This paper is to be published on-line on Friday in Physics Letters A Dr. Douglas graciously sent me an advance copy, of which I’m printing some excerpts. Douglas and Knox show some correlations between Top-of-atmosphere radiation imbalance and the Pacific Decadal Oscillation (PDO). The authors credit Dr. Roger Pielke Sr. with reviving interest on the subject due to his discussions on using ocean heat content as a metric for climate change.
Abstract
Ocean heat content and Earth’s radiation imbalance
D.H. Douglass and R, S, Knox
Dept. of Physics and Astronomy, University of Rochester, PO Box 270171, Rochester, NY 14627-0171, USA
Earth’s radiation imbalance is determined from ocean heat content data and compared with results of direct measurements. Distinct time intervals of alternating positive and negative values are found: 1960–mid-1970s (−0.15), mid-1970s–2000 (+0.15), 2001–present (−0.2 W/m2), and are consistent with prior reports. These climate shifts limit climate predictability.
Introduction:
A strong connection between Earth’s radiative imbalance and the heat content of the oceans has been known for some time (see, e.g., Peixoto and Oort [1]). The heat content has played an important role in recent discussions of climate change, and Pielke [2] has revived interest in its relationship with radiation. Many previous papers have emphasized the importance of heat content of the ocean, particularly the upper ocean, as a diagnostic for changes in the climate system [3–7]. In this work we analyze recent heat content data sets, compare them with corresponding data on radiative imbalance, and point out certain irregularities that can be associated with climate shifts. In Section 2 the conservation of energy is applied to the climate system and the approximations involved in making the radiationheat content connection are discussed. In Section 3 data sources are enumerated. Section 4 gives the radiation imbalance for the Earth’s climate system. In Section 5, climate shifts, radiative imbalances and other climate parameters are discussed. A summary is in Section 6.
Discussion:
…
What is the cause of these climate shifts? We suggest that the low frequency component of the Pacific Decade Oscillation (PDO) may be involved. The PDO index changes from positive to negative near 1960; it remains negative until the mid-1970s where it
becomes positive; then it becomes negative again at about 2000. This mimics the FTOA data. The PDO index is one of the inputs in the synchronization analysis of Swanson and Tsonis [43]. One would like to be able to predict future climate. Such predictions are based upon the present initial conditions and some expectation that changes in the climate state are continuous. However, if there are abrupt changes such as reported by Swanson and Tsonis then this is not possible. These abrupt changes presumably
occur because the existing state is no longer stable and there is a transition to a new stable state.
Summary:
We determine Earth’s radiation imbalance by analyzing three recent independent observational ocean heat content determinations for the period 1950 to 2008 and compare the results with direct measurements by satellites. A large annual term is found in both the implied radiation imbalance and the direct measurements. Its magnitude and phase confirm earlier observations that delivery of the energy to the ocean is rapid, thus eliminating the possibility of long time constants associated with the bulk of the heat transferred. Longer-term averages of the observed imbalance are not only many-fold smaller than theoretically derived values, but also oscillate in sign. These facts are not found among the theoretical
predictions.
Three distinct time intervals of alternating positive and negative imbalance are found: 1960 to the mid 1970s, the mid 1970s to
2000 and 2001 to present. The respective mean values of radiation imbalance are −0.15, +0.15, and −0.2 to −0.3. These observations are consistent with the occurrence of climate shifts at 1960, the mid-1970s, and early 2001 identified by Swanson and Tsonis. Knowledge of the complex atmospheric-ocean physical processes is not involved or required in making these findings. Global surface temperatures as a function of time are also not required to be known.
Nasif Nahle (10:46:57) :
I do not buy that.
So, you then also do not buy that the oceans contain heat [the first three words of the topic of this thread is ‘ocean heat content’]. Perhaps you should write a letter to the editor of Physics Letters A to point out that he and the peer-review process have failed in allowing a paper with such a title to be published…
Is the PDO regime still negative? Or has it moderated because of the recent warm SSTs?
@ur momisugly George E. Smith (10:28:02) : RE: Sampling theory.
I’ll second that motion. And also offer a fairly decent primer on such things – http://www.statsoft.com/textbook/stathome.html . In the Process Analysis section.
“I certainly don’t think that the oceans act as a very long period capacitor, but they do have capacity. ”
I have always wondered about the effects of pressure on the specific heat capacity of water. At the bottom of the ocean the pressure is huge and the amount of heat required to change its temperature must be much greater than at the surface.
Does anyone know the physics behind this?
RE: “If so, debunks the idea [kicked around many times on this blog] of the oceans storing the heat of past high solar cycles to release it when cycles are low.”
To further Anthony’s electrical circuit analogy, there is little to no series inductance, therefore the “cap” can discharge rapidly “when the discharge circuit is closed.”
George E. Smith wrote:
“Measuring the ocean’s heat content is even more troublesome than measurting the earth’s mean surface temperature, because that heat content problem is a three dimensional problem, whereas surface temperature is only two dimensions.”
Careful, man, they’ll accuse you of thinking the Earth is Flat! 🙂
I get your point, and agree, I think… but there has to be a better way to phrase this. “Relatively two-dimensional”???
Best,
Frank
Leif Svalgaard (11:31:14) :
So, you then also do not buy that the oceans contain heat [the first three words of the topic of this thread is ‘ocean heat content’].
I think you should read some of his comments above where he specifically states this that oceans do not contain heat, they contain energy.
From the wiki:
which implies that Nasif’s usage is correct, i.e., heat is more correctly described as the transfer of energy, not energy itself.
Nasif: I have a similar problem with the rather annoying usage of feedback terminology. I’ve all but given up the fight due to overwhelming opposition. I need more control theory experts to post in here in my defense. That and when to use an apostrophe with a trailing “s,” hehe. The latter is equally unwinnable.
Mark
RE: “The flow is always sun to oceans to air to space. It cannot be reversed. Only the speed can be changed.”
Space is “ground” / “earth” potential. The “speed” is the integral of all thermal resistance terms.
steve (08:17:22) :
“Just to give some relative sense of scale, the Three gorges dam is around 30 cubic km once filled. The thermal expansion of the oceans is around 5400 cubic km and that’s just 1993-2003.”
That’s interesting tallbloke but hardly relative to all the land sequestration of water involved. If you have the scientific evidence to show new dam construction is minor when measuring sea level variations then perhaps you should publish a rebuttal to the paper I cited which was peer reviewed and in a reputable journal.
What I pointed out was that the IPCC already allowed for land use change in their estimate. How correct they are is, as I also pointed out, debatable.
Your peer reviewed paper is one document among thousands of peer reviewed papers which conflict with each other. If you believe one rather than another, I’m sure you have reasons for your preference, but unless you choose to be clear about what they are, I’m not sure how we proceed to making sense of the conflicting estimates. I’m not in general a big fan of the IPCC, but they did at least set up a pretty wide ranging system for comparing data. Did the authors of your paper contribute to the process or complain about being excluded from it ?
Re: “These observations are consistent with the occurrence of climate shifts at 1960, the mid-1970s, and early 2001 identified by Swanson and Tsonis. Knowledge of the complex atmospheric-ocean physical processes is not involved or required in making these findings. Global surface temperatures as a function of time are also not required to be known.”
As the fictional Mr. Spock might say, “Fascinating”.
Leif Svalgaard (09:19:28) :
Nogw (07:46:41) :
FAO uses LOD (Length of the day) to succesfully predict sea temperatures in order to forecast fish catches
No, they do not. Because LOD is not forecast. What they noted was that there is a 55-60 year cycle in the catches and also in LOD. Good catch depends on temperature, moment of inertia of oceans and atmosphere depends on temperature, and LOD therefore also.
If you take the trouble to actually read the NAO document, rather than shooting from the hip at any post mentioning LOD, you’ll see that they do indeed assert that due to the offset of their fit of LOD to temperature, they are able to offer a six year prediction.
90% of LOD change is caused by the altering of currents under the earth’s crust. You are confusing this with the 10% of LOD variation due to the atmosphere/ocean energy exchange.
Dr Richard Gross of NASA, who compiled the LOD series back to 1832 says this is so. I guess he should know.
George thinks I am a student of Nasif, and Nasif thinks I am an AGWer. This is tough threading! Guys, all I did was suggest that one could think of the oceans as not having heat energy if there was no means of using that heat in any way. If one couldn’t transport it. If we have to make every tiny point absolutely clear then we begin to seem like pedants. I apologize for using the term, though.
This is the last I write on this point, because there are more interesting issues in this thread to think about.
Leif Svalgaard (11:31:14) :
Nasif Nahle (10:46:57) :
I do not buy that.
So, you then also do not buy that the oceans contain heat [the first three words of the topic of this thread is ‘ocean heat content’]. Perhaps you should write a letter to the editor of Physics Letters A to point out that he and the peer-review process have failed in allowing a paper with such a title to be published
Dumb words usually fall on deaf ears.
Bob Tisdale (09:29:39)
http://i42.tinypic.com/e9b04g.jpg
Very interesting perspective.
–
For anyone thinking, “I don’t have time to watch these anomaly videos Bob posts”: You may be missing the point. Just because the yo-yo goes up & down does not mean the hand is not moving…
Mark T (12:12:30) :
which implies that Nasif’s usage is correct, i.e., heat is more correctly described as the transfer of energy, not energy itself.
It is not about being ‘correct’, but about being sensible and useful. The title could not have been ‘ocean energy content’, because that would not have been correct in a physical sense. The kinetic energy of the ocean currents, for example, is not included. One could perhaps have said ‘ocean thermal energy content’ but that is cumbersome and in communication the easy forms always win and by there usage establish what is correct terminology. Trying to go against that is ultimately a losing proposition.
Even trying to apply the ‘correct’ old thermodynamic definition can get you in trouble when confronted with reality. We speak of how to account or explain ‘coronal heating’. The 2nd law prevented understanding of that process for half a century. It has been suggested since the 1880s that the corona was extremely hot [millions of degrees] because of its great extent and spectral characteristics, yet the understanding of this was held back until the 1930s because it was deemed impossible to heat a million-degree corona by a 6000-degree photosphere. So, we should not be allowed to talk about heating the corona. I submit that ‘heating the corona’ and ‘ocean heat content’ and similar terminology is useful [and is in fact the accepted usage], and that this is not misuse or misleading.
So blinded is Nasif that he was trying to convince us that the units for ‘amount of heat’ is Watt and not Joule. I see no reason to nitpick against the use of the term ‘ocean heat content’ as being misuse. Correct use is what is being used by researchers in a field.
tallbloke (13:10:47) :
90% of LOD change is caused by the altering of currents under the earth’s crust.
But that is not what regulates SST.
Nasif Nahle (13:20:33) :
“Perhaps you should write a letter to the editor of Physics Letters A to point out that he and the peer-review process have failed in allowing a paper with such a title to be published”
Dumb words usually fall on deaf ears.
I’m reasonably sure that if you phrase your words carefully and forcefully and with loads of references to authorities that the ears might be a less deaf than you surmise.
tallbloke (13:10:47) :
7.1 SUMMARY
Regular climate changes have taken place over the last millennium with a period of 55–65 years.
Period.
************
Mark T (12:12:30) :
Leif Svalgaard (11:31:14) :
So, you then also do not buy that the oceans contain heat [the first three words of the topic of this thread is ‘ocean heat content’].
I think you should read some of his comments above where he specifically states this that oceans do not contain heat, they contain energy.
From the wiki:
heat is the process of energy transfer from one body or system due to thermal contact
which implies that Nasif’s usage is correct, i.e., heat is more correctly described as the transfer of energy, not energy itself.
Nasif: I have a similar problem with the rather annoying usage of feedback terminology. I’ve all but given up the fight due to overwhelming opposition. I need more control theory experts to post in here in my defense. That and when to use an apostrophe with a trailing “s,” hehe. The latter is equally unwinnable.
Mark
*************
That form of the word heat is from the verb: to heat.
There is nothing wrong with that usage, but the usage described in the link below is more relevant to the article.
http://id.mind.net/~zona/mstm/physics/mechanics/energy/heatAndTemperature/heatAndTemperature.html
Leif Svalgaard (13:33:22) :
tallbloke (13:10:47) :
90% of LOD change is caused by the altering of currents under the earth’s crust.
But that is not what regulates SST.
The short term changes in LOD (bi-annual) affect short term changes in SST (bi-annual)
The long term changes in LOD (multi-decadal) affect long term changes in SST (multi-decadal).
Mark T (12:12:30) :
“From the wiki:
heat is the process of energy transfer from one body or system due to thermal contact
which implies that Nasif’s usage is correct, i.e., heat is more correctly described as the transfer of energy, not energy itself.”
From Chambers Science and Technology Dictionary (1991):
“However, the term is still used also to refer to the energy contained in a sample of matter.”
From the Routledge Encyclopedia of Philosophy:
“The principle of charity governs the interpretation of the beliefs and utterances of others. It urges charitable interpretation, meaning interpretation that maximizes the truth or rationality of what others think and say.”
SteveSadlov (12:09:17) :
RE: “If so, debunks the idea [kicked around many times on this blog] of the oceans storing the heat of past high solar cycles to release it when cycles are low.”
To further Anthony’s electrical circuit analogy, there is little to no series inductance, therefore the “cap” can discharge rapidly “when the discharge circuit is closed.”
No, the “cap” can discharge rapidly ONLY if the resistance over which it discharges is low. Even without inductance
However, if the input/output of this “cap-resistor” system is cyclical, we’ll see phase lags of up to 1/4 cycle length.
Sorry, could not resist. 🙂
“The short term changes in LOD (bi-annual) affect short term changes in SST (bi-annual)”
I should have added: and are affected by short term changes in SST also. It’s a resonant feedback situation.
L: The term “Civil Servant” is an oxymoron – they are never civil and they are certainly not servants – nor of any useful service. Observation and having worked to them for longer, perhaps, than was sensible. But you have to eat.
This thread seems to have become fixated on the meaning of heat. Whether heat is energy or not is arguable, but in retrospect we should define what we are trying to measure.
I was taught in physics that energy is the capacity to do work. I also learned in thermodynamics that heat can only do work if there is a heat gradient. Indeed, before we learned that we were all going to die by a big Rip in cosmological terms, astronomers speculated that the universe might end in the ‘heat death’. Something of a misnomer perhaps, it meant simply that they thought eventually all heat gradients would disappear and the entire universe would be permeated by heat energy of a uniform nature – that is, entropy would be at a maximum. The reason this was deemed a bad thing to have happen, is quite simply because no work can be done when the entire universe is pervaded by a single temperature. The paradox is that although heat exists everywhere, no work can be done. I take that to be an a priori argument for no energy to exist.
So, heat does not mean energy necessarily, but it depends what we are trying to measure. My understanding of use of oceans as a heat sink, is that it can be a metric for global warming. That is, if there is a radiative imbalance of so many watts/m2, then this must show up somewhere. If this goes into the oceans, then it results in an increase in ocean temps. Therefore, we are looking for anomalies in ocean heat from which we can calculate the radiative imbalance. On the other hand, the question is can that ocean heat be given up? This must be the case whether one thinks of it as energy or not.
Confusing isn’t it?