…that some of the warming nearer to the surface came from the deep ocean.
The paper is Liang et al. (2015) Vertical Redistribution of Oceanic Heat Content. The abstract reads (my boldface):
Estimated values of recent oceanic heat uptake are of order of a few tenths of a W/m2, and are a very small residual of air-sea exchanges with annual average regional magnitudes of hundreds of W/m2. Using a dynamically consistent state estimate, the redistribution of heat within the ocean is calculated over a 20-year period. The 20-year mean vertical heat flux shows strong variations in both the lateral and vertical directions, consistent with the ocean being a dynamically active and spatially complex heat exchanger. Between mixing and advection, the two processes determining the vertical heat transport in the deep ocean, advection plays a more important role in setting the spatial patterns of vertical heat exchange and its temporal variations. The global integral of vertical heat flux shows an upward heat transport in the deep ocean, suggesting a cooling trend in the deep ocean. These results support an inference that the near-surface thermal properties of the ocean are a consequence, at least in part, of internal redistributions of heat, some of which must reflect water that has undergone long trajectories since last exposure to the atmosphere. The small residual heat exchange with the atmosphere today is unlikely to represent the interaction with an ocean that was in thermal equilibrium at the start of global warming. An analogy is drawn with carbon-14 “reservoir ages” which range over hundreds to a thousand years.
A preprint edition of the paper is here. The paper is full of memorable quotes, including (my boldface):
An upward heat transport in the deep ocean may appear to be in conflict with the widespread idea that a large portion of the extra heat added to the Earth system in the past decades should be transported into the deep ocean (e.g. Fig. 1 in Stocker et al. 2013). That inference is based on the assumption that the ocean was in equilibrium with the atmosphere before any extra heat entered. When interpreting measurements of the ocean heat content, it is often assumed that the disturbances arise only from the recent past. However, as emphasized by Wunsch and Heimbach (2014) and the present analysis, the long integration times in the ocean circulation imply an observed response involving the time history of the circulation over hundreds of years, at least.
And contrary to climate models:
Furthermore the ocean, far from being a passive reservoir filled and emptied by the atmosphere, is a dynamically active, turbulent element of a coupled system.
And keeping in mind that Balmaseda et al. (2013) was one of the papers that claimed to have found part, but not all, of Trenberth’s “missing heat”:
Global average cooling in the deep ocean conflicts with some previous ocean heat content estimates (e.g. Balmaseda et al. 2013), but is consistent with the long thermal memory of the ocean, and with other recent studies (e.g. Durack et al. 2014; Llovel et al. 2014).
For more on Balmaseda et al. (2013) and Trenberth’s “missing heat”, see:
- Trenberth Still Searching for Missing Heat
- More On Trenberth’s Missing Heat
- Even More About Trenberth’s Missing Heat – An Eye Opening Comment by Roger Pielke Sr.
[My thanks to Judith Curry, who included a link to Liang et al. (2015) in her recent Week In Review dated March 13, 2015.]
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Reblogged this on Real Science.
One thing is for sure. If the oceans ate your warming, they are never giving it back.
This seems to be a good explanation for ocean heat transport and circulation and I even thought, gee, heat rises. I don’t quite understand understand how heat is transported from a cooler location to a warmer location, cooling the cooler. It seems a little different from any heat transfer things I’ve done.
Bob,the ocean has to be warming somewhere. This is evident from sea level rise (i dont buy the idea that sea level rise is meltwater). I don’t know who is right, but it seems to me these analyses are screwy because they fail to account for the geothermal emission. So I guess right now one has to conclude the additional heat which makes sea water swell is in the 700 meter to 2000 meter layer?
Reblogged this on TalmidimTeacher.
It must be hiding in the core. Al did say it was several million of degrees.
Didn’t know that GGs could overcome the second law didja. Powerful stuff!!
Reblogged this on Tallbloke's Talkshop and commented:
Oh my. Kevin Trenberth’s ‘Missing heat’ isn’t in the deep oceans, which have cooled since 1992 according to this new paper.
The complexity of these coupled systems is enormous. Attempts to point to one aspect as driving the whole system are doomed to mislead, and if exclusively relied upon, fail.
This overturning likely occurred where it normally does, mostly at the poles (but in minor ways elsewhere too where to topography forces slow bottom currents to rise closer to the surface. By the way, the phrase “Using a dynamically consistent state estimate, the redistribution of heat within the ocean is calculated over a 20-year period.” could be the newspeak for “model”. Not that I am freaked out by that. Thermo-fluid dynamics have been modeled for decades in arenas of industrial research development departments that had to focus on thermo-fluid dynamics in order to roll out innovative designs.
Bob, it would be instructive to (and you may have already done this) to show the stadium wave, that Judith proposes, in a series of graphs displaying how the El Nino equatorial peak in the late 90’s then appeared in subsequent ocean areas around the globe. It is of interest to me to see how the equatorial East Pacific is clearly stepping down in heat.
Great source of data you can play with.
Pamela Gray says:
March 14, 2015 at 12:39 pm
Not that I am freaked out by that. Thermo-fluid dynamics have been modeled for decades in arenas of industrial research development departments that had to focus on thermo-fluid dynamics in order to roll out innovative designs.
The models used in engineering for fluid dynamics don’t give you exact answers. More like “better” or “worse”. For exact answers you have to build something and test it. Once that is done you then add in generous margins until you have enough experience to tighten them.
Climate model touts act as if it is an exact science. But modelers know better. Which is why they do many runs and average them. And even then – if the chosen factors are wrong or not close enough – well you get useless garbage.
And there is no way to tell if the “different from everyone else” runs are the more correct (less correct) except by observation.
But “we will know something in 10 or 30 years” is no good if you are running a scare scam. If the scam is to have any chance of working sceptics must be silenced. There are moves afoot…
I think Global Deep-ocean cooling is indeed very bad news for missing heat seekers.
Heads are exploding all over the internet over this paper. Wherever it has been posted, without commenting on it, the poor slobs who still believe in the “settled science” have crawled out of the woodwork. Attacking Bob, and whoever posts the paper. LOL Good times!
Here’s one head exploder, poor baby.
A quick reading of the preview copy (sans figures) reveals no actual measurements of deep ocean temperature but rather inference from the integral of vertical flux.
“The global integral of vertical heat ﬂux shows an upward heat transport in the
deep ocean, suggesting a cooling trend in the deep ocean.”
The paper appears to ignore the second law of thermodynamics on many levels. The only physical ways the deep ocean can receive enthalpy from above is when the haline dominates the thermo per Chen and Tung, and when warmer water is entrained in wind forced currents in the mixed layer.
Aside from the .1W/m2 geothermal energy which is actually very strongly concentrated along tectonic lineations, there is simply no deep ocean enthalpy to transport upward. The thermohaline circulation input temperature remains essentially fixed by the absolute temperature of sea ice.
Eager to see fig. 1, but it is very easy to show that the unusual circumstances where air temperature exceeds ocean temperature and thereby transfers enthalpy to the ocean do not show up anywhere on the planet in monthly average data in the satellite era.
How can the thermohaline circulation input temperature remain constant when sea ice is salt-free 0 degrees and deep ocean is a salty 4 degrees?
Isn’t there a possibility of centuries long drift in the “average” temperature of the deep ocean modified by an inconsistent mixing from the thermohaline circulation.
Chic Bowdrie says:
March 15, 2015 at 6:01 pm
The bottom of the ocean is 4degC because water is densest at that temperature. Colder water is going to tend to rise. Things get interesting don’t they?
Chic, current thinking is that seawater freezes at about -2 C at the edge of the ice and the brine rejected additional salinity seals the deal for the downward bound thermohaline input. This temperature will not change until the ice is gone (the normal earth condition) or until it retreats to some point where bottom water formation areas change.
Some very smart people, including Berenyi Peter, have pointed out that the thermal, even with the saline factor, gradient is way too small to drive the thermohaline circulation as a heat/density engine. My own suspicion is that the Antarctic vortex acts as a centrifugal pump.
gymnosperm, obviously I didn’t know the -2 C. It probably doesn’t mean anything that it is about and not exactly. What does seem important to me is the rate and duration of melting which must be influenced greatly by surface temperatures. As ignorant I am on thermohaline circulation, I never considered a thermal gradient contributing anything. Antarctic vortex as as centrifugal force. Interesting.
MSimon: “Things get interesting.” Yes they do. Lot’s to learn in climate science.
“Colder water is going to tend to rise.”
It depends on the salt content doesn’t it? If I remember correctly, salt water density doesn’t change to much between 0 and 4 C. Anyone have that data handy?
Chic, freezing applies to the thermohaline input temperature, not melting. Thermohaline input is thought to occur during the winter when the ice is expanding. Freshwater input from melting or catastrophic failure of ice dams has long been posited as a damping mechanism. Makes sense. Jeff Severinghaus and Richard Alley think cyclic freshwater input may explain the sub oscillation of temperature between the poles.
OK, so freshwater melted from snow and ice burgs is minor compared to freezing/melting of sea water/ice. It does make sense, because there’s no way less dense fresh water could descend. Thanks for straightening me out on this.
Ben Wouters also had some helpful comments for me at tallbloke’s talkshop.
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