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Lindzen Illusion #5: Internal Variability

Posted on 8 May 2011 by dana1981

In a recent media article which was uncritically re-posted at a number of websites like "skeptic" blog WattsUpWithThat, in amongst many other erroneous statements, Richard Lindzen attempted to blame global warming on natural internal variability (emphasis added):

"For small changes in climate associated with tenths of a degree, there is no need for any external cause. The earth is never exactly in equilibrium. The motions of the massive oceans where heat is moved between deep layers and the surface provides variability on time scales from years to centuries."

Achilles Heel for Internal Variability

In the quote above, Lindzen has unwittingly revealed the Achilles heel of the 'internal variability' argument.  Internal variability means that heat is just being moved around from one part of the Earth's climate system from another, i.e. in Lindzen's example, from the deep ocean layers to the surface.  But if the movement of heat from the deep oceans is what's causing the surface air to warm, this hypothesis requires that the oceans as a whole and deep ocean layers in particular must be cooling.

In reality, that's not happening.  We know that the upper 2,000 meters of the oceans exhibit a long-term accumulation of heat (Figure 1).


Figure 1: Changing heat content of the global ocean, with respect to the mean of 1993 to 2008 (Trenberth 2010). This analysis samples the ocean to 700 m depth and gives an average warming trend of 0.64 W m−2 (pink line). The data available from Argo floats since 2003 enable an estimate to 2,000 m depth (blue line).

And Purkey & Johnson (2010) reconstructed ocean heat accumulation down to abyssal depths and found significant amounts of heat building up even at the bottom of the ocean (Figure 2).

Figure 2: Rate of ocean warming. Areas of warming are shaded in red and regions of cooling are shaded in blue with intensity scaled by the magnitude of the warming. The basins from south to north are the Southeast Pacific Basin, Chile Basin, Peru Basin, and Pacific Basin (Purkey & Johnson 2010).

There are several other indicators of building ocean heat. Satellites observing incoming and outgoing radiation are able to measure changes in the planet's energy imbalance from year to year. What they find is the planet's energy imbalance continues to increase (Trenberth & Fasullo 2010, Hansen et al. 2011).  And sea levels continue to rise, largely due to thermal expansion as a result of the warming oceans.

Clearly this warming of the entire global climate system must be caused by an external forcing, and the radiative forcings over the past century have been dominated by greenhouse gases.  Lindzen's internal variability argument just doesn't hold up in the face of the observational data and physical reality.  Unfortunately, in the aforementioned article, Lindzen proceeds to attempt to defend this indefensible argument by misrepresenting the work of a number of other climate scientists.

Tsonis et al. 2007

Lindzen first makes the following claim about the work of Tsonis and colleagues:

"Recent work (Tsonis et al, 2007), suggests that this variability is enough to account for all climate change since the 19th Century."

This statement is quite different from the actual conclusions of Tsonis et al. (2007) (emphasis added):

"The standard explanation for the post 1970s warming is that the radiative effect of greenhouse gases overcame shortwave reflection effects due to aerosols [Mann and Emanuel, 2006]. However, comparison of the 2035 event in the 21st century simulation and the 1910s event in the observations with this event, suggests an alternative hypothesis, namely that the climate shifted after the 1970s event to a different state of a warmer climate, which may be superimposed on an anthropogenic warming trend."

Nowhere in their paper do Tsonis et al. claim that natural variability can account for the entire warming trend over the past century.  Tsonis was also a co-author on a more recent paper,  Swanson et al. (2009) which John has previously discussed

Swanson and Tsonis 2009 was a similar study exploring the role of natural variability in global temperatures, and as with Lindzen's treatment of Tsonis' 2007 paper, it was widely misrepresented, as Dr. Swanson noted:

"What do our results have to do with Global Warming, i.e., the century-scale response to greenhouse gas emissions? VERY LITTLE, contrary to claims that others have made on our behalf. Nature (with hopefully some constructive input from humans) will decide the global warming question based upon climate sensitivity, net radiative forcing, and oceanic storage of heat, not on the type of multi-decadal time scale variability we are discussing here. However, this apparent impulsive behavior explicitly highlights the fact that humanity is poking a complex, nonlinear system with GHG forcing – and that there are no guarantees to how the climate may respond."

In their paper, Swanson and Tsonis use climate models to hash out the role internal variability has played in average global temperature changes over the past century (Figure 3). 

Swanson Tsonis variability

Figure 3: Estimation of the observed signature of internal variability in the observed 20th century global mean temperature in climate model simulations

As you can see, over periods of a few decades, modeled internal variability does not cause surface temperatures to change by more than 0.3°C, and over the entire 20th Century, its transient warming and cooling influences tend to average out, and internal variability does not cause a long-term temperature trend.

Smith et al. 2007

Lindzen's article proceeds with an even worse misrepresentation of Smith et al. 2007 (emphasis added):

"scientists at the UK’s Hadley Centre for Climate Research recently noted that their model did not appropriately deal with natural internal variability thus demolishing the basis for the IPCC’s iconic attribution (Smith et al, 2007). Interestingly (though not unexpectedly), the British paper did not stress this. Rather, they speculated that natural internal variability might step aside in 2009, allowing warming to resume."

So according to Lindzen, Smith et al. (2007) "demolishes the basis" for attributing global warming over the past century to anthropogenic influences.  I'm sure this interpretation of their work would come as a shock to the authors, who conclude as follows:

"We present a new modeling system that predicts both internal variability and externally forced changes and hence forecasts surface temperature with substantially improved skill throughout a decade, both globally and in many regions. Our system predicts that internal variability will partially offset the anthropogenic global warming signal for the next few years....Both NoAssim and DePreSys, however, predict further warming during the coming decade, with the year 2014 predicted to be 0.30° ± 0.21°C [5 to 95% confidence interval (CI)] warmer than the observed value for 2004. Furthermore, at least half of the years after 2009 are predicted to be warmer than 1998, the warmest year currently on record."

DePreSys is a dynamical climate model which takes into account the observed state of the atmosphere and ocean in order to predict internal variability, while NoAssim is identical to DePreSys, but does not assimilate the observed state of the atmosphere or ocean or predict internal variability.  Smith et al. used these models to compare the accuracy of the model global temperature hindcasts back to 1982 (Figure 4).

Smith et al Fig 2A

Figure 4:  Smith et al. (2007) temperature hindcasts for the DePreSys model (red, accounting for internal variability) and NoAssim (blue, no  internal variability)

As you can see, the DePreSys model (which accounts for internal variability) matches the short-term temperature changes significantly better than the NoAssim model.  However, both models produce the same warming trend.  So how does Lindzen conclude that this paper "demolishes the basis" for man-made global warming when accounting for natural variability does not change the warming trend?  Your guess is as good as mine, but it's clearly a gross misrepresentation of the results of the study.

Wrong for Two Decades, Again

As with many of Lindzen's arguments, he's been making this one for a long time.  In his 1989 MIT Tech Talk, Lindzen similarly argued that global warming boiled down to little more than internal variability.

"What we have is data that says that maybe [warming] occurs, but it's within the noise....The point we have to keep in mind is that without any of this at all our climate would wander--at least within limits."

However, as we've shown in this post, contrary to Lindzen's claims, internal variability simply cannot account for the warming over the past century.  The magnitude of the observed warming is too large, and the fact that the entire climate system is warming tells us that an external forcing is at work.  Perhaps most disturbing is Lindzen's misrepresentation of other climate scientists' work in defending his fundamentally flawed argument.

Bottom line, as convenient as it would be, it's not internal variability!

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Comments 101 to 132 out of 132:

  1. Chris #97

    You are not arguing on the numbers Chris.

    "There is some good evidence that the mass component of sea level rise has increased somewhat in proportion to the thermal component during part of this period. But all analyses of the latter indicate that thermal component of sea level rise has continued to be positive."

    It would need to be positive because if not there is no steric expansion at all and no temperature rise in the oceans.

    You know that mass increase from land ice melt absorbs only about 4E20 Joules/year which is equal to 0.025W/sq.m globally compared with 0.9W/sq.m prior imbalance.

    "And why didn’t K/D cite Willis’s data in Lyman 2010? The VS result wouldn’t have been an outlier anymore"

    Why indeed? All the Argo analyses show flattening from 2003 onward, and VS happens at 0.54W/sq.m globally to be the highest of these.

    Has Willis rejected the K&D treatment of his data for 0-700m obtained in reference (6) in that paper?

    It seems like Willis is rather generous with his data in handing it to K&D and perhaps Dr Pielke to see what you claim is - 'misuse'.

    "dismal, butchered, atrocious scholarship" - not exactly arguing the numbers Chris.

    I am not carrying a torch for K&D or anybody else. I am quoting analyses which you are free to criticize on the numbers - not emotive catcalling.
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  2. Ken @101,

    Many keepers there, but this one really stood out.

    "not emotive catcalling.'
    Pot meet kettle.

    And yes, you misrepresented Dyson @95. Qu'elle surprise. And you have still avoided answering my question at 93 :)

    And, you seem to be blissfully unaware of the huge difference in measuring OHC in the top 700 m versus the top 1500-2000 m. Please stop confusing the two.

    Yet again, please remind me what you arguing here has to do with Lindzen's claim that:

    "What we have is data that says that maybe [warming] occurs, but it's within the noise....The point we have to keep in mind is that without any of this at all our climate would wander--at least within limits."

    You know, the subject that Dana spoke to. Otherwise Ken, you seem to be here for the sole purpose of arguing for the sake of arguing.
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  3. Ken Lambert at 00:12 AM on 17 May, 2011

    Well Ken, there's a huge set of data that bears on our knowledge of any particular element of the climate system. It's astonishing to me that someone would focus on truly deficient stuff in junk journals to attempt to reinforce a preferred conclusion. It's not "emotive cat-calling" to call dismal analysis, dismal, and atrocious scholarship, atrocious!

    D/K’s analysis is objectively pretty dismal. I’ve indicated a major problem in my post above. But D/K is additionally a dismal attempt at estimating “Recent Energy Balance of the Earth”. It’s obvious that their energy balance estimation is incorrect. They recognise that vonSchuckmann's analysis is greatly at odds with theirs but can manage only one sentence of "analysis", viz: “Why the von Schuckmann case is an “outlier” is worthy of further study.” That’s simply unacceptable in a scientific paper, if their aim is to provide a sensible estimate of the energy balance. They have to comment on the huge difference. They have to comment on the fact that von Schuckmann’s analysis contains data to the deeper oceans, and they have to comment on the fact that all the evidence for the thermal component of sea level rise indicates that this has remained positive during their study period.

    Otherwise it's a deeply flawed “show and tell”. It doesn’t add to our knowledge or provide insight into the natural world. It’s almost certainly incorrect. It’s atrocious scholarship. I suspect D/K simply don’t care; neither does the International Journal of Geosciences as judged by their acceptance of this in a 10 day received-“reviewed”-revised-accepted process.

    We can surmise that Douglass at least doesn’t care very much since he has a habit of doing this. He butchered an analysis of comparison of model and empirical tropical tropospheric temperature (by using a completely inappropriate statistical analysis), he (with Knox) butchered an analysis of climate sensitivity based on the response to the Pinatubo eruption (by using a completely inappropriate single box representation of the climate system)....You seem a little precious in your aversion to robust descriptors ("atrocious", "dismal", "butchered"), but if one wishes to find out about the world around us, we do need to recognise what is rubbish and what isn't - one may as well be robust about this!

    As for "You are not arguing on the numbers Chris."

    What's the point of "arguing" Ken? The numbers are there in all of the papers we're discussing. The evidence strongly supports the conclusion that the earth is in positive radiative imbalance, whatever the uncertainty in the precise numbers over whatever long or short period of time you wish to "dice" up the analysis. I'm comfortable waiting to see how these subjects develop over the next couple of years. You choose to plant your flag with D/K. As I said above, we're clearly not going to agree over this, so why "argue"?

    Has there been very little ocean heat uptake into the upper 700m of the ocean in recent years? Maybe, maybe not. When we're confident about that we can ask the questions of whether the radiative imbalance has reduced quite a bit for a time or not, and why or why not. You can stick for D/K-style show-and-tell; I'm plumping for the science "in the round"!
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  4. Albatross #102

    RE: Dyson: He definitely does not subscribe to AGW - 'alarmist global warming'.

    "And, you seem to be blissfully unaware of the huge difference in measuring OHC in the top 700 m versus the top 1500-2000 m. Please stop confusing the two."

    Well you can tell us all what is happening between 700m and 2000m. Peer reviewed Argo analysis please.

    "What we have is data that says that maybe [warming] occurs, but it's within the noise....The point we have to keep in mind is that without any of this at all our climate would wander--at least within limits."

    Lindzen maybe, maybe not - right. It depends on how widely the limits of natural variability are drawn.
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  5. Ken Lambert wrote : "RE: Dyson: He definitely does not subscribe to AGW - 'alarmist global warming'"


    I wish you so-called skeptics would try and agree on your terminology or at least (à la Poptech) stop using different versions of terms whenever you feel like it - and without even bothering to tell anyone !

    And do you have your own version of "alarmist" too ? If so, please explain what it means.
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  6. Chris #103

    "He butchered an analysis of comparison of model and empirical tropical tropospheric temperature."

    Here is the conclusion from the butcher busters (Schmidt, Santer, Wigley et al)

    "We may never completely reconcile the divergent
    observational estimates of temperature changes in the
    tropical troposphere. We lack the unimpeachable observational records necessary for this task. The large structural uncertainties in observations hamper our ability to determine how well models simulate the tropospheric temperature changes that actually occurred over the satellite era. A truly definitive answer to this question may be difficult to obtain. Nevertheless, if structural uncertainties in observations and models are fully accounted for, a partial resolution of the long-standing ‘differential warming’ problem has now been achieved. The lessons learned from studying this problem can and should be applied towards the improvement of existing climate monitoring systems, so that future model evaluation studies are less sensitive to observational ambiguity."

    Seems like a pretty equivocal conclusion to me.

    "Has there been very little ocean heat uptake into the upper 700m of the ocean in recent years? Maybe, maybe not. When we're confident about that we can ask the questions of whether the radiative imbalance has reduced quite a bit for a time or not, and why or why not. You can stick for D/K-style show-and-tell; I'm plumping for the science "in the round"!"

    In other words - you don't know until further data is obtained.

    The upshot is that if the radiative imbalance has reduced quite a bit, then cooling forcings are in play which need to be identified, OR the warming forcings are not according to the theory.

    Hansen has a go with extra Aerosols, and the unbelievable 'delayed Pinitubo bounce decay effect'.

    This whole ocean heating story is fascinating.

    We have an open bathtub holding vast amounts of water which is heated from above, the sides and below.

    Above from radiation and air transfer, the sides from ice shelf effects where they occur, and below from geothermal (0.1W/sq.m globally).

    The geothermal effect should be easily eliminated from measurements. A negative 0.1W/sq.m TOA imbalance at equilibrium is required to eliminate this effect, otherwise the biosphere would gain energy indefinitely.

    The top and sides heating need plausible mechanisms for getting heat in and out, down from the top layers to the depths and into the abyss.
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  7. #106 Ken Lambert at 22:08 PM on 17 May, 2011
    This whole ocean heating story is fascinating.

    We have an open bathtub holding vast amounts of water which is heated from above, the sides and below.

    Above from radiation and air transfer, the sides from ice shelf effects where they occur, and below from geothermal (0.1W/sq.m globally).


    Fascinating, indeed. What you are not told often, Ken, is that the deep oceanic circulation (aka thermohaline circulation) is not a heat engine, that is, the mechanical energy needed to push huge water masses around is not derived from entropy (that is, temperature and/or salinity) differences inside the hydrosphere.

    A heat reservoir heated from above in a gravitational field simply can't do that.

    Downwelling of high salinity cold water in subpolar regions could not go on forever, because sooner or later the abyss would get saturated, deep water would be as cold and salty as possible, so no more could go under in any way.

    There should be other processes operating elsewhere that pump heat down and remove salts from deep layers, to make room for more.

    Geothermal heating plays a small part in it (it warms water a bit at the proper level), as short wave solar radiation (light) also does when it penetrates into the water to a depth of several hundred meters.

    But the main player is turbulent mixing, driven by mechanical energy like wind and deep tidal breaking. Most of it is concentrated to small areas along coastlines and mid ocean ridges, where bottom topography is sufficiently rugged. BTW, about 80% of deep turbulent mixing happens in the Southern Ocean, so the true diver of ocean currents is located there.

    Thermohaline downwelling itself does not transfer any heat into the abyss, it removes heat from there.
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  8. Ken Lambert at 22:08 PM on 17 May, 2011

    That’s poor, Ken. You’ve done a little bait and switch.

    The point is that your mate D.H. Douglass butchered an attempt at statistical analysis of comparison of model and empirical data to attempt to draw a false conclusion about the reliability of the models (they wanted to pretend that the empirical data was incompatible with the range of model variability). The laughable nature of their analysis is described in a lecture by Dr. Santer which is worth an hour of anyone’s time – very enlightening and instructive indeed. (if you only want the relevant bit start at around 30 mins in).

    I can see why you love D/K’s style of “research” since it’s a little similar to your researches; i.e. look for areas of uncertainties in sub-disciplines of a subject, assume that the most extreme end of the uncertainty that matches your preconceived idea is the true description of the reality bounded by the variance of the uncertainty (e.g. by putting your faith in D/K's "outputs")…..and then pretend that that calls into question all levels of greater certainty above.

    As your bait-n-switch quote shows, whereas Douglass was determined that the uncertainty could be repackaged to assert that models was incompatible with empirical data on a rather small element of atmospheric response to radiative forcing ( strength of a hotspot), Santer et al are rather more relaxed and honest about the nature of uncertainty.

    This nice paragraph of yours is apposite:

    ” The geothermal effect should be easily eliminated from measurements. A negative 0.1W/sq.m TOA imbalance at equilibrium is required to eliminate this effect, otherwise the biosphere would gain energy indefinitely.”

    I wasn’t going to be too hard on Douglass/Knox but since you brought that up (and them up!), it’s worth mentioning another analysis that D/K butchered. They proposed that the warming in Iceland between 1979-1996 is due to the geothermal effect that you mention. H. Bjornsson, T. Jonsson, and T. Johannesson from the Icelandic Meteorological Office in their comment linked under “butchered” just above, showed that the map of volcanic activity (where geothermal effects should dominate) is incompatible with the expectation from geothermal contributions to surface temperatures, that there is no evidence for an enhancement of the geothermal flux during the period of interest, and that the geothermal flux is anyway approaching 3 orders of magnitude too low.

    D/K are obviously having great fun with their very late second careers as climate contrarians; but your reliance on them for info on climate-related matters is misplaced…

    [P.S. Ben Santer has just been elected to the National Academy of Sciences for his outstanding work on climate science - good work, yes?!]
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  9. Ken @104,

    This is what you originally said:

    "There are a few great minds who don't subscribe to the AGW theory"

    When challenged that has now changed to this:

    "He definitely does not subscribe to AGW - 'alarmist global warming"

    You are going to have to do better than that re Dyson, you cannot even concede that you misrepresented Dyson, so you move the goal posts as noted by JMurphy @105. That is, IMO, dishonest and disingenuous.

    Now onto the subject of this post. You are also going to have to do much better than this when asked about Lindzen's inane comments on natural variability:
    "Lindzen maybe, maybe not - right. It depends on how widely the limits of natural variability are drawn."

    Come on. So we simply adjust the time frame to fit Lindzen's ideology? That is poor Ken. And since when does Lindzen get to choose how widely the limits of natural variability are drawn and over which time? Given that you and BP are so well informed, and seem to understand what Lindzen is implying, please specify for us what these limits are. Also, please clearly describe for all of us how your missives here and the data support Lindzen's ideology?

    As for what is going on between 700 m and 2000 m. Really, you have to ask that? Trenberth (2010) has looked at this-- for the much debated 2003-2010 period, the positive slope of the OHC trace increases when one includes data below 700 m-- did you miss the first figure in Dana's post? Trenberth says:

    "However, independent analysis8 of the full-depth Argo floats for 2003 to 2008 suggests that the 6-year heat-content increase is 0.77 ± 0.11 W m−2 for the global ocean or 0.54 W m−2 for the entire Earth, indicating that substantial warming may be taking place below the upper 700 m."

    Also from the Figure's caption:
    "The differences between the black and blue plots after 2003 suggest that there has been significant warming below 700 m, and that rates of warming have slowed in recent years"
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  10. 108 - Chris.

    The lecture by Sanater is excellent in that it's always good to see some good science being discussed (I'd say the same for your posts); but also upsetting when you see the appalling work of the "skeptics" laid bare. It should really give "sceptics" pause for a little soul searching.
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  11. BP #107

    A useful contribution BP.

    I was listening to a radio interview with Josh Willis, and he made the point that most of the heat transfer action was in the top 10-20% of the oceans.

    With an average depth of 3700m - that puts it in the 0-700m layers.

    Maybe Albatross and Chris could also benefit from your contribution.
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  12. Albatross #109

    You are trying hard for a small win Albatross - how about -

    "Dyson does not subscribe to alarmist AGW."

    "That is, IMO, dishonest and disingenuous."

    BTW, allegations of dishonesty are banned under the comments policy. Are you immune from moderation Albatross?

    Trenberth 2010:

    "However, independent analysis8 of the full-depth Argo floats for 2003 to 2008 suggests that the 6-year heat-content increase is 0.77 ± 0.11 W m−2 for the global ocean or 0.54 W m−2 for the entire Earth, indicating that substantial warming may be taking place below the upper 700 m."

    I think you will find that Dr Trenberth is quoting the von Schukmann analysis from September 2009, which is the only 0-2000m Argo analysis published as far as I know.

    BP raised serious questions about the bumps in the VS global chart and the impossible rates of heat transfer involved.

    I asked Dr Trenberth about some aspects of the VS paper on 10FEB2010, and at that date he had not read it.

    Later he started quoting it in correspondence with Dr Pielke, published on his blog.
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  13. chris #108

    Trying to batter me with Douglass/Knox and their alleged faults elsewhere is a distraction from the numbers which you will not debate.

    "D/K are obviously having great fun with their very late second careers as climate contrarians; but your reliance on them for info on climate-related matters is misplaced…"

    I mentioned their paper and its quotation of Argo analyses from data by Willis and others. There are 5 or 6 other analyses which show no or little heat gain in the 0-700m layers.

    We have as far as I know only one Argo analysis 0-2000m from VS.

    BP #107 has suggested "Thermohaline downwelling itself does not transfer any heat into the abyss, it removes heat from there."

    So you tell me how the heat is getting from the surface down to 2000m and below that.
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  14. Ken @112,

    Stop misrepresenting me re Dyson....the way you quoted those phrases (first one yours, second one mine) makes it look like am am of the opinion that Dyson is "dishonest and disingenuous", which is not true. I was, of course, referring to a "skeptic" who was misrepresenting his stance on the theory of AGW, you. And you doing that latest trick just supports my claim.

    The fact remains the slope of the line increases (compare to that for 0-700 m) when one includes OHC down to 2000 m. You asked, you got an answer, yet you will not accept it. That is not 'skepticism', that is ideology Ken. And Josh said "most", not "all"-- Trenberth's figure is consistent with that. Now please go and argue strawmen somewhere else.

    And again, please provide some context--what the does this all have to do with Lindzen's illusion about the warming arising from internal variability?

    Re your question to Chris: "So you tell me how the heat is getting from the surface down to 2000m and below that."

    I am emailing a colleague (an oceanographer) to ask him about that today.
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  15. Ken Lambert at 23:50 PM on 18 May, 2011

    That's silly Ken. There is one bit of evidence that shows that there may have been rather little heat gain in a very short period of 0-700m Argo data. The fact that that's been pointed out in non-science journals and house magazines (and crappy journals) doesn't constitute "5 or 6 other analyses". It's a single analysis covering a very short period that might or might not be completely correct.

    It is worth highlighting the Douglass/Knox farragos. After all they seem to be the source for you information on this subject. There's a huge wealth of science that bears on this subject (e.g. see below) and yet you bring a truly dismal flawed analysis in support of your viewpoint. If you're not going to be skeptical, then we may as well point out the flaws in your sources.

    "So you tell me how the heat is getting from the surface down to 2000m and below that"

    Why not find out yourself? We know that the deep oceans are absorbing heat. There is simply too much evidence to discount that empirical observation (see also Purkey and Johnson (2010) and Song and Colberg (2011), who indicate that a substantial proportion of recent sea level rise may be due to deep ocean heating).

    I'm not an oceanographer, and so I don't have priviliged insight into the mechanisms of deep ocean heat transfer. In the meantime you could try, for example, Masuda et al (2010) who have identified pathways for deep ocean heat transfer in the North Pacific using simulations, or Kao et al (2010), who have shown that major tropical ocean storms, especially tropical cyclones can transfer surface warmth to the deep oceans. There's a large scientific literature on this. If you're interested you only have to look.

    Your style of "debate" is boring, since you plump for truly dismal analyses, and argue from there. What's the point? We know that the Earth is warming under the effect of a radiative imbalance (2005 and 2010 had record warmth in the GISS analysis during a period of an extended solar minimum, the largest cosmic ray flux directly recorded etc.), analysis of sea level rise indicates that the oceans continue to absorb heat, evidence supports significant deep sea thermal heat absorption...

    ..but there are uncertainties. The scientists that are expert in these arenas haven't fully accounted either for the recent short term sea level budget nor the budget in the radiative imbalance. It's very difficult to do so over very short periods of time. So what's the point of "debating"? What are you expecting to discover by "debate" that the scientists haven't already?
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  16. "So you tell me how the heat is getting from the surface down to 2000m and below that."

    I'm certainly not an expert in this field, but this recent paper (Eddies Found to Be Deep, Powerful Modes of Ocean Transport Connecting Atmospheric Events and Deep Ocean) looked interesting as a possible method for transporting heat from the surface. That's not what they were looking at, so more study would be needed, but it shows that there is interaction between the ocean surface and the ocean floor.
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  17. #111 Ken Lambert at 23:20 PM on 18 May, 2011
    I was listening to a radio interview with Josh Willis, and he made the point that most of the heat transfer action was in the top 10-20% of the oceans.

    With an average depth of 3700m - that puts it in the 0-700m layers.


    Prof. Rahmstorf's introduction to the thermohaline circulation and deep mixing is a profound one.

    Encyclopedia of Quaternary Sciences
    Edited by S. A. Elias. Elsevier, Amsterdam 2006.
    Thermohaline Ocean Circulation.
    by Stefan Rahmstorf

    Downwelling basically occurs in two regions of the world oceans, at the North Atlantic - Arctic Ocean boundary and at the Antarctic coast. It could also occur in the North Pacific, if salinity would be higher there, but currently it is in a switched-off state in that region.

    The total amount of heat transported to polar regions by surface currents feeding bottom water formation is ~1-1.5 PW globally, which corresponds to a global average flux of 2-3 W/m2. However, this heat is not pulled down to the abyss, quite the contrary. Seawater, before going down, should get rid of it, otherwise it could not attain a sufficiently high density. Therefore this heat is deposited into polar air, in part by increasing its temperature, in part as latent heat of evaporation. Subsequently this heat is radiated out to space, as polar air is still damn cold, there is no other region colder than that where the excess heat could go (net heat transfer always happens from warmer to colder heat reservoirs, second law).

    Downwelling always happens to seawater whose temperature is close to freezing, its salinity is increased either by evaporation or brine exclusion (when part of the water freezes over - ice does not like salt). Now, that temperature is not determined by environmental factors, but the physical properties of seawater, therefore it is quite independent of climatic variations, at least as long as there is an ice margin.

    What can change is the location of downwelling. Not much in the Southern Ocean, where it is determined by the Antarctic coastline. However, in the North Atlantic there is a ridge running across the basin between Europe and Greenland that separates the Arctic basin from the rest. Currently the ice margin lies north of this line, so downwelling goes to the Arctic basin and subsequently to the Atlantic via overflows along the ridge. In glacial times, this entire area was covered by ice and downwelling happened south of the ridge, going directly to the deep Atlantic. That's a difference.

    However, under current conditions, whenever ice margin moves a bit, downwelling just follows it smoothly. To break the process, polar ice should be removed year round altogether, but that will not happen any time soon (not in the next few thousand years for sure).

    The talk about shutting down the THC by introducing a vast amount of fresh water into the Arctic basin is just that, talk. Unlike at he end of the last glacial, there is no fresh water body around comparable to Lake Agassiz.



    Anyway, this shutdown can only be temporary (spanning several centuries), as the MOC (Meridional Overturning Circulation, which THC is part of) is not driven by temperature and/or salinity differences, but by heat diffusion into the abyss elsewhere by turbulent mixing.

    As THC itself removes heat from the oceans (at a global rate of several W/m2), if one is interested in heat deposition at depth, should look elsewhere.
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  18. Chris #115

    "That's silly Ken. There is one bit of evidence that shows that there may have been rather little heat gain in a very short period of 0-700m Argo data. The fact that that's been pointed out in non-science journals and house magazines (and crappy journals) doesn't constitute "5 or 6 other analyses". It's a single analysis covering a very short period that might or might not be completely correct"

    No its not silly Chris. Your derogation does not have any effect on me.

    Who are the 6 'Teams' contributing a curve each to the 0-700m Charts quoted here in Fig 1 and Fig 2:

    http://www.skepticalscience.com/news.php?p=2&t=78&&n=202

    All show the 2001-03 step jump and subsequent flattening of OHC.

    Purkey & Johnson show only 0.1W/sq.m from the deep oceans.

    So your case relies on nearly all the heat being in the 700-2000m depth range, of which there is only the one bumpy spliced VS Argo analysis.

    BP #117 has an interesting point. The heat travelling to the poles in the surface currents is given up to the polar air, before densifying enough to go down.

    That is where I suspect you will find Dr Trenberth's missing heat - off to space over the polar regions.
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  19. Ken @118,

    This has been getting silly for some time Ken, mostly because of your recalcitrance and the shifting of goal posts. Additionally, you continue to misrepresent people (Chris in this case) when you say things like:

    "So your case relies on nearly all the heat being in the 700-2000m depth range"

    Re BP @117, you say:

    "BP #117 has an interesting point. The heat travelling to the poles in the surface currents is given up to the polar air, before densifying enough to go down."

    It may be an interesting point to you, but it is not novel, nor is it entirely correct. There are other processes at work too at high latitudes, including evaporation and brine exclusion, it is not called the thermo circulation, but the thermohaline circulation, although MOC is probably the best descriptor. It is odd that you and BP are arguing that the OHC can't be increasing below 700 m, but do not fully understand that there are mechanisms by which deep ocean heat uptake can occur.

    If you feel that you know better, please write a paper instead of playing the omniscient peanut gallery. But you might wish to read the references provided to you @115. You might also wish to take not of the following from Trenberth and Caron (2001):
    "Atmospheric transports adjusted for spurious subterranean transports over land areas are inferred and show that poleward ocean heat transports are dominant only between 0° and 17°N. At 35° latitude, at which the peak total poleward transport in each hemisphere occurs, the atmospheric transport accounts for 78% of the total in the Northern Hemisphere and 92% in the Southern Hemisphere. In general, a much greater portion of the required poleward transport is contributed by the atmosphere than the ocean, as compared with previous estimates."

    You ignored the information provided to you @115 by Chris and @116 concerning how heat uptake can occur in the deep ocean. And I'll add another, by Garrett and St. Laurent (2002). Do you deny that there are mechanisms in place that lead to deep ocean mixing and heat uptake there? And as shown above BP is arguing a strawman regarding the polar regions, also one reference that Chris provided talks about deep mixing on account of tropical storms.

    I am not going to engage you anymore if you continue with this charade. And I'll remind you yet again that you still continue to ignore this question:

    "And again, please provide some context--what the does this all have to do with Lindzen's illusion about the warming arising from internal variability? "
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  20. Just quickly perused a paper by on of Dr. Scott Mandia's students and it includes this great quote by John Adams that I think applies to 'skeptics' and those in denial about AGW on this thread (and in fact all threads):

    "Facts are stubborn things; and whatever may be our wishes, our inclinations, or the dictates of our passion, they cannot alter the state of facts and evidence."

    Dr. Richard Lindzen, I am also looking at you.
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  21. #119 Albatross at 01:18 AM on 20 May, 2011
    It is odd that you and BP are arguing that the OHC can't be increasing below 700 m, but do not fully understand that there are mechanisms by which deep ocean heat uptake can occur.

    Quite the contrary. If you compare data provided by Fig. 5 (middle panel) Schuckmann 2011 (OHC above 1500 m) and NOAA NODC OCL Global Ocean Heat Content (OHC above 700 m), based on Levitus 2009, it turns out much more heat is sequestered between 700 m and 1500 m than in the upper 700 m (expressed as the partial planetary imbalance at TOA going to the respective layer).

    2005-2010, 0-700 m: 139 ± 55 mW/m2, 700-1500 m: 396 ± 57 mW/m2

    That is, in this period about three times more heat went to the 800 m thick layer below 700 m than above it. It is even more interesting for the last five years.

    2006-2010, 0-700 m:  −7 ± 67 mW/m2, 700-1500 m: 427 ± 56 mW/m2

    That is, since the beginning of 2006 nothing stayed above 700 m. Both studies provide proper error bars, so these results are unequivocal.

    On the other hand the studies do not provide any description of a conceivable physical process that could accomplish such a quest. Nor could I find other studies attempting the same. Therefore if one does not "fully understand that there are mechanisms by which deep ocean heat uptake can occur" without ever touching the upper layers, one is not alone.

    Albatross, if you happen to know such a reference, please show us. Otherwise we are forced to believe either Levitus 2009 or Schuckmann 2011 is flawed. Or both.
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  22. BP @121,

    I'm running around putting out some "fires" right now and tonight-- so I do not have time to fact check your numbers or reasoning. But a quick read of your post suggests that you are possibly contradicting earlier assertions made by Ken and perhaps even yourself. I would caution arbitrarily comparing numbers for different depths from different studies as they process the data differently and make different corrections. I can't recall, does VS 2011 separate out the OHC into layers, say 0-700, 700-1500 etc.? If yes, then you should be comparing those numbers.

    Anyhow, IIRC, you both seem to think that the heat cannot be going below 700m, and if it is, only a trivial amount is. Now above you seem to be arguing that too much heat is being mixed downwards, although I'm pretty sure that that deduction is probably b/c of the above-mentioned issues.

    My point was and still is this-- if one includes the data below 700 m from 2003 onwards (as per Trenberth 2010), the positive slope of the OLS line fitted to the OHC increases. Do you deny that?
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  23. BP #121

    "On the other hand the studies do not provide any description of a conceivable physical process that could accomplish such a quest. Nor could I find other studies attempting the same. Therefore if one does not "fully understand that there are mechanisms by which deep ocean heat uptake can occur" without ever touching the upper layers, one is not alone"

    Precisely.

    If heat is being found by VS and Levitus in the 700m to 2000m range and NOT in the 0-700m layers, then a physica;l explanation is necessary.

    Are we being asked to believe that warmed surface water travels down through a 700m column of water of lower temperature without giving up heat to that column?

    For that to occur the warm surface water must be packaged in insulated bags which suddenly pop open when propelled below 700m.

    Albatross #122

    "Anyhow, IIRC, you both seem to think that the heat cannot be going below 700m, and if it is, only a trivial amount is. Now above you seem to be arguing that too much heat is being mixed downwards, although I'm pretty sure that that deduction is probably b/c of the above-mentioned issues"

    No, what BP is saying is that heat cannot travel below 700m without showing up in the 0-700m layers. That means that one could have heat in both places, but heat travelling from the top down must produce a warm gradient through the column however far down it goes.
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  24. "Are we being asked to believe that warmed surface water travels down through a 700m column of water of lower temperature without giving up heat to that column?"

    All that is required is for heat in the 0-700m layer to be transported to deeper water at a rate that balances the influx into the 0-700m layer from above.

    Remember, surface waters are sandwiched between the atmsophere and deeper waters. The heat balance of surface waters is governed by inputs/outputs from above and inputs/outputs with deeper waters. A lot of heat can move through surface waters without there being a net gain in heat in surface waters.
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  25. I want to add that, from an oceanography viewpoint, the real value of the Argo floats isn't in balancing the global heat balance, important though that is. The oceanographic interest is in understanding the interaction between water masses at depth, and the implications for fluxes of matter, energy and, ultimately, biological processes. Of course, the findings will impact climate science.

    We know very little about deep sea processes, and I'm sure there will be surprises ahead. Exciting times for physical oceanographers!
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  26. Stephen @124,

    Thanks. BP is also very likely not comparing apples with apples-- he is conflating different data. And notice how the goal posts have shifted...the 'skeptics' are shown that heat uptake is occurring in the deep ocean waters and that doing so increasing the positive slope in OHC, the 'skeptics' do not acknowledge that but instead then ask how heat uptake can occur down to 2000 m or deeper. That is addressed, the 'skeptics' ignore that, and then try to demonstrate that that is not what is happening and that it is 'unphysical' using data from different datasets (yes Argo, but with different assumptions, post processing, corrections etc.) .

    And note how they repeatedly refuse to answer this question:

    "And again, please provide some context--what the does this all have to do with Lindzen's illusion about the warming arising from internal variability?"

    It has been presented bold text, underlined text, so I know they have seen it.
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  27. There may be many processes and oceanographic phenomena we don't yet understand.

    http://www.sciencedaily.com/releases/2011/05/110518130921.htm I noticed this point as relevant to some of the discussion.
    "... scientists were able to document similar fluctuations of the "Deep Jets," deep currents down to 3000 m with speeds of 10-20 cm/sec. They flow along the equator, crossing the entire Atlantic, with flow reversals every few hundred meters. "These jets are generated in the deep ocean, and their energy apparently propagates upwards through the water column.
    Once near the surface, this energy affects currents and temperatures ..."

    I have no idea how many other such tremendous forces may be moving gigantic volumes of water around in this and other regions, but I'm certain there are some.
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    Response:

    [DB] Hot-linked URL.

  28. Sorry, missed the link.
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  29. Stephen Baines #124, #125

    For those in/out heat fluxes to be balanced, an equilibrium temperature or temperature profile of sorts must have been established in the 0-700m layers.

    The surface exchange includes direct radiation, evaporation, rainfall, ice freeze and melt etc. The exchange between the 0-700 and 700+ depths would include conduction and what else? Is there any study which describes these heat flux transport rates and shows comparable fluxes at the top and bottom?
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  30. #123 Ken Lambert at 23:30 PM on 20 May, 2011
    Are we being asked to believe that warmed surface water travels down through a 700m column of water of lower temperature without giving up heat to that column?

    For that to occur the warm surface water must be packaged in insulated bags which suddenly pop open when propelled below 700m.


    Something like that may indeed be going on, although the science is most probably very far from being settled. Anyway, several things seem to emerge. The deep mixing rate in the open ocean is at least an order of magnitude smaller than that necessary to support the meridional overturning circulation. Which is not a heat engine, it does not produce, but consumes mechanical energy. This mechanical energy (in the terawatt range) is supplied by deep tides and wind-generated internal waves, and is dissipated intermittently over small regions of complex bottom or boundary features causing vigorous vertical turbulent mixing there.

    If deep mixing of heat occurs in this manner, it can circumvent the upper 700 m over most of the oceans (without resorting to insulating bags to carry heat down).

    Most of the deep turbulent mixing (about 80%) happens over the southern ocean, the region which was poorly measured until quite recently.

    In any case, surface warming itself would not cause deep mixing, it would diminish it instead by making stratification more stable. There are other ill-understood forces at work here, with quite large time constants that control general circulation patterns which move vast amounts of heat around (this looks like the primary source of so called internal variability).

    There is a good review article online that summarizes it all.

    Annual Review of Fluid Mechanics
    Vol. 36: 281-314 (Volume publication date January 2004)
    DOI: 10.1146/annurev.fluid.36.050802.122121
    Vertical Mixing, Energy, and the General Circulation of the Oceans
    Carl Wunsch and Raffaele Ferrari

    "MODELS
    Numerical general circulation models are a powerful tool for understanding the ocean. However, in their present state they prove not as helpful in elucidating mixing and energetics as one might anticipate. Several sources of difficulty can be identified, including the arbitrary introduction of eddy-mixing coefficients with numerical values tuned to provide realistic simulations. These lack any link to the underlying sources of the implicit turbulence. That is, they imply a turbulent field, but one without an associated energy source; this omission is of particular concern in models without any wind forcing, including even simple box models [e.g., variants of Stommel (1961)]. Another source of difficulty is the near-ubiquity of the Boussinesq approximation (several versions in several numerical representations), which renders problematic even a gross energy budget for the system".


    Even if they say "Reasons of space preclude a serious discussion of the energetics and mixing in models", it is clear that GCMs (computational General Circulation Models) are lacking in a most embarrassing way. They are not able to resolve the small scale processes that keep the MOC (Meridional Overturning Circulation) alive while the underlying energetics is not modeled at all. That much about models working from first principles.

    Anyway, I would like to see trends in wind fields over the southern ocean and an analysis of the recent Supermoon's effect on internal tides.
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  31. BP #130

    I have often thought that the geothermal heating from the ocean floor (reputedly 0.1W/sq.m) globally must have a confusing effect on OHC measurement.

    Squirting heat from vents driectly into bottom water and conduction from a warm immersed bottom would be much more efficent heat transfer mechanisms than radiant heating of the surface.

    With a 0.1W/sq.m flux constantly rising from the bottom through the column toward the surface - some effect on mixing and other transport mechanisms would be expected.
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  32. #131 Ken Lambert at 23:41 PM on 24 May, 2011
    Squirting heat from vents driectly into bottom water and conduction from a warm immersed bottom would be much more efficent heat transfer mechanisms than radiant heating of the surface.

    Yes, its role is discribed by the following paper in some detail.

    Journal of Geophysical Research - Oceans, 2001, 106, (C12), 31141-31154.
    doi:10.1029/2000JC000532
    Geothermal Heating and its Influence on the Meridional Overturning Circulation
    Jeffery R. Scott, Jochem Marotzke & Alistair Adcroft

    Anyway, the upshot is that in order to keep MOC moving, heat has to get into the abyss by whatever means, including geothermal flux at the bottom and deep turbulent mixing at boundaries driven either by wind stress or tidal forces.

    However, the net heat storage resulting from this flow is very small, because there is a feedback loop that readily removes (or resupplies) most of this heat again by feeding in just the necessary amount of very cold polar water.

    Journal of Climate, 2011
    ISSN 0894-8755.
    On the linkage between Antarctic surface-water stratification and global deepwater temperature
    Ralph F. Keeling & Martin Visbeck

    This loop is not controlled by average surface temperature, but by the coldest surface water temperatures available, which in turn are fully determined by physical properties of water/ice (at least as long as there is sea ice anywhere on the globe).

    The bulk of oceans is a polar thing, even in the tropics, warmth is only a thin top layer. Average temperature of seawater is close to 3°C while about 57% of it is below 2°C. This is how we know we are still in an ice age. In the good old days when there was no sea ice, deep water temperatures exceeded 20°C (as it is the case with present day Red Sea).
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