Four out of five ARGO data studies now show Ocean Heat Content declining
Readers may recall that Dr. Kevin Trenberth said this in one of the Climategate emails:
“The fact is that we can’t account for the lack of warming at the moment and it is a travesty that we can’t.”
Using the ARGO ocean buoy data from Josh Willis, Knox and Douglass still can’t find that missing heat in this paper published in the International Journal of Geosciences, currently in press here.
Recent energy balance of Earth
R. S. Knox and D. H. Douglass
Department of Physics and Astronomy, University of Rochester, Rochester, NY
Abstract
A recently published estimate of Earth’s global warming trend is 0.63 ± 0.28 W/m2, as calculated from ocean heat content anomaly data spanning 1993–2008. This value is not representative of the recent (2003–2008) warming/cooling rate because of a “flattening” that occurred around 2001–2002. Using only 2003–2008 data from Argo floats, we find
by four different algorithms that the recent trend ranges from –0.010 to –0.160 W/m2 with a typical error bar of ±0.2 W/m2. These results fail to support the existence of a frequently-cited large positive computed radiative imbalance.
1. Introduction
Recently Lyman et al. [1] have estimated a robust global warming trend of 0.63 ± 0.28 W/m2 for Earth during 1993–2008, calculated from ocean heat content anomaly
(OHC) data. This value is not representative of the recent (2003–2008) warming/cooling rate because of a “flattening” that occurred around 2001–2002. Using only 2003-2008 data, we find cooling, not warming.
This result does not support the existence of a large frequently- cited positive computed radiative imbalance (see, for example, Trenberth and Fasullo [2]).
A sufficiently accurate data set available for the time period subsequent to 2001–2002 now exists. There are two different observational systems for determining OHC. The first and older is based upon expendable bathythermograph (XBT) probes that have been shown to have various biases and systematic errors (Wijffels et al. [3]). The second is the more accurate and complete global array of autonomous Argo floats [4], which were deployed as of the early 2000s. These floats are free from the biases and errors of the XBT probes although they have had other systematic errors [5]. We begin our analysis with the more accurate Argo OHC data. There are issues associated with a “short-time”
segment of data, which are addressed.
2. Data and Analysis
In what follows, we make reference to FOHC, defined as the rate of change of OHC divided by Earth’s area. It has units of energy flux and is therefore convenient when discussing heating of the whole climate system. In W/m2, FOHC is given by 0.62d(OHC)/dt when the rate of change of OHC is presented in units of 1022 J/yr.
Figure 1 shows OHC data from July 2003 through June 2008 (blue data points, left scale) as obtained from Willis [6]. These data appear to show a negative trend (slope) but there is an obvious annual variation that must be “removed.” We estimated the trend in four different ways, all of which reduce the annual effect. Method 1. The data were put through a 12-month symmetric box filter (Figure 1, red curve). Note that the length of the time segment is four years. The slope through these data, including standard error, is –0.260 ± 0.064 × 1022 J/yr, or FOHC = –0.161 ± 0.040 W/m2.
Method 2. The difference between the OHC value for July 2007 and July 2003 is divided by 4, giving one annual slope estimate. Next, the difference between
August 2007 and August 2003 is calculated. This is done ten more times, the last difference being June 2008 minus June 2004. The average slope of these twelve values, including standard deviation, is –0.0166 ± 0.4122 × 1022 J/year, or FOHC = –0.0103 ± 0.2445 W/m2. Method 2’s advantage is that the difference of four years is free
from short-term correlations.
Method 3. Slopes of all January values were computed and this was repeated for each of the other months. The average of the twelve estimates, including standard deviation, is –0.066 ± 0.320 × 1022 J/year, or FOHC = –0.041 ± 0.198 W/m2.
Method 4. The average of OHC for the 12 months from July 2003 to June 2004 was computed, similarly for July 2004 to June 2005, etc. For the five values the slope found, including standard error, is –0.0654 ± 0.240 × 1022 J/yr, or FOHC = –0.0405 ± 0.1488 W/m2.
These results are listed in Table 1.
There have been four other recent estimates of slopes from the Argo OHC data, by Pielke [7], Loehle [8], Douglass and Knox [9], and von Schuckmann et al. [10]. Each of these studies of Argo OHC data with the exception of von Schuckmann’s, which differs in the ocean depth covered (0–2000 m), show a negative trend with an uncertainty of several 0.1 W/m2. Why the von Schuckmann case is an “outlier” is worthy of further study.
…
3. Discussion and Summary
As many authors have noted, knowing FOHC is important because of its close relationship to FTOA, the net inward radiative flux at the top of the atmosphere. Wetherald et al. [13] and Hansen et al. [14] believe that this radiative imbalance in Earth’s climate system is positive, amounting recently [14] to approximately 0.9 W/m2. Pielke [15] has pointed out that at least 90% of the variable heat content of Earth resides in the upper ocean.
Thus, to a good approximation, FOHC may be employed to infer the magnitude of FTOA, and the positive radiation imbalance should be directly reflected in FOHC (when
adjusted for geothermal flux [9]; see Table 1 caption). The principal approximations involved in using this equality, which include the neglect of heat transfers to land masses and those associated with the melting and freezing of ice, estimated to be of the order of 0.04 W/m2 [14], have been discussed by the present authors [9].
In steady state, the state of radiative balance, both quantities FTOA and FOHC should be zero. If FTOA > FOHC, “missing energy” is being produced if no sink other than the ocean can be identified. We note that one recent deep-ocean analysis [16], based on a variety
of time periods generally in the 1990s and 2000s, suggests that the deeper ocean contributes on the order of 0.09 W/m2. This is not sufficient to explain the discrepancy.
Trenberth and Fasullo (TF) [2] believe that missing energy has been accumulating at a considerable rate since 2005. According to their rough graph, as of 2010 the missing energy production rate is about 1.0 W/m2, which represents the difference between FTOA ~ 1.4 and FOHC ~ 0.4 W/m2. It is clear that the TF missing-energy problem is made much more severe if FOHC is negative or even zero. In our opinion, the missing energy problem is probably caused by a serious overestimate by TF of FTOA, which, they state, is most accurately determined by modeling.
In summary, we find that estimates of the recent (2003–2008) OHC rates of change are preponderantly negative. This does not support the existence of either a large positive radiative imbalance or a “missing energy.”
===============================================================
Read the full paper available here at the authors University of Rcohester website:
http://www.pas.rochester.edu/~douglass/papers/KD_InPress_final.pdf
For those wondering how ARGO works unattended, this image shows how:
Simple Mission Operation: The float descends to cruising depth, drifts for several days, ascends while taking salinity and temperature profiles, and then transmits data to satellites. More here
h/t to Russ Steele
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Before Argo, was there ANY longterm reliable widespread data down to 2000M?
There is a difference between explaining something and explaining away something. To say that there is no missing ocean heat found so far explains something. Claiming that the missing heat must therefore be someplace else is an attempt at explaining away an unwelcome observation. Attempting to dismiss a fact by contriving an ad hoc speculation or untested hypothesis is what one expects from those suffering from cognitive dissonance.
The recent epidemic of cognitive dissonance amongst warmists is wonderful to behold. They make themselves look both desperate and foolish as they flounder about in search of ways to explain away the current cooling trend. In so doing they will ultimately destroy what little is left of their credibility.
Measurements of ocean heat content (OHC) down to 700 m show cooling. But one measurement down to 2000 m (about half way down to the average ocean bottom depth of 4000m) shows warming (averaged over all depths 0-2000m).
When you think this through it makes good sense.
The upper ocean is clearly cooling [refs. 6, 7, 8, 9]. Where is the heat going? The amount of heat in the ocean is – as often repeated here on WUWT – many hundreds of times more than in the atmosphere.
It is impossible for all this heat to be removed just at the surface by interaction with atmosphere and ocean. The atmosphere has a tiny fraction of the ocean’s heat capacity. Even emission to space – at rates within the satellite-measured range by IR etc. – over a single decade cannot account for this flux of heat.
The only other option for this real “missing heat” is – as Trenberth correctly concludes – the deep ocean. But the missing heat is associated with cooling, not warming.
Deep ocean water is colder than surface water. The only mechanism by which the upper ocean (down to several hundred meters, not just SST) can be cooled is water convection by upwelling – the upward movement of substantial volumes of deep cold water, such as occurs at the East Pacific in the La Nina cycle and most of the time except during an el Nino.
If deep water moves up in one place, it must be replaced by upper water downwelling somewhere else. Thus upwelling must be balanced (somewhere) by downwelling.
Thus:
(1) cooling upper ocean means upwelling (nothing else can shift that amount of heat that quickly)
(2) upwelling means downwelling
(3) upwelling + downwelling means increased mixing of the whole water column, which has the inevitable result of
(4) warming of deep cold ocean water – probably mostly around the middle of the water column, i.e. about 2000m down.
Cooling of the upper ocean results in cooling climate. If climate cools it is because of cooling upper ocean.
The upper ocean (as distinct from just SST) can only by effectively cooled by upwelling and deep mixing.
Thus, in an analogous way to which AGWers posit a cooling stratosphere to accompany troposphere warming, climate cooling due to cooling of the upper ocean must result in an increase in ocean temperature at mid water column depths e.g. 2000m.
Thus in conclusion, Von Schuckmann’s finding of apparent warming at depths down to 2000m, in combination with multiple observations of cooling in the upper 700m, is important confirmation of upper ocean cooling and consequent climate cooling.
Heat is “missing” only in the minds of modellers. Now, what those minds and models are missing is the operative question.
Unless geothermal sources on the ocean bottom are much greater than is commonly known, the abyssal waters are kept near 3C primarily by very inefficient conduction from layers intermediate between the well-mixed near-surface layer. THC does not generally reach that deep. While upwelling on continental shelves may bring cold bottom-water to the surface, this never happens in the deep ocean. By comparison to the upper layers, the deeper layers that are assumed to be the heat sink are very poorly measured. There simply is no sound basis for saying whether they have cooled or warmed. In either event, their impact upon surface climate is negligible. And their temperature, which transitions gradually between that of seasonal thermoclines and the abyss is invariably much higher than in the upper troposphere, let alone space. Entropy tells us in which direction the “missing” heat escaped., if it was there at all.
There’s a lot of speculation going on on this thread, and much of it is not supported by OHC data. The Knox and Douglass paper ended its data in 2008, and since that time, OHC has risen globally. The rise isn’t significant but it is a rise, and all of those attempting to explain why OHC is dropping should refer to the most up-to-date OHC based on ARGO data:
http://bobtisdale.blogspot.com/2010/10/update-and-changes-to-nodc-ocean-heat.html
The OHC data since 1955 reveals that the dominant drivers of OHC are natural and they are ENSO, Sea Level Pressure in the form of the AO and NPI, and AMOC. This was discussed in three posts (and if memory serves me well, they were cross posted here at WUWT). Refer to:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
And:
http://bobtisdale.blogspot.com/2009/12/north-pacific-ocean-heat-content-shift.html
And:
http://bobtisdale.blogspot.com/2009/10/north-atlantic-ocean-heat-content-0-700.html
sky says:
January 7, 2011 at 12:46 pm
Bob Tisdale says:
January 7, 2011 at 2:44 pm
There’s a lot of speculation going on on this thread, and much of it is not supported by OHC data. The Knox and Douglass paper ended its data in 2008, and since that time, OHC has risen globally. The rise isn’t significant but it is a rise, and all of those attempting to explain why OHC is dropping should refer to the most up-to-date OHC based on ARGO data:
http://bobtisdale.blogspot.com/2010/10/update-and-changes-to-nodc-ocean-heat.html
The OHC data since 1955 reveals that the dominant drivers of OHC are natural and they are ENSO, Sea Level Pressure in the form of the AO and NPI, and AMOC…
Bob, the recent (post-2008) OHC rise is presumably linked to the latest el Nino, now being reversed by the current La Nina. Looking at all your OHC charts, this uptick is indeed of little significance, not really affecting an overall downward current trend globally.
The point I raised previously is admittedly not backed up by hard facts and figures, but based on the (IMO reasonable) premise that, such is the magnitude of the heat content of the ocean – we are talking about hundreds of meter layers, not the millimeter or two that account for SST – that significant changes of heat content in the upper thousand or so meters of ocean cannot be ascribed to a few weeks of sun or cloudiness or wind. The overall heat balance at the surface is approximately known and does not allow for the huge changes in flux that wound be needed to change the temperature of the upper thousand meters at the rates at which such changes are observed (or would they??).
Of course weather at the ocean surface matters, every photon absorbed and every evaporated water molecule change OHC. And SST can react practically in real time to weather (sun and no wind = instant high SST). Its just a question of scale and the amount of energy. I am suggesting vertical mixing and upwelling / downwelling as likely important players in OHC changes. (What controls or “drives” or “forces” up/downwelling changes or cycles is another question entirely). Possibly the dominant players. Unless my very empirical maths is entirely wrong.
The Argos data – from my limited look at some of it – seem to be revealing more thermal structure in the water column than would have been expected. This suggests more vertical mixing than previously assumed. “Sky” above reiterated the standard oceanography position that in the deep ocean the water column is very poorly mixed or even – at the bottom – completely unmixed and stratified. At Abyssal depths this is likely true. The mixing I was speculating about involved approximately the middle of the water column, not the very bottom.
The water column is, in general and as a whole, strongly stratified; vertical mixing modifies this stratification in only a minor way. However in view of the sharp drop in temperature with depth that characterises this stratification, any vertical mixing represents downward movement of heat, and consequent cooling of the surface layer. Thus vertical mixing – integrated over whole oceans or globally – can by itself be a major climate player.
The AGW people are looking to deep ocean heat as a possible refuge for beleagured global warming missing heat. But this is just one paradigm – an alternative one is that “deep heat” is a signature of vertical mixing, which is a signature of surface layer cooling – a fore-runner of climate cooling.
I’m sure you’ll shoot me down in flames – but what the heck!
From this data I would conclude there is either no trend in ocean heat content or a very small negative trend. The only thing definitely ruled out is a warming trend.
Of course, this is more significant than anything going on in the atmosphere. Water holds much more heat than air (which is why we use hot water bottles, not hot air bottles) to help keep us warm.
This simply confirms what I’ve been telling anyone who will listen (no one): the world is cooling.
phlogiston (January 7, 2011 at 4:18 pm): Eventually, someone will put together 3D animations based on the ARGO data.
“Jack Simmons says:
January 7, 2011 at 8:38 pm
Water holds much more heat than air (which is why we use hot water bottles, not hot air bottles) to help keep us warm.”
Indeed:
http://climaterealists.com/index.php?id=1487&linkbox=true&position=4
“The Hot Water Bottle Effect.”
“This paper only confirms that somehow the heat is transferred to the Deep Ocean by downwelling currents, like the Atlantic Meridional Overturning Current (AMOC).”
The heat? Would that be as modeled so accurately by Trenberth and Fasullo? We should go and check out Gigo Inc for the latest figures.
Feel the heat. Monbiot wrote a book about it. Unfortunately he didn’t have anything scientific to say on ‘somehow’. Something to do with redistribution of heat being linked to redistribution of wealth maybe.
If the “missing heat” can’t be found from the surface down to a depth of 700 meters, I find it very difficult ( in fact, almost impossible ) to believe that such a large quantity of heat could be hiding in deeper water.
Jimbo says:
January 7, 2011 at 2:51 am
It seems that the exits are closing one by one. Just when the Warmists will admit defeat is anyone’s guess but our best friend is a cooling planet over time as AGW would find itself in a right pickle
________
Let’s see Jimbo…2010 was in the top 1 or 2 warmest years on instrument record, and the Arctic has not seen a positive sea ice anomaly since 2004. 2000-2009 was the warmest decade on record, Antarctic and Greenland ice mass continues to decline, and the oceans continue to rise through both additional water from melting ice as well as thermal expansion. Why, exactly, would “warmists” want to “admit defeat?”.
It seems this period of a quiet sun has given the AGW skeptics a bit too much puffery…
John W. Garrett says:
January 8, 2011 at 9:55 am
If the “missing heat” can’t be found from the surface down to a depth of 700 meters, I find it very difficult ( in fact, almost impossible ) to believe that such a large quantity of heat could be hiding in deeper water.
____
Perhaps you ought to do a bit more research on the topic, beginning here:
http://news.discovery.com/earth/antarctica-melting-warming-penguins-101214.html
R. Gates says:
January 8, 2011 at 11:21 am
Perhaps you ought to do a bit more research…
______________
QUOTE:
Accounting for the known contributions to energy uptake still leaves a likely residual of 30–100× 10^20 J/yr, although total error bars overlap. Possibly this heat is being sequestered in the deep ocean below the 900 m depth used for the ARGO analyses where it would contribute about 0.4–0.5 mm/yr sea level rise, and then the land ice melt estimate would have to go down. Or the warming is not really present?
http://www.cgd.ucar.edu/cas/Trenberth/trenberth.papers/EnergyDiagnostics09final2.pdf
http://pielkeclimatesci.wordpress.com/2010/04/16/is-there-missing-heat-in-the-climate-system-my-comments-on-this-ncar-press-release/
QUOTE:
Trenberth replied… that von Schuckmann’s energy imbalance of 0.77 W/m2 was for the ocean only and when you average it out over the whole globe, it gives a net energy imbalance of 0.54 W/m2. This is still insufficient to meet up with the satellite data and there are unresolved issues …
http://www.skepticalscience.com/Tracking-the-energy-from-global-warming.html
“2010 was in the top 1 or 2 warmest years on instrument record, and the Arctic has not seen a positive sea ice anomaly since 2004. 2000-2009 was the warmest decade on record, Antarctic and Greenland ice mass continues to decline, and the oceans continue to rise through both additional water from melting ice as well as thermal expansion.”
Let’s see Gater: Norway and Finland are having exceptionally cold weather because the AO is retrograde and Greenland/Labrador ice is being flushed into Arctic by the ‘warm’ NA waters. Sea of Othotsk is receiving sea ice flushed from Arctic locking 10 freighters in ice.
Warm tropopause temps coincide with elevated cloudiness and H2O, a significant greenhouse gas, and a source of negative feedback responsible in large part for the ‘missing heat’ as the albedo began its rise at the end of the last millenium.
GISS interpolation of Arctic warming is entirely fraudulent. Finally, the record is corrupt, having been incrementally adjusted upward for a decade.
Back-radiation cannot heat the oceans because the emissivity of water and snow is 500 times the preponderant low-pressure green house gasses.
It is your pompous self that requires remediation.
phlogiston says:
January 7, 2011 at 11:43 am
Your notion of strong downward mixing in the intermediate levels (say,1000-3000m)of the deep ocean has precious little observational basis. It seems to rest on a mistaken sense of the rate at which the recently-much-ballyhood THC operates. Compared to wind-mixing, the breaking of internal waves near the seasonal thermocline, and the intrusion at depth by ever-shifting current regimes, that rate of heat transport is very minor. We should be aware of order of magnitude differences!
Looking at global OHC is fine idea in principle, but in practice we need the temporal difference in very huge numbers that are, at best, very crudely estimated spatially and temporally prior to the advent of ARGO. Even ARGO, which has nary a station in the Caribbean, does not provide a definitive picture.
There’s nothing shameful in saying “we don’t really know.” But that’s not the meme in climate science, where pet theories seem to flourish in a scientific desert.
‘Trenberth replied… that von Schuckmann’s energy imbalance of 0.77 W/m2 was for the ocean only and when you average it out over the whole globe, it gives a net energy imbalance of 0.54 W/m2. This is still insufficient to meet up with the satellite data and there are unresolved issues …
http://www.skepticalscience.com/Tracking-the-energy-from-global-warming.html‘
John Cook at ScepSci used the Harries paper and offshoots to show a change in IR emissions over the satellite era – the so called missing heat. I think the Harries paper is quite clever in demonstrating the obvious – a change in IR emissions as a result of a build up of greenhouse gases in the atmosphere. But Cook is typically ingenuous in ignoring the change in total radiative fluxes.
Someone mentioned that the satellite data was not precise enough to define absolute radiation and this is true enough – but it is the change we are interested in – which is considerably more precise and can be used to quantify change in energy storage in the atmosphere and oceans.
Consider the 1st order differential equation of global energy storage (GES).
EIN/S = EOUT/S + d(GES)/dt (1)
By the law of conservation of energy – the average energy in at the top of atmosphere (TOA) in a period is equal to the average energy out plus the rate of change in global energy storage. Energy in (in the visible and infrared spectrum) varies marginally in the 11 year Schwabe solar cycle, perhaps a little more over the longer term due to solar variation and, due to orbital changes, over an Ice Age. On a decadal timescale – energy in is more or less constant.
Most change in the global energy balance occurs in energy out resulting in an equal and opposite change to global energy storage – planetary heating and cooling. Energy out is measured by satellite in the short wave and infrared spectrums. Changing cloud cover influences the global energy balance by reflecting more or less visible light back into space – and thereby reducing or increasing the amount of energy coming into Earth’s climate system. As stated above, greenhouse gases change radiative flux in the infrared band. In both cases, the change in radiative flux is reflected in a change in energy stored in the Earth’s climate system – mostly as heat in the oceans. If the trend in energy out in a period is negative then the rate of change of global energy storage is positive and the planet warms and vice versa.
There is a discussion by Roy Spencer here –
http://www.drroyspencer.com/2009/09/the-2007-2008-global-cooling-event-evidence-for-clouds-as-the-cause/ – showing the CERES data.
The big changes are in the shortwave – decreasing reflectance over the period of record to 2008 along with fluctuation but no trend in IR. The shortwave changes (and most of the IR changes) are a result of cloud cover changes in the period.
There are many complexities involving ENSO and cloud feedback and other factors – but the bottom line is that the planet should have warmed in the period and this is why the von Schuckmann paper better reflects what should be the empirical reality. The planet has warmed over the past decade but, as always, this has most to do with ENSO variability.
To quote Roy: ‘I was especially interested to see if this was caused by a natural increase in low clouds reducing the amount of sunlight absorbed by the climate system. As readers of my blog know, I believe that most climate change – including “global warming” – in the last 100 years or more has been caused by natural changes in low cloud cover, which in turn have been caused by natural, chaotic fluctuations in global circulation patterns in the atmosphere-ocean system. The leading candidate for this, in my opinion, is the Pacific Decadal Oscillation…possibly augmented by more frequent El Nino activity in the last 30 years.’
‘Tropical and subtropical low-level marine clouds consist of optically thick stratocumulus clouds, which usually form over the regions associated with relatively cold sea surface temperatures (SST) and atmospheric subsidence, and optically thin shallow cumuli in the tradewind regime. These low-level clouds play a pivotal role in the global climate system not only by affecting radiative budgets but also by promoting heat and moisture exchange between the sea-surface, the boundary layer, and the overlying troposphere.’ (Zhu, P., Hack, J., Keilh, J and Zhu, P, Bretherton, C. 2007, Climate sensitivity of tropical and subtropical marine low cloud amount to ENSO and global warming due to doubled CO2 – JGR, VOL. 112, 2007)
The big changes in SST, and therefore clouds in the climatological critical tropical and sub-tropical regions is of course ENSO and ENSO is of course a complex and dynamic system (chaotic – have a look at the 2007 and 2009 papers from Tsonis and colleagues). The ‘oscillation’ (more correctly a chaotic bifurcation) is non-stationary and non-Gaussian – producing climate change over decades to millennia.
Cheers
Robert
You know, the more I think about it, the more the idea of ‘smoothing’ out those seasonal wanderings bothers me.
Here we have clear evidence that the ocean can gain, or dump, a pot load of heat (ocean mass x specific heat x 1 C range – from the looks of the graph) in VERY short order. Any “retained” heat would be dumped in a couple of months, per the slope of those seasonal rise / fall segments.
What this tells me is that the system is not acting as a slow charging battery, it’s acting like a very fast capacitor. It only gains temperature (and thus heat as mass and specific heat are nearly constant for the ocean) when the input is in excess, and promptly dumps it when the input is in deficit.
Those cycles tell you that the whole notion of ‘retained excess heat’ is broken. All you have is a fast read of input variation. And from the looks of it, that variation is closely tracking the sun. Both seasonally as it has more ‘sun on the ocean’ and over the years as the sun has cooled down from the 1998 or so peak.
Basically, I think there is a whole lot of ‘over averaging’ in this ocean retained heat business and it’s hiding the actual mechanism of rapid heat gain / loss in sync with input variation.
All you buoys are belong to us. 😉
{R. Gates says:
January 7, 2011 at 7:45 am
Some additional points to ponder related to this “research” paper:
1. Do the authors describe what data they use, exactly? Argo data have undergone
several major revisions.
2. Data varies in time in amount and coverage, and some floats were “bad” and some had calibration problems (the surface pressure was recorded as negative, indicating depth problems).
3. Why don’t the authors use Lyman et al results?
4. Looking at the figure in the paper also reveals a clear problem: The values at the end are higher than any others yet they have a downward trend. Clearly any “trend” they get depends critically on how they get it and it highly dependent on the time period. By taking a 12 month running mean they discount the last 6 months.}
Mr Gates, you describe these questions, over at Dr. Curry’s blog, as coming from Dr. Trenbeth, from an e-mail exchange with the good Dr.
If you check the latest posts on Climate Etc. You will see that Drs. Douglass and Knox have now replied to your/Dr. Tenbreth’s questions.
http://judithcurry.com/2011/01/07/wheres-the-missing-heat/
sky says:
January 8, 2011 at 2:23 pm
phlogiston says:
January 7, 2011 at 11:43 am
Your notion of strong downward mixing in the intermediate levels (say,1000-3000m)of the deep ocean has precious little observational basis. It seems to rest on a mistaken sense of the rate at which the recently-much-ballyhood THC operates. Compared to wind-mixing, the breaking of internal waves near the seasonal thermocline, and the intrusion at depth by ever-shifting current regimes, that rate of heat transport is very minor. We should be aware of order of magnitude differences!
Looking at global OHC is fine idea in principle, but in practice we need the temporal difference in very huge numbers that are, at best, very crudely estimated spatially and temporally prior to the advent of ARGO. Even ARGO, which has nary a station in the Caribbean, does not provide a definitive picture.
There’s nothing shameful in saying “we don’t really know.” But that’s not the meme in climate science, where pet theories seem to flourish in a scientific desert.
“Strong” downward mixing is putting it too … well … strongly. I’m not proposing any detailed mechanism of ocean circulation and dynamics – that’s been done already, starting with the Pacific, by Bob Tisdale, focusing on the ENSO system.
What I’m saying amounts to armchair oceanography, thinking aloud about the role of vertical mixing in the context of a generalised global ocean heat budget. The starting point is the set of Argos studies reported on this posting by Knox and Douglass – 4 showing cooling in the upper 700m, 1 (Von Schuckmann or “VS”) showing warming down to 2000m, over the last half-decade. You and others have pointed to the uncertainty in these findings – 3256 floats is still too few for the world’s oceans, and the density of measurement decreases with depth. At the deepest layers, the smallest number of measurements is multiplied by the largest heat capacity to give the greatest errors. So the only very general conclusion I would draw is that (1) the surface 700m seems to be cooling and (2) if you look deeper the temperature trend moves in a positive direction – warming or less cooling.
I considered the question of what happens to the very large amount of energy moved by a change in temperature of a significant slice of the ocean in half a decade – if the upper 700m has cooled, where has the energy gone? Its a nonsense to suggest the atmosphere (1/500 of the ocean heat capacity), and radiation of all this energy to space would surely give a substantial outgoing IR signal that would have been noticed. The only other possibility is vertical ocean mixing pulling the heat down. I reflected on the fact that in a strongly stratified ocean, with temperature falling sharply with depth, ANY vertical mixing results in downward movement of heat.
The ocean mixing processes that you mention are interesting – “wind-mixing, the breaking of internal waves near the seasonal thermocline, and the intrusion at depth by ever-shifting current regimes. You assert that this mixing is too small in magnitude to have the significance that I am arguing / suggesting. However (admittedly anecdotal) indications from Argos data are that pockets of warmer water appear quite deep down and vertical mixing may be more significant than previously thought – perhaps some of the mechanisms you refer to might be more powerful than presently understood, or other mechanisms may exist.
In the Pacific ocean ENSO system, what I am saying (that vertical mixing explains a lot of the heat movement) is orthodox, not controversial – La Nina cools the (eastern) Pacific surface by substantial deep upwelling, and this leads to an episode of climate cooling. Conversely, el Nino systems interrupt this upwelling, which combined with decreased trade winds results in a large warm pool of surface Pacific water, and and episode of climate warming. (Back me up here Bob if you’re still following this thread – although I’m probably just talking to myself here.) My argument is simply to extend this generic process to to the global ocean, and suggest that the main driver in OHC of the upper level ocean might be vertical mixing – this umbrella term could include many mechanisms, anything moving deep water up and surface water down.
I very much agree with your point that we know little about the working of climate as a whole – what causes the whole fractal range of climate oscillation from hot and cold years to PDO oscillations, MWP-LIA swings and switching between glacial and interglacial, is largely unknown, only fragmentary clues and speculations are explored. In the coming years the extent of our ignorance of climate will move more clearly into focus. Eventually some underlying and unifying explanatory theories / mechanisms might be found. If I’m lucky I might be alive to see it.
phlogiston:
Armchair oceanography is not a science, but a realm of speculation–one that runs into deep conflict with observations. I don’t wish to spend time on that, other than pointing out the most egregious lapses. The whole idea that there is heat “missing” is model-based conjecture. I never suggested that this conjectural heat is being actually STORED in atmosphere, only that entropy favors that escape route to space, rather than storage in the deeper levels of the oceans. Nor am I saying that the “interesting” mechanisms of downward transport of heat from the sun-warmed layer are too weak. Measurements indicate that they simply do not penetrate to the deep levels that you’re speculating about. Downwelling as a necessary adjunct to upwelling–which is confined to continental shelves and margins–is untenable when one considers the wind-stress induced dynamic topography. As for the “detailed mechanisms of ocean circulation and dynamics,” I’m unaware of any ground-breaking proposals by Bob Tisdale that are based on rigorous dynamical analysis. If you’re seriously interested in the science, let me recommend Piccard’s “Introduction to Dynamic Oceanography” for starters.
Dave Wendt says:
January 6, 2011 at 7:03 pm
“The flow at the ocean’s bottom is generally poleward not away from the poles and introduces a not entirely insignificant amount of heat from geothermal sources, particularly into the AABW”
Nonsense. The conveyor belt generally carries warm surface water from the tropics poleward where it cools, sinks, and returns along the bottom.
http://oceanservice.noaa.gov/facts/conveyor.html
I found the missing heat. It’s spread out in an expanding sphere with a radius of about 30 light years.
All that cool water extending virtually Indonesia is experiencing some cloud cover. EUV retarded at source and visible retarded near surface are integrating at reduced levels. Look for neutral conditions following La Nina, whenever it comes.