Related to this story: The Pacific Decadal Oscillation Time Series from the University of Washington, seen below. Emphasis points mine. h/t to WUWT reader Richard Heg. – Anthony
Monthly Values for the PDO Index, January 1900 to September 2008. Positive (red) index values indicate a warm phase PDO; negative (blue) index values indicate a cool phase PDO. While short-term flips in PDO phases do occur, evaluation of 20th century instrumental records has shown that PDO phases generally persist for 20-30 years, as indicated in this figure. To download the data, see Nate Mantua’s PDO page.
Changes in Net Flow of Ocean Heat Correlate with Past Climate Anomalies
Physicists at the University of Rochester have combed through data from satellites and ocean buoys and found evidence that in the last 50 years, the net flow of heat into and out of the oceans has changed direction three times.
These shifts in the balance of heat absorbed from the sun and radiated from the oceans correlate well with past anomalies that have been associated with abrupt shifts in the earth’s climate, say the researchers. These anomalies include changes in normal storm intensities, unusual land temperatures, and a large drop in salmon populations along the western United States.
The physicists also say these changes in ocean heat-flow direction should be taken into account when predicting global climate because the oceans represent 90 percent of the total heat in the earth’s climate system.
The study, which will appear in an upcoming issue of Physics Letters A, differs from most previous studies in two ways, the researchers say. First, the physicists look at the overall heat content of the Earth’s climate system, measuring the net balance of radiation from both the sun and Earth. And second, it analyzes more completely the data sets the researchers believe are of the highest quality, and not those that are less robust.
“These shifts happened relatively abruptly,” says David Douglass, professor of physics at the University of Rochester, and co-author of the paper. “One, for example, happened between 1976 and 1977, right when a number of other climate-related phenomenona were happening, such as significant changes in U. S. precipitation.”
Douglass says the last oceanic shift occurred about 10 years ago, and that the oceans are currently emitting slightly more radiation than they are receiving.
The members of the team, which includes Robert Knox, emeritus professor of physics at the University, believe these heat-flux shifts had previously gone unnoticed because no one had analyzed the data as thoroughly as the Rochester team has.
The team believes that the oceans may change how much they absorb and radiate depending on factors such as shifts in ocean currents that might change how the deep water and surface waters exchange heat. In addition to the correlation with strange global effects that some scientists suspect were caused by climate shifts, the team says their data shows the oceans are not continuously warming—a conclusion not consistent with the idea that the oceans may be harboring “warming in the pipeline.” Douglass further notes that the team found no correlation between the shifts and atmospheric carbon dioxide concentration.
“An interesting aspect of this research is that no reference to the surface temperature itself is needed,” says Knox. “The heat content data we used, gathered by oceanographers, was gleaned from temperature measurements at various ocean depths up to 750 meters.” The team also found that the radiative imbalance was sufficiently small that it was necessary to consider the effect of geothermal heating. Knox believes this is the first time this additional source of heat has been accounted for in such a model.
The team notes that it’s impossible to predict when another shift might occur, but they suspect future shifts might be similar to the three observed. Both Douglass and Knox are continuing to analyze various climate-related data to find any new information or correlations that may have so far gone unnoticed.
As regards geothermal output being a couple of orders of magnitude different than solar input, it’s a much bigger difference:
Solar=1.365 X 10^3 W/m^2 Geothermal=8.2 X 10^-2 W/m^2
OT This report on bbc web page today… A few years ago a report like this would have troubled me…. Now I just don’t believe such findings anymore… yet they may be true! This is what happens when science is politicised!!
http://news.bbc.co.uk/1/hi/sci/tech/8205864.stm
For those that don’t want to bother opening it… it is another finding along the lines of OMG its all Much worse than we expected and we thought it was bad before!! Methane escaping as ice melts near Spitzbergen. Yet arctic ice not that different to any time in last 30yrs….
Is there a free version of the paper online? The ScienceDirect site wants $31.50 — which seems a lot for a paper I likely won’t understand 😉
But I would like to at least try to read the whole thing.
Thanks,
tim
Allen63 (03:40:00) wrote:
“Interesting that they think geothermal heating is a factor.
A relative (here in Ohio) uses geothermal heating to heat his entire house. The heat is gathered by a heat pump at a depth of a few feet in his back yard from a grid of underground pipes. I considered it myself (but have gone with a standard air heat pump/furnace combined system).
The fact that geothermal is practical for home heating at such shallow depths using only part of the area of a “back yard” has lead me to speculate geothermal is a factor in global temperature. Probably more so in the ocean where the crust is slightly thinner and, apparently, thousands of underwater magma vents exist. I wondered when a scientific study might ascertain that connection.”
Strictly speaking, Allen’s relative isn’t using “geothermal” heating. Rather, he’s using a heat-pump system with the ground in his back yard as the outside heat sink. During the summer his system heats the ground in the back yard by pumping thermal energy out of the house and into the ground (that’s ‘air conditioning’ the house). During the winter, his system pumps thermal energy from the ground in the back yard into the house (thus cooling the ground and heating the house).
The reason such systems are so efficient is that pumping heat around is 3x-6x more efficient than direct heating or cooling (depending on the specific technologies used). When sized correctly, this is a GREAT approach for heating and cooling your house. The biggest drawbacks are installation cost and the need for backup heating and cooling for those days when extreme outside temperatures lead to a need for more heating (or cooling) capacity than the system can deliver.
What we normally call “geothermal” heating would be more like what they do in Iceland — drill down into a volcanically active area and pump water through it. This heats the water “for free” (and may even boil it, providing steam).
Xenophon
(A knowledgeable lay-person, but NOT a professional engineer)
lgl (01:10:34) “Why did the sea level rise also betweeen 1940 and 1970 if the net radiation was from the ocean? Can’t imagine it was due to melting ice.”
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Probably more to do with bad siting of the measuring equipment…. The baseline for the East Coast of Australian is situated on a Jetty…. Not very accurate…. the jetty can sink… The land can subside…. etc.
I had a link to a picture and an article on it…. But I can’t find it now.
Wade (06:26:14) :
“There is one thing for certain: climate is very complex with many variables that are not fully understood.”
Spot on there. And anyone who tries to tell you that they can model it using a few grammes of silicon is shooting the bull big style.
Salmon go where the plankton blooms in extravagant numbers, which occurs on a multidecadal cycle. The extravagant bloom changes location from off the coast of Alaska to off the coast of California depending on the PDO phase. Fishing vessel records going back to the previous century documented this phenomenon along with ocean temperatures, which was the source of the discovery of the PDO. With cold oceans in the Northern Pacific Ocean, plankton blooms because of nutrient rich waters (upwelling of shallow waters as well as wind blown dust) there. Eventually warm waters return to this area and plankton is not as abundant. However, at the end of the cold PDO when California and the Dust Bowl blows nutrients into the coastal waters and shallow mixing brings up nutrients there, plankton blooms in abundance, leading to renewed salmon runs in that area. The population of salmon in oceans and rivers grows and shrinks in tune with these oceanic blooms. Overfishing occurs when catch is not restricted during the down cycle.
J.Hansford (08:16:10) :
lgl (01:10:34):
Measuring sea level rise is a bit like measuring a global temperature. (To paraphrase Swiss Tony from the excellent BBC TV series “The Fast Show” – Johnny Depp is a great fan.)
There are probably very few places on the earth’s surface that are not either subsiding or uplifting due to tectonic processes. Those that are stable at the moment probably won’t be for very long…
But it’s not our fault. Again.
Joe. Good points. IMHO, we don’t know enough about Geothermal to assign quantitative values to it. It is the great unknown. Why is it that atmosperic temps. are adjusted due to volcanic eruptions, but geothermal contributiuons are deemed to be so small as to be ignored? fm
As regards geothermal we seem not to need it to adequately account for all past climate changes but it may well have an influence on the timing of changes in ocean phases.
I know the oceans store a vast amount of energy, but it occured to me that they are a relatively trivial mass. Assuming an average depth of 3 miles X 70 % = 2.1 miles of earth’s surface. Earth’s radius of 4,000 miles gives ocean as 2.1/4000 = .000525 ISTM, if one could ” hold ” the earth it would merely feel damp. Given that the weight of fresh water is 62.4 lbs./ cubic foot, and rock/soil is approx. 110 lbs./ cubic foot, it seems to me that the energy stored in the earth is hugely greater than that stored in the oceans. I doubt that we know very much about the rate of release. fm
“I could be wrong but if the ocean water is cooling, that will cause expansion.”
Water only expands on cooling below 4 degrees C (39.2F); above that, it expands again. My understanding is that the molecules are organizing into a position where they can crystallize, and the distances in the crystal are greater than the distance in the cool liquid.
Water only expands on cooling below 4 degrees C (39.2F); above that, it expands again.
The relationship is not the same for sea water. The density monotonically decreases down to the freezing point for the oceans due to its salinity.
Mark
A little OT, but we’re talking about thermal energy storage in water after all 🙂
Allen63 (03:40:00) wrote:
“…A relative (here in Ohio) uses geothermal heating to heat his entire house. The heat is gathered by a heat pump at a depth of a few feet in his back yard from a grid of underground pipes. I considered it myself (but have gone with a standard air heat pump/furnace combined system).”
A friend of mine here in SoCal has a very effective variation on this theme. He build a heat exchanger for his AC/heat-pump to pump thermal energy into/out-of his swimming pool.
In the summer his AC system cools the house and heats the pool. If the pool gets too warm to swim in, he runs the pool water at night through pool heater panels on his roof, so the water gets radiatively cooled down.
In the winter the opposite happens, during the day the heater panels gather enough solar heat energy so the water does not get too cold (it’s too cold for swimming anyway).
The system is VERY effective, much more so than an air-source heat pump. And it’s also very cheap compared to ground sourcing.
Frank Mosher (09:07:32)
The mass of the oceans is trivial compared to the mass of the Earth but huge compared to the mass of the air.
However the Earth’s crust is not penetrated much by solar energy (much is covered by water anyway) so that energy is quickly lost to space again.
Air doesn’t retain solar energy either save to a trivial extent as per the findings of Tyndall et al (though they thought it was all important).
The largest solar energy retaining (and manipulating) medium by far is the oceans. That is where we must look for a coherent climate overview.
There is in fact more energy stored in the Earth than in the oceans but it is geothermal energy not solar energy and leaks out rather slowly or in intermittent bursts. The slow leakage sets the base temperature below which the temperature of the bottom of the oceans cannot drop.
The intermittent bursts may have an influence on the timing and/or intensity of oceanic phase changes as regards the rate of releases of energy to the air.
Just to remind folk that PDO data is also available at WFT, if you want to play with it yourselves:
http://www.woodfortrees.org/plot/jisao-pdo/mean:60
Stephen Wilde. Thanks for your observations. I always find them instructive. I am curious about the intermittent bursts, and their effect. It seems apparent the PDO signature is evident in climate. The Rim of Fire, circling the Pacific is well known, as is the thermally active Indonesian area. I have always found it interesting that the Pacific Warm Pool exists in a known geologically active area, and that to rule out posible geothermal contribution is reckless. fm
woodfortrees (Paul Clark) (10:17:48) : Thanks for the tip Paul. I wish you’d put up some more data sets and analysis techniques-you have the best graphing tool I have seen! Maybe you can add a way to put “custom” time series?
Yes, that’s correct. I was just attempting to explain the comment I responded to, upthread, that stated that water becomes less dense as it gets colder. Fresh water does that, between 4 degrees C and 0 degrees C, but above 4 degrees C it expands with temperature, which would make sea levels rise with temperature, not fall as you’d expect with a substance that has (reaching, here) a negative coefficient of thermal expansion.
Frank Mosher (10:39:03)
Thanks Frank.
As regards those intermittent bursts of geothermal energy I also think it relevant that those El Nino events occur in such an active region. I’ve also noted that in the same region we have the deepest ocean trenches where the crust is at it’s thinnest so the energy transfer from the interior must be at it’s fastest straight into the deepest parts of the Pacific.
However the problem then is that 30/60 year periodicity which is too regular for any known volcanic influence and it also gives problems for all those whose ideas rely on changes in the air as primary climate drivers
There are no 30/60 periodicities in the air either so I am forced to regard it as an internal oceanic variability which has not yet been adequately described.
My favourite idea so far is that whether the background solar trend is towards warming or towards cooling the steady solar change in input to the oceans gradually destabilises some internal oceanic feature which then flips periodically as the oceans adjust in steps to the solar changes.
Thus during a background solar warming spell the excess energy buids up slowly then gets released over the next positive oceanic phase and builds up again during the subsequent negative phase and so on thereby giving a ‘stepped’ progression of global warming.
During a background solar cooling a deficit builds up slowly then gets restored during the next negative oceanic phase with the deficit increasing again during the subsequent positive phase so one gets the same ‘stepped’ pattern on the way down as well.
That’s my best guess at the moment but I’m looking for other possibilities.
lgl (05:40:04)
We are probably on the same track as regards sun and ocean but probably diverge on the CO2 issue.
I’m a bit out on a limb there because the logic of my climate description forces me to the conclusion that the GHGs in the air have no measurable effect in the face of the natural solar and oceanic changes.
In particular the role of the hydrological cycle in changing the rate of energy transfer from surface to space is overwhelming so to deal with human CO2 we probably only need a latitudinal shift of a tiny amount in the air circulation systems to negate it (possibly in the order of less than one mile). In contrast those air circulation systems shift hundreds of miles poleward or equatorward in response to changes in the rate of energy emission from the oceans.
We shall see.
Stephen Wilde,
I know very little about this but it seems that there may literally be millions of underwater volcanoes on the ocean floors, emitting heat at various rates and times about which we know little.
Whilst such volcanoes may not actually be able to affect greatly the temperature of the oceans in bulk is it not possible that underwater volcanic activity could coincide with other factors to produce changes at the surface – a bit like tipping points?
Your comments would be welcome.
Re: Richard Mackey (04:17:56)
Thanks for the notes.
It’s not just LNC:
http://www.sfu.ca/~plv/ClimateRegimeChangePoints.PNG
(This draft plot is before even including info about LNC.)
Depending on political dynamics, the mainstream might soon be piling on natural factors and claiming them as their discovery. It might be decades before the truth is made (fully) public about why this knowledge was obstructed from public view for decades. By now the authorities should be realizing they can’t block this knowledge from view for much longer. Statistical methods which have emerged over the past few decades make it too easy to discover the change-points independently. The only way around that: Manipulating the data released to the public… (e.g. see the recent argument to change ~1945 SSTs by a lot)…
Bob Tisdale (01:40:40) “[…] climate shifts […] Has anyone run into a paper about OHC prior to 1948?”
You may note that 1948 & 1950 are popular cut-off dates for a variety of studies & [public versions of] time series. The Chandler wobble frequency stabilized ~1940 and the precision of the polar motion record improved dramatically a few years later. It is easier for the authorities to introduce a convenient temporal-boundary than to overcome their poor understanding of phase relations during earlier times. Like you, I await focus on earlier dates. Priority 1 has to be explaining reversals in phase relations (e.g. SST / solar; PPT / solar). Otherwise people (including regulars here) are going to continue making the same (ongoing) mistake of thinking recent phase-relation patterns can be extrapolated backwards in time to pre-1940. We need to keep hammering this until the mainstream authorities have no choice but to deal with it. 1931 is the inconvenient point in the records that mainstream authorities canNOT evade. Serious, truthful, unreserved scientists who look at ~1931 carefully are going to start noticing things that many alarmists are categorically not going to like. It will be interesting to see if people start proposing radical “corrections” to 1915-1945 records that “can’t possibly be right”.
pinkisbrain (01:04:03) :
Jim Masterson (23:44:43) :
Geothermal is on the order of tens to hundreds of milliwatts per square meter. Compared to climate heat flows, it is usually too small to bother with.
yes, but geothermal, vulcanic activities under the oceans may initiate little shifts in ocean drifts and may produce a regional heat exchange in deep water aereas.
Within the mid-ocean rift zone and around submarive volcanoes the rate might be so large as watts or even tens of watts per squared meter. Take a look at a vent in the mid-ocean ridge–looks like a rocket engine on a test stand. Still, I am surprised that it makes much of a difference globally in normal circumstances.