Bishop Hill The missing tropical hotspot
Aug 19, 2013 Climate: Models Climate Dialogue has another of its learned coffee mornings up and running, this time examining the missing tropical hotspot in the troposphere. In it we learn from Carl Mears that
...the tropospheric hotspot is often presented as some sort of lynchpin of global warming theory. It is not. It is just a feature of a close-to-unstable moist atmosphere.
Now this is pretty surprising to me. If I recall correctly, the tropospheric hotspot was behind the big story of the IPCC's Second Assessment Report, the "discernable influence" of mankind on the climate; his fingerprints left all over the scene of the crime.
This is all rather reminscent of the Hockey Stick, which everyone now agrees is peripheral to the global warming hypothesis, but was nevertheless promoted by the IPCC as if it meant something.
Reader Comments (67)
Another shifting of the goalposts by the Alarmists.
They are taking their lead from "1984"
“He who controls the past controls the future. He who controls the present controls the past.” ― George Orwell.
When you look at now GISSTEMP and CRUTEM have been manipulated the parallels are frightening.
But these creeps can't control the future and that is substantial global cooling.
Obviously the hotspot is in the deep oceans, in fact as Al Gore said
So the heat has gone from the troposphere down past the deep oceans into the Earth's core, right now Gore is in a lab somewhere building a rocket ship to launch mankind’s last son away from this doomed planet to another where he will be like a god to the poor backwards people of that planet, his only weakness CO2 polluted chunks of his home world. He’ll be known as man of Goretex Man of Wind!
/sarc
Of course the missing hotspot is not important.
Nor is the flat-lining global temperature over the past 17 years, nor any study that might suggest that climate sensitivity is lower than assumed by the AGW alarmists, nor anything else that points to an over hyped global temperature scenario.
What is important then? Only what we're told by the alarmists - pathetic!
Andrew, you're right I'm sure to go back and mock the way the hotspot once played its part in IPCC mythology. But, as I understand it, Richard Lindzen would agree with Carl Mears on the hotspot as a predicted consequence of atmospheric physics, regardless of whether man is causing any warming. Lindzen is confident enough in the theory to say that this shows that there's something wrong with our current measurements, either surface or further up. We should note in passing how the premier sceptic is willing to discount data when it doesn't suit him :) But, not being an expert, I'd trust Lindzen's judgment on this. Another indication of how primitive climate science is, as he would be the first to admit. As Jonathan Jones summed it up in the pub in Oxford this time last year: hard problem, bad data. One of the reasons his physics colleagues think he's mad getting involved publicly. And probably not the only one. :)
Lucia has a good recap of the issue at
http://rankexploits.com/musings/2008/who-expects-a-tropical-tropospheric-hot-spot-from-any-and-all-sources-of-warming/
How long before the "polar amplification" is lost in the climate mists of time. That great CAGW signature which is not behaving itself!
How long before the Arctic summer melt is not that important?
After all snow is a thing of the past!
Was not the whole Reason for a 'moist, unstable atmosphere,' the supposed FACT that the tropospheric hot spot would trap and hold water vapour in the lower atmosphere, rather than releasing heat to the stratosphere (and thereby, into space)?
It seems to me in light of that, that a missing hot spot is of paramount importance.
So, beyond the basic absorption/reradiation response of CO2 and other molecules to some wavelengths, which I don't dispute, there is no evidence experimental or observational, which links GHG with actual heat 'trapping' or heating of the atmosphere? The kind of evidence I asked about in a discussion post many months ago, when not even a proposal of how to find such evidence was put forward. What is the best evidence? Where is the logical sequence of experiments and observation linking the GHG with any warming?
Rhoda: for some reason the phrase "invincible ignorance" comes to mind.
I thought an inordinate amount of effort had been spent in trying to show that the hotspot was there. The thermometers couldn't detect the temperature so it was much more reliable to detect it by measuring wind speed. Is this saying that was all a waste of effort anyway?
Rhoda
you are being unkind the warmers have plenty of evidence of CAGW
- Consensus 97% of scientists believe - wow must be true
- the hockey stick - how can someone like Michael Piltdown Mann (Nobel Laureate almost) be wrong
- deep ocean missing heat - how can Keith Trenberth (Nobel Laureate almost)
They also have Gerald North rooting for them. Give them a break as they are saving the planet!
The whole AGW movement is uninterested in evidence-based science, as someone much more poetic than I pointed out a few years back.
Dear Kev just told Romm that the hotspot keeps moving about...I am sure it will get back to the stratosphere one day, after visiting Russia, China, the USA or wherever else it happens for the weather to be hot...
I got as far as Figure 3 and read: "The two distributions overlap, indicating consistency of this set of observations with the models, though the mean value shown by the observations is clearly lower than that predicted by the models." At that point I concluded the piece was some kind of sophisticated joke.
So the missing hotspot never was important, just like surface temperature never was important either, once it stopped going up.
If it wasn't all so tragic, it would be funny.
I suspected CAGW was a new religion but now it looks more like a doomsday cult.
This was Richard Lindzen on WUWT on 17th January 2011:
The piece was called A Case Against Precipitous Climate Action and was originally published by the GWPF. And, while I remember, over the weekend BH nym eSmiff has been trying to persuade us that the GWPF is a false flag operation to discredit scepticism. Well, either they are or he is, I guess one can say for certain.
Is it not the case that the fact that there has been no tropical hotspot in the troposhere, is simply a reflection that there has in fact been no warming these past 17 or so years, and indeed, with the exception of the step change in and around the Super El Nino of 1998, according to the satellite data no other warming these past 33 years. If there has been no warming why would one expect to see a change in the tropical hotspot in the troposphere?
Against this background, I am not sure why Lindzen, or others, would question the data and suggest that there must be something wrong with this particular measurement (see Richard Drake Aug 19, 2013 at 9:49 AM). It always concerns me when people question empirical unadjusted observational data, before first questioning the theory. If theory and data do not match, the first step is to question the theory. That is not to say that the data must always be considered gospel, but if the only stand alone issue with the data is that it does not accord with some new fangled theory then this issue is not in itself much of a reason to question the data. It is more of a reason to question the theory.
Further, whilst I have not looked into this, is this not in some way coupled to Miskolczi findings, based upon empirical observational data regarding the atmospheric absorption of IR obtained from radiosonde data(weather balloons), in which he found that there has been no net change in IR absorption, and the global average IR optical thickness of our real world atmosphere these past 60 or so years has remained unchanged at ~ 1.87 notwithstanding an increase of more than 20% in the levels of CO2 in the atmosphere?
As I understand matters, his findings (as opposed to theorising as to what his findings mean) are not substantially challenged, although of course data issues and the robustness of the data are raised. That said, every data set in climate science has its issues, and very few are what a reasonable person would consider robust. Often one is left to work with what is the best of a bad bunch.
That of course, leads to caveats (or should do so if scientists were open and honest about their data and its limitations), but assuming that Miskolczi observational findings are correct (within the limits of the robustness of the underlying data from which this empirical finding was taken), it may suggest that one would not expect to see any tropical hotspot in the troposhpere because IR absorption in the real world conditions of the atmosphere itself is not taking place as those who espouse the AGW theory would have one consider it should take place.
Bish
You don't have to recall, you can actually go back and check :-) The SAR is here.
It is mentioned as one piece of evidence in Chapter 8, but it doesn't seem to be a particularly big story in the Summary for Policymakers or Technical Summary. The discussion in the chapter does highlight the uncertainties.
(However, I agree that this was not the case for the Hockey Stick in the TAR, which was indeed given huge prominance in the SPM, even though it was only based on a single study).
I do not think whether the mid troposphere hotspotwas made into something in previous IPCC reports is material here. As John Christy stated
"A particularly obvious feature of this expected warming, and is a key focus of this blog post, is that this warming increases with altitude where the rate of warming at 10 km altitude is over twice that of the rate at the surface. This clear model response should be detectible by now (i.e. 2012) which gives us an opportunity to check whether the real world is responding as the models’ simulate for a large-scale, easy-to-compare quantity. This is why we care about the tropical atmospheric temperature."
It is a big thing because it is one of the many improtant failings of climate modelling.
Aug 19, 2013 at 10:49 AM | Richard Drake
///////////////////////////
I don't doubt that there was some 20th century warming, but I am sceptical as to how much warming there has been since the late 70s.
I would suggest that the evidence is at its most robust for the warming up to the 1940s and the evidence for late 20th century warming is conflicting (heck even the tree data suggests that it was not happening and that is why it was cut and the 'adjusted' instrument record spliced on - the divergence problem).
In theory, the satelitte data ought to be the most reliable source of temp data (it does not suffer from UHI, poor station siting, lack of screen maintenance, endless adjustments the appropriateness for which is moot etc. although it does have some issues of its own with equipment calibration and degradation, orbital drift etc) and this does not suggest that there was very much warming; indeed only the temp step change in and around the Super El Nino of 1998.
I consider that the most probable explanation is that we do not know and understand how the climate and atmosphere works, not that the troposhere data is wrong. May be we need to consider different ways as to how the atmosphere/climate responds and how this leads to atmospheric temperature changes, before suggesting that the data itself is wrong.
PS. I consider that the observation by Richard Betts is correct, but as ConfusedPhoton p;oints out, the relevance is not whether the lack of a tropical hotspot in the troposhere in some disproves AGW, but rather it demonstrates that we do not understand enough about Earth's atmosphere and how it works in practice to model it with any expectation of being right. Until we begin to properly understand the complex workings, we cannot begin to expect to get the models right (or as nearly right as chaos will permit).
If the models show it and it isn't there, should we not throw out those models as non-physical?
If there is no proposal for an experiment to show GHG-induced warming, no model prediction coming true and no observation that unequivocally shows that GHG warming is taking place, what's left? That is, if all the things which now don't matter are excluded, what really does matter?
And no, likelihood statements are not harmless fun if correctly qualified, in the hands of a context-illiterate journalist or PR man they are potent weapons of propaganda.
At what point (height) is the postulate of adiabatic expansion considered to be wrong? (logically it must become false at some point in the atmosphere, otherwise no heat could be radiated to space).
Well in response to the hotspot versus models papers Scmidt of RC replied that the tropi tropo hotspot should arise even with the solar warming theory and that it was really stratospheric cooling that was the fingerprint of AGW (IPCC of course had said that it was the combination). Anyway there has been no stratospheric cooling either since 1995. A fact that was and still is conveniently overlooked by everyone. Of course all you have to do is chose the right smoothing end point and this fact disappears along with the lack of global warming and the lack of ocean warming. You can then entirely rely upon extrapolations from the wild-ass guesstimates that were made prior to the substantially more accurate satellite era. So great to be in the soft sciences; anything goes!
At the very least though the hotspot tells us that there is no significant water vapour feedback because "if it should be anywhere then it should be in the tropics" to quote Dessler.
The easy way to win an argument is to use the "experts" own words against them. They are relying on journalists having the memory capacity of a piece of cheese but all their original words are right there on the internet.
I struggled through to the end of the "article" by Carl Mears and wonder why we are giving him a bad press?
Basically his conclusions were that something said in an IPCC report was complete bollocks, that finding a hotspot in the Tropical Troposphere would not be proof of AGW and that anway we do not yet have enough data to say whether there is or is not a hotspot.
What's not to like?
Aug 19, 2013 at 12:56 PM | Dung
It ignores the fact that the "moist atmosphere" is the positive feedback that was predicted to make AGW a problem.
Simple physics says that greenhouse gases need that positive feedback to be a significant problem.
No Tropical Hotspot means that the positive feedback isn't big enough to be noticed... therefore it isn't big enough to be a significant problem.
That is why it is important. The missing Tropical Hotspot doesn't disprove AGW but it does disprove cAGW.
And any downplaying of the missing Tropical Hotspot allows people to still play the Precautionary Principle card.
Aug 19, 2013 at 12:56 PM | Dung
It ignores the fact that the "moist atmosphere" is the positive feedback that was predicted to make AGW a problem.
Simple physics says that greenhouse gases need that positive feedback to be a significant problem.
No Tropical Hotspot means that the positive feedback isn't big enough to be noticed... therefore it isn't big enough to be a significant problem.
That is why it is important. The missing Tropical Hotspot doesn't disprove AGW but it does disprove cAGW.
And any downplaying of the missing Tropical Hotspot allows people to still play the Precautionary Principle card.
M Courtney
I may have been somewhat brief but I did cover that issue as follows:
Well, soon all that will be left is the “radiative forcing” claimed for CO2.
Leaving aside the question of what the assumed T-vs-CO2 correlation is based on, I should like to know how it is actually used in the climate calculations. Are there any references in the open online literature?
If the supposed warming is applied locally to every element of the atmosphere (that is, similar to the heat addition resulting when chemical reactions are present) and the response is followed dynamically, then it would have to be admitted that they are at least trying to do the right thing and the only argument would be about the form of the correlation and its magnification through a conjectured extra water vapour feedback. The latter should also surely fall out automatically from the calculations if done properly and should not need to be found from any fiddle factors approximating π.
If on the other hand the warming is applied simply by scaling up the radiation that is effectively received from the Sun then it seems that they could not fail to find a temperature increase in the atmosphere: the increase would be an inevitable hard-wired component. If this is what they do I believe it to be completely wrong.
Mark Well
It's not merely a correlation, the effects of CO2 (and other GHGs, and clouds and aerosols) on shortwave and longwave radiation flows are modelling mechanistically.
One of the key papers on the radiation calculations in the Met Office model is here. I expect it's probably paywalled, but I'd be happy to send you a copy if you're interested. Met Office email addresses take the form name.surname@metoffice.gov.uk
Must read: John Christy's Aug. 11 2:25 posting at:
http://www.climatedialogue.org/the-missing-tropical-hot-spot/
Aug 19, 2013 at 11:23 AM and following | Unregistered Commenterrichard verney
++
Well said. Thank you.
Richard Drake makes a point that is not given enough exposure.
The enhanced global warming theory has nothing directly to do with carbon dioxide. Any warming or cooling for any reason is potentially amplified or attenuated by an increase or a decrease in water vapour which quite literally does the real heavy lifting in the global cooling mechanism provided by convection. Without this convection, driven mostly by water vapour, the average global surface temperature could reach 70°C.
Ignoring convection is like ignoring aerodynamics and arguing that heavier than air flying machines are impossible. One could think of the convection mechanism like shuttle buses hanging about until they get enough on board to fill up and go. When parcels of air get enough thermal energy they lift off like bubbles in a lava lamp and take the energy they have acquired by whatever means higher in the atmosphere where some of it radiates to space.
Here again the role of carbon dioxide is largely incidental. The atmosphere is well mixed at the scale that matters and the gases expand together to cause convection. All that increased carbon dioxide concentrations can do is to make a parcel of air set off with just a bit less water vapour in it than it would otherwise do. This means it is conceivable that the sensitivity of the climate to warming from carbon dioxide could be very low at those temperatures and locations where water vapour is abundant. At low temperatures and in locations where water vapour is less abundant those non-condensing greenhouse gases like carbon dioxide will have a greater role.
It follows from this that if the solar radiation reaching the Earth was temporarily reduced drastically for long enough for water vapour concentrations to become very low, then without plenty of non-condensing greenhouse gases like carbon dioxide we could be in real trouble in re-establishing our water vapour blanket. In Melvyn Bragg’s 14 February 2013 ‘In our Time’ programme it was stated as matter of fact that we now have too much carbon dioxide to enter into another ice age. That sounds good to me.
It's striking that Richard Betts doesn't tell us whether he thinks the hotspot is an anthropogenic signature - only that this wasn't greatly emphasised in the SAR. And, further, whether he thinks its apparent absence is down to bad data and if so, which data.
If the man from the Met won't nail his colours to the mast I don't really feel a great need to myself. I put up Richard Lindzen's view not because I think the guy's infallible but because it shows:
1. that one can be a (policy) sceptic without buying the 'hotspot is a key anthropogenic signature' trope
2. what a primitive state climate science is in, both in theory (modelling) and data.
In this I'm with Rhoda and Martin A, though I'm happier to use the language of sensitivity than them and that's precisely because of what I see as the primitive state of the field. But the man from the Met won't it seems tell us his own view. That for me speaks volumes. There is no basis here for policy costing thousands, let alone trillions.
Compare this reticence with David Coe's boldness and insight on the carbon cycle. And if David's right the truck's already been driven through the C in CAGW for good, pretty much. That guy really deserves a medal. I advise all BH regulars to re-read the ongoing debate in that thread - and Martin A to put up a Discussion with all the links, as he said.
Why a spot? Wouldn't it be more of a belt? Anyway it's not there, except on the models...
And speaking of hot planetary belts, How many here remember the Flame Belt around Venus in the wonderful first Dan Dare cartoon series of the Fifties? It didn't prevent the glorious blue skies and green luxuriant landscapes enjoyed by both Treens and Therons in both hemispheres as so beautifully drawn by Frank Hampson.
Ah, John, now you're talking real science. :)
The predicted Tropospheric hot spot has never been detected, here are your options:
There is no hot spot therefore AGW is not happening.
There is no hot spot but it does not matter because the IPCC prediction was garbage.
There is no hot spot but we do not yet have enough data to verify it.
There is a hot spot but we do not yet have enough data to verify it.
A hot spot is only caused by a surface temperature rise and regardless of why it rises.
Would people like to add more and say if any of them have any relevance ?
Aug 19, 2013 at 2:40 PM | Richard Betts
Thank you for your response. My questions are very elementary. You say that the effects of CO2 are modelled. I am not sure what ‘mechanistically’ means in this context.
I have no experience of radiation, but I believe that the effects of CO2 are computed using HITRAN or MODTRAN and to do so I think it is assumed that the atmosphere is static. Presumably such calculations have been verified against lab experiments.
As an aside, when the thermal conductivity of CO2 is measured (that is, the constant of proportionality between temperature gradient and heat transfer by diffusion), radiation must also be present in the experiment. Doesn’t this mean that ordinary conduction in CO2 already includes radiation, at least to some extent?
The assumption of a static atmosphere in the above calculations is not necessary objectionable because if the effect is applied locally it can probably be assumed to move with the fluid elements. Fluid velocities are small in comparison to the velocity of the photons. External radiation hits a control volume and changes its internal energy. The energy is later given up, for example, when the CO2 component of the fluid itself starts to radiate.
CO2 radiative forcing is usually expressed as something like 1.6 W/m2, which is a flux of thermal energy. The atmosphere is a fluid and by definition an unconstrained fluid cannot remain immobile when disturbed, as it most definitely would be by an abrupt addition of energy. Hence the assumption of a static atmosphere, as was probably OK for HITRAN/MODTRAN, will not do for the NS equations.
This is why I asked and why I should like to know how radiative forcing is used when solving the fluid mechanics equations.
I am grateful for your reply, Dr Betts. If you would be so good as to explain what is done in simple language it would perhaps be of interest to others here and it would not be necessary for me to delve into an unfamiliar subject.
Mark Well
I wish you the best of luck but please remember that Dr Betts is employed by the Met Office and therefore would suffer career problems if any answer he gave might not be on MO message.
Very sad but very true.
Steady on guys, don't over-egg the pudding. Richard Betts doesn't have to answer every question of every sceptic on Bishop Hill, however badly formed. But I do think to come onto this thread without making clear whether he himself thought IPCC SAR was mistaken for arguing that the hotspot is a anthropogenic signature was to be a bit economical with the er, courage of his convictions.
Mark Well
At the front of most cars is thing called a radiator which is a misnomer because if you do not drive forward fast enough or have fan it does not do much to cool your car engine. Also its been some time since PCs were cooled just by radiation from heat sinks. You have to have fan to convect the heat away.
What I am getting at is that convection is by far a more effective way to move thermal energy than radiative transfer. Just try soldering a joint outside on a windy day. Adding water with its latent heat of vaporisation to the mix makes convective cooling dramatically more effective. Some small air conditioners work by evaporating water off their condensers. Power stations get rid of huge amounts of energy by trickling water down cooling towers.
Radiative transfer and downwelling LWR is what gives us the blanket to make life possible on Earth. Convection and water vapour is what limits that warming. In my view the Clausius Clapeyron relationship of water vapour and temperature, far from leading to runaway warming, places a limit on water vapour enhancement by demanding ever more downwelling LWR for each temperature increment – if we assume constant relative humidity, as the IPCC does. If we add in the fourth power of the Stefan–Boltzmann law and the absorption saturation characteristics of greenhouse gases it seems logical to me that global warming is largely self limiting. See Bill Kininmonth on http://www.youtube.com/watch?v=1QJuUTal05k
David H, yes this message needs to be repeated as much as possible. The metal object full of pumped hot water that warms your room is also inappropriately named. Try holding your hand two feet to one side of it, then hold your hand two feet above it, and notice the difference.
Yet many climate scientists seem to believe that you can determine the temperature of the earth by doing a 'radiative calculation'. Worse still they talk of heat getting 'trapped' in the atmosphere by CO2. It's as if they've forgotten that hot air rises.
@ Richard Drake, Aug 19, 2013 at 4:28 PM :
Not 'alf! No worse than theirs, is it? :)
And at least Hampson made some sort of logical sense.
Aug 19, 2013 at 5:57 PM | David Holland
I think you are quite right. It would surprise me if evaporation and convection were not properly allowed for in the GCM programs. I do not know why they have to assume constant relative humidity. I should have thought it possible to compute it. The effect of water vapour on the equations in a radiation field is what I have been asking about.
The back-of-envelope calculations using the S-B law however are nothing like accurate enough. The Earth is warmer than it would be without an atmosphere, but the increase is much more than the advertised 33 deg K. Without an atmosphere, the Earth’s temperature would probably be more like that on the Moon, which has been measured. I don’t think the CO2 hypothesis can account for the warming which we actually observe.
Through a combination of natural laziness, insufficient time and lack of easily sourced material I do not know a lot about how the GCM’s actually work, but I have programmed versions of the turbulent NS equations. So I know how the equations are derived and what they contain and I should like to know how the computational climatologists cope with the radiation modification.
This is clearly not the same as the radiation effects about a re-entry vehicle, which are relevant at much, much higher temperatures, but are very important and usefully serve to allow the skin temperature to be considerably lower than otherwise would be the case.
I would like to see the differential equations derived by the control volume method and I would like to see how the low-temperature radiation phenomenon comes in when the "greenhouse gases" are present.
My suspicion is that climatologists do not modify the basic equations at all. I suspect that they just alter the boundary conditions. Would that be good enough? Probably not at all.
Thanks for the video reference. It looks good.
The ability of fanatics to seamlessly rationalize away inconvenient data is amazing.
In a modelling paper of a decade or two ago I distinctly recall Schmidt describing the hot spot as a "robust" feature of climate models.
here it is, Will:
Amplification of Surface Temperature Trends and Variability in the Tropical Atmosphere
B.D. Santer, ∗ T.M.L. Wigley, C. Mears, F.J. Wentz, S.A. Klein, D.J. Seidel, K.E. Taylor, P.W. Thorne, M.F. Wehner, P.J. Gleckler, J.S. Boyle, W.D. Collins, K.W. Dixon, C. Doutriaux, M. Free, Q. Fu, J.E. Hansen, G.S. Jones, R. Ruedy, T.R. Karl, J.R. Lanzante, G.A. Meehl, V. Ramaswamy, G. Russell, and G.A. Schmidt
Submitted to Science, May 13, 2005. Revised: July 19, 2005
http://www.osti.gov/energycitations/servlets/purl/881407-xk2Sdg/881407.pdf
(from the Abstract)
The month-to-month variability of tropical temperatures is larger in the troposphere than at the Earth’s surface. This amplification behavior is similar in a range of observations and climate model simulations, and is consistent with basic theory. On multi-decadal timescales, tropospheric amplification of surface warming is a robust feature of model simulations, but occurs in only one observational dataset. Other observations show weak or even negative amplification. These results suggest that either different physical mechanisms control amplification processes on monthly and decadal timescales, and models fail to capture such behavior, or (more plausibly) that residual errors in several observational datasets used here affect their representation of long-term trends.
(from the paper itself)
Tropospheric warming is a robust feature of climate model simulations driven by historical increases in greenhouse gases (1–3). Maximum warming is predicted to occur in the middle and upper tropical troposphere. Atmospheric temperature measurements from radiosondes also show warming of the tropical troposphere since the early 1960s (4–7), consistent with model results (8).
One can only imagine what Gavin will tell in the world in 2021.
So much for 'settled science' two words which I bet they wish they never used.
Dung, now I am on a PC that won't double-post...
I agree with all your posts (on this thread) except the one that says that downgrading old IPCC reports has any meaning.
The Team had already thrown out the IPCC reports back when the Climategate emails came.
But new IPCC reports must be taken seriously because if else, well, what?
Precautionary Principle.
That is why this line should be opposed. The fact that the Tropical Hotspot is a falsified is reason to not panic and follow the demands of the Precautionary Principle.