just a ship – and took the temperature by – measuring differences in salinity.
Is it me, or does this remind anyone of Parkers’ (I think) attempt to show that tropospheric temperatures agreed with surface trends by measuring – wind shear?

MikeTheDenier

I guess all those underwater volcanos spewing massive amounts of heat into the water have absolutely nothing to do with this. Nothing at all.

@ Chris H,
I think you may be right, the 800yr time lag shown in ice core data between raised temps, followed by raised C02 is usually explained by deep ocean warming as a result of the former causing the later.

Eric Anderson

” . . . over the past two decades find a warming trend that contributes to sea level rise, especially around Antarctica.”
Ah, so that explains the rise in sea ice extent around Antarctica. Hmmmm . . .

Ian W

“The scientists found the strongest deep warming around Antarctica, weakening with distance from its source as it spreads around the globe. “
Can someone explain in words of one syllable how Antarctica can be “the source” of deep ocean warming? The only sources of heat in that area are some volcanic activity… “Highly sensitive temperature probes moving continuously across the bottom of the volcano revealed signs of geothermal heating of seawater.”
http://www.sciencedaily.com/releases/2004/05/040527235943.htm

peterhodges

so co2 in the atmosphere somehow heats deep ocean water
yeah right
anyway, even if their measurements are accurate, the ocean is rising something like 1.4×10^-6% per year.
better start building that ark. oh, wait. you guys go ahead. i live at 7600ft.
at .o5 mm/year i have roughly 46 million years before i need to start worrying
😉

Considering that sea level rise practically stopped in the last years, I announce the whole article as misleading, based on non-actual data and unfounded speculations.
http://climexp.knmi.nl/data/l3a.png
http://climexp.knmi.nl/data/l2a.png
Dismissed!

Douglas Dc

So when a Big Nino occurs, doest some that heat escape?-into space?

It will be fascinating to read about their proposed mechanism for how the deep water got warmer — when the sun’s radiation hits only the top-most layer. Perhaps they will say that the Gulf Stream is warmer now, and as it reaches its sinking point near the Arctic that heat eventually reaches the ocean floor.
However, as I recall, that flow rate is rather slow, and the timing is not at all consistent with the “man-made global warming” of the past 35 years. If the deeps are warming now, the cause was likely from hundreds of years ago.
How about it, NOAA? Any mechanism to tell us about?

ShrNfr
John

evanmjones said at 9:23 am: “Could the increase in underwater volcanic activity around Antarctica have any measurable effect?”
That’s exactly what crossed my mind as I read this article. Always assuming that there really has been a temperature rise in the deep oceans, then surely a lot more likely cause could be an increase in ocean floor volcanic venting, which could then also lead to the oceans losing some of their CO2 into the atmosphere.
Surely that is a lot more credible than some rather tortured hypothesis based around CO2 indirectly causing the oceans to warm, particularly if this is occuring in the deep oceans rather than as a surface effect – why would atmospheric warming cause the deep oceans to warm before first raising the surface temperature?

kwik

Is this Lubchenko woman involved in this? In that case……

Richard111

“”Greenhouse gases in the atmosphere, such as carbon dioxide, cause heating of the Earth. Over the past few decades, at least 80 percent of this heat energy has gone into the ocean, warming it in the process””
I am beginning to wonder if NOAA release these papers to windup WUWT!
I was under the impression downwelling infrared radiation from CO2, from the
atmosphere no less, is completely absorbed by the first millimeter of the sea
surface thereby increasing surface evaporation which cools the sea surface.
But now the infrared radiation penetrates deeper into the oceans than sunlight.
You learn something new every day since CAGW became fashionable.

pochas

The deep ocean is the reason for the “underlying temperature trend”. The earth is cooler than it should be. The only thing preventing it from warming to its equilibrium temperature of 22 C is thermal inertia due to the cold reservoir in the deep oceans. The real question is, “Why did the deep oceans get so cold?”

Richard111 beat me to it.
If the measurements (so long since I could use that word insted of “models” so have to give them marks for that at least) show that deep water has warmed slightly then that is information of value. But attributing it to CO2? Nonsense. As Richard111 pointed out, CO2 radiates in the infrared spectrum which penetrates water to a paper thing depth. Being concentrated in such a thin layer, any energy absorbed by that paper thin layer results in a large temperature increase which in turn results pretty much instant evaporation. Not to mention that even if it didn’t, the average SST of the ocean being about 15 C, it is in a temperature range where warmer water would tend to rise, not sink. With no physical mechanism to move the heat content from CO2 to the depths of the oceans, all they have reported is some interesting data that has no more to do with warming from GHG than it does with the sinking of the Titanic.

John said at 10:07 am
evanmjones said at 9:23 am
I have done several ‘back of envelope’ calculations on volcanic heating of water (a while back) and come up with quite small numbers which may actually be worth revisiting in the light of this.

DirkH

HelmutU says:
September 26, 2010 at 9:24 am
“One or two years ago the Alfred Wegener Institut in Bremen Germany published their temperature-measurements in the deep waters around the Antarctic und found a cooling of the deep waters. Somebody must be wrong.”
Reported here:
http://www.nature.com/news/2008/080430/full/453015c.html

rbateman

Representing hundredths of a Watt per Meter Squared. Wow.
Reaching for a strong drink, the climatologist stumbles in the tangles mess of computer cables, printer paper, soda pop cans and pizza boxes, plunging headlong into the recycling bin, where they are found screaming the next day. The diagnosis is worse than previously imagined, the doctor is heard to say.

John from CA

Recent decadal warming and freshening of Antarctic-derived abyssal waters
Gregory Johnson
NOAA/Pacific Marine Environmental Laboratory, Seattle, WA, USA
IOP Conf. Series: Earth and Environmental Science 6 (2009)
source: http://iopp.fileburst.com/ees/ees9_6_032006.pdf
excerpts:
“The large distances between hydrographic sections, and the fact that they are reoccupied only from decade to decade makes quantification of the contribution of the observed recent abyssal warming to the global heat budget difficult. Quantification of the contribution of the warming and freshening observed to the global sea level rise budget is difficult for the same reasons.”
“Nevertheless, this qualitative analysis suggests that abyssal changes may play some role in global heat and sea level rise budgets.”
[like the image used related to the NOAA story — emphasis added for effect]
========
Note: if the “quantification of contribution” was difficult a year ago, what just changed?

John F. Hultquist

While I don’t think the results of this study are significant with respect to CAGW it is interesting and should be accepted for what it is. Namely, we have a great big ‘complex’ ocean on Earth and knowing more about it is a good thing. Further, studying its depths is difficult, time consuming, and expensive. Applause, please.
An issue questioned in some of the comments is how warmth from the surface could get into the ocean depths, insofar as “the hot/cold colored water experiment” [Ray @ 8”46 am] (been there – done that; with added salt too) suggests this shouldn’t happen. As WUWT commenters are an inventive bunch, it should be interesting to read of possible physical mechanisms how said transfers might proceed.
I have much to do today but will return with high expectations. Thanks, John

Stephen Wilde

The active sun of the late 20th century allowed the jetstreams and associated clouds to move poleward.
That allowed more solar shortwave into the oceans. That process has now ceased but some of the injected energy is still there.
I have proposed before that during a period of high solar input to the oceans some of that energy remains in the oceans and enters the thermohaline circulation to resurface some 1000 years later hence the climate cycling from MWP to LIA to date.
This paper would appear to support that proposition although a number of contributors tried to tell me trhat the downward mixing of that high solar input was minimal.
It is then somewhat of a lottery as to whether the energy coming out at the other end of that 1000 year oceanic cycling coincides with a period of high or low solar activity with the climate consequences varying accordingly.
Anyway, that extra energy in the oceans is from that higher solar shortwave input and nothing to do with CO2 because CO2 only produces more downward infra red which is immediately negated by faster evaporation.

crosspatch

I would be willing to bet that the amount of water pumped out of underground aquifers each year around the entire planet and added to the ocean is more than glacier retreat is adding.
Also, considering how long the LIA lasted and how short a period since the recovery from that event, I would expect the abyssal oceans to be continuing a recovery in temperature from that event and would expect that to continue for another century or so.

Dr. Dave

Several others have already commented about deep ocean volcanoes. If there actually is any measurable change in heat content 1,000 meters below the surface a more likely (and obvious) explanation would be underwater volcanism. I instinctively roll my eyes whenever I hear claims of “hidden heat” or (my favorite) “planetary thermal inertia”.
I also have an inherent distrust of a thermometer deployed from a boat that can accurately determine temperature to 0.03 deg C of resolution and that they have 2 decades of such data. The implication is that they measured temperature (from salinity?) just as accurately 20 years ago as they do today.
Color me skeptical. The authors’ conclusions have that distinct odor of desperation about them.

DCC

evanmjones said: “Could the increase in underwater volcanic activity around Antarctica have any measurable effect?”
Seems odd that this paper failed to mention an earlier conclusion that the missing heat could not be at depth else we would have noticed it in transit from the surface. Nor is there any discussion of why, of all places, this phenomenon should only exist in the Antarctic “weakening with distance from its source as it spreads around the globe.” As for warming that occurs at depth, but not elsewhere. who knew warm water would sink?
Methinks Dr. Trenberth is a bit too stuck on his prior conclusion that there is some missing heat. Whether that’s true or not, it doesn’t mean that he has found it.

R T Barker

I thought maybe they had already accounted for the missing heat. Section 5.5.3 Chapter 5 of the 4th IPCC report estimates the component of sea level rise due to thermal expansion as 1.6 mm/year (+ or – 0.5 mm) for the decade 1993 to 2003. For the period 1961 thru 2003 the estimate was 0.42 mm/ year (+ or – 0.12 mm). Aside from a mysterious change in the estimate of thermal expansion by a factor of 4 and the dismissal of other possible major contributors to sea level change, such as groundwater mining the analysts are closing the gap between estimates and observed. “Measure it with a micrometer, mark it with a grease pencil and cut it with an axe.” seems to apply.
Reference: Bindoff, N.L., J. Willebrand, V. Artale, A, Cazenave, J. Gregory, S. Gulev, K. Hanawa, C. Le Quéré, S. Levitus, Y. Nojiri, C.K. Shum, L.D.Talley and A. Unnikrishnan, 2007: Observations: Oceanic Climate Change and Sea Level. In: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Stephen Wilde

“Nor is there any discussion of why, of all places, this phenomenon should only exist in the Antarctic “weakening with distance from its source as it spreads around the globe.”
I don’t have a problem with that.
If the source of any ‘extra’ deep water energy is solar shortwave input from a period of active sun then the southern hemisphere being mostly water then I would expect the maximum effect south of the equator.
Then the thermohaline circulation takes it for a long tour around Antarctica before moving northward again.
Assuming their observations are correct in the first place (not guaranteed because they are desperate to find some ‘missing heat’) these findings would suit me nicely.