Friday, April 03, 2009

Reading Assignments

Rabett Run Labs has put up the beta version of our reply to G&T You can get it directly or on our web site. If you edit it, please turn on the show edits markup so we can merge your changes. If you have contributed (and the guilty know who they are) let Eli know you want to be included. Please include any affiliation that will not fire you if identified. There is one other piece being worked on, a meta-summary of how the article was constructed, which should be posted tonight.

Let it be so.

UPDATE: The article is quite long and not very snarky. If you want a short, and simple example of why as Gavin Schmidt says about G&T

It’s garbage. A ragbag of irrelevant physics strung together incoherently. For instance, apparently energy balance diagrams are wrong because they don’t look like Feynman diagrams and GCMs are wrong because they don’t solve Maxwell’s equations. Not even the most hardened contrarians are pushing this one…. - gavin
go here

A slightly lot shorter summary is here, a discussion of some of the problems with G&T are here and here, a discussion of the failures of the peer review system of which G&T are one is here and lots more at Rabett Run

25 comments:

Duae Quartunciae said...

I'll be making some minor edits to my stuff. What conventions would you like for formatting? If you stick with Microsoft word, then a simple set of styles for titles and main text would be good.

Do you have references for the backradiation spectrum in figures 7 and 8?. I propose to add a brief comment, and reference, for early measurement in 1954, using a pyrgeometer. I also have a reference to a text for architects and builders, which uses backradiation explicitly in consideration of effective cooling systems. It is: Givoni, Baruch, 1994. Passive Low Energy Cooling of Buildings, John Wiley and Sons, 1994
ISBN 0471284734, 272 pages. Chapter 4, on radiant cooling, considers the importance of backradiation. That's probably not worth adding, but it was a good reference when I was discussing this paper with an engineer who boasted about being pragmatic.

TimC said...

Eli,

It looks good. I am amazed that their arguments could be so off as to argue that heat flux can travel in only one direction from the hot to cold rather than that the net heat flux (incoming and outgoing must be from hot to cold) and that they could get published.

However, I believe it might be helpful, assuming this is directed towards an audience that does not necessarily have a background in physics (that is, those who might fall for such nonsense) to include a bit about how the physics underlying the greenhouse effect is basically the same as that which underlies lasers, microwave ovens, etc. Likewise, including one of those images of carbon dioxide at 8 km at 15 μm with the darker areas over the west and east coast of the United States might help if you were to include some explanation as to why it appears darker.

As for the pot with the boiling water, mentioning how much warmer your hand will feel a foot or so above the pot if there is water actually boiling away rather than if there were no water in there at all would be a good way of communicating what latent heat is and the fact that it is being transported away from the pot by non-radiative means.

Now it is of course possible that the audience you are directing this towards is technical -- but that they will need to be able to communicate many of the details to a non-technical audience -- in which case brief excursions into these sorts of explanations might help by suggesting to them how they might approach such topics with their audiences.

Cymraeg llygoden said...

Eli

If any part is to be submitted to a journal and is accepted for publication then it will likely undergo a reasonably proper copy edit, so there is no need for anyone to really waste their time on that aspect at this stage.

However, if most/all of this is ending up at ArXiv, then it could do with a copy edit once the technical issues have been resolved amongst the authors and reviewers. There are issues that could do with being attended to in this regard.

Perhaps you have this in hand. However, if not, then I'll gladly cast that copy editor's gaze over it if you wish (with tracked changes). Let me know. I'll keep my eye on this blog topic on and off for the next couple of weeks.

Cymraeg llygoden

Barton Paul Levenson said...

I've read it over superficially once so far, and it looks really good to me. I'd use 250 K and 288 K for the up-and-down diagram rather than 260 and 300, but that's a quibble.

Could this be published in the same journal that published G&T? That would be the proper place for it--assuming the editors don't turn it down out of some weird partisan bias, which perhaps explains why they published G&T in the first place.

Thomas Palm said...

As a blog post it would be fine, but I'd tone down the snarkiness if you want to publish it in a scientific journal. It's better to take the high ground, politely point out the errors and let the readers draw conclusions of what it says about the editorial policy that it was published.

Anonymous said...

I would second Thomas' plea to tone it down a bit.

Sometimes it's better to leave the obvious unsaid.

The people who understand the technical issues will insert their own snarky comments in their mind when they are reading it.

And the people who do not understand the technical issues might actually be turned off by the snark if they think it smacks of arrogance or even bias.

EliRabett said...

Guys, it's out there to be edited. Which means toning it down, etc.

EliRabett said...

Should add that we are working from a very beta draft.

chriscolose said...

I sent Eli an email full of grammaer/structure edits. Content looks good for the most part.

Marion Delgado said...

When you win the nobel peace prize for medicine in physics, all of us who are Reviewers of the G&T will share in it, and can henceforward call ourselves Nobel laureates.

I can tell already that my theory of Intelligent Clouding is just the tonic your report needs to gin up support for sound science.

Anonymous said...

Eli Rabett,

that looks "great". Reviewers will laugh. The best joke are figures 5 and 6 because this is sheer scientific nonsense.

As earlier debates in dot.earth of the NYT reflected, you are not able to understand what the second law of thermodynamics really means.

To criticize the figure 2 (13) is quite justified. Since this figure can be found in the textbook of Goody and Yung (1995), it is obvious that Bakan and Raschke (2002) did not cite the legend of that figure correctly. This figure is also misleading, first from an energetic point of view, second from a didactic point of view (see http://www.gi.alaska.edu/~kramm/climate/Planck_function1.pdf ).

Georg Hoffmann wrote that this figure illustrates Wien's displacement law. This is incorrect. Wien's displacement law from 1894 simply means

U(ny,T) = C ny^3 func(ny,T)

U(ny,T) is the spectral energy density, ny is the frequency, T is the abs. temperature, and C is a constant.

In younger textbooks, the relationship lambda x T = const. (lambda is the wavelength) is called Wien's displacement law, but this is not entirely correct. This relationship can be deduced from Wien's displacement law, even the relationship that the maximum of the func(ny,T) is proportional to T^5. I have all the relevant papers as electronic copies. I am willing to send it to you (or Arthur Smith because the papers are written in German) so that you can take a look into this paper

Figure 1 is interesting. In the January 2009 issue of Physics Today there was a diagram (p. 48) illustrating observations of the total solar irradiance (TSI). According to this diagram the TSI varies from 1373 W/m^2 (ERB/Nimbus 7) in 1979 to 1366 W/m^2 (ERBS) in 2003. What the authors of this paper did not show were the TIM data. TIM was launched in 2003. Its results are close to 1361 W/m^2. This means that the TSI-values observed have been changing by 12 W/m^2 within a period of 30 years. However, you are chatting about radiative equilibrium at the top of the atmosphere.

Best regards

Gerhard Kramm

Barton Paul Levenson said...

Dr. Kramm,

The fact that different satellites get slightly different readings for TSI does NOT mean TSI has taken on all those values. It means the satellites are calibrated differently or are experiencing different angle situations due to their differing orbits. Your comment is like saying that because KDKA in Pittsburgh measures the temperature one day at 12:00 noon as 13.2 C and WTAE measures it the same day as 14.7 C at 12:01, that the temperature jumped 1.5 C in Pittsburgh in one minute.

Anonymous said...

Barton Paul Levenson,

your instance has nothing to do with the observation of TSI. TSI observations are on a global scale, otherwise they would be senseless. That the results of satellite observations depend on the sensors used and their calibration techniques is well known. The fact, however, is that these observations are used to underline that a radiative equilibrium exists at the top of the atmosphere (TOA). In my opinion the uncertainty involved in satellite observations does not allow such an assumption on radiative equilibrium, when a change of observed TSI of about 12 W/m^2 during a period of 30 years is documented. It might be roughly fulfilled, but there are various uncertainties. To me, it was arkward not to see TIM data in that figure even though TIM was launched in 2003.

Here is another example:

If radiative equilibrium exists at the TOA and the earth's surface becomes warmer, let me say by 3 Kelvin, then the radiative equilibrium would quickly be disturbed. Since infrared radiation can be transferred through the atmospheric window without strong attenuation (only the 9.6 my band of ozone is acting) we will have an increase of infrared radiation at the TOA. To balance this increase it is necessary that either in the other spectral ranges the IR radiation is lowering or the outgoing solar radiation is lowering or both. To analyze such effects is not so simple. Our atmosphere is a very complex and non-linear system.

Best regards

Gerhard Kramm

Barton Paul Levenson said...

Dr. Kramm,

You appear to have responded to my post without reading it, or at least without understanding it. Otherwise you would not persist in your "TSI changed 12 W/m2 in 30 years" nonsense. Unless THE SAME SATELLITE measures such a leap, the leap did not take place. You're comparing apples and oranges, as we say in the US. TSI has not jumped 12 W/m2 in 30 years. Period.

Anonymous said...

Barton Paul Levenson,

I did not state that the TSI has absolutely changed by 12 W/m^2 during the last 30 years. This change is, we must assume, the result of the use of different sensors and calibration procedures.

If it is so, then one cannot use such satellite observations for supporting that the radiative equilibrium at the top of the atmosphere is real.

Gerhard Kramm

Duae Quartunciae said...

What Kramm actually said above is:
"This means that the TSI-values observed have been changing by 12 W/m^2 within a period of 30 years."

Now perhaps that's just poor phrasing, and he really meant that the numbers don't give an accurate number for observed TSI.

But even being generous about language use, it still sticks out on its technical merits as an irrelevant red herring.

The presumption of energy balance is NOT based on TSI measurements at all. Never has been. It's based on the first law of thermodynamics; conservation of energy. The idea of energy balance has been around long before TSI was able to be measured above the atmosphere.

Kramm was the one who introduced TSI measurements here, apparently trying to discredit discussions about energy balance. That's stupid. There's no other word for it. It's an ignorant distraction by someone who is either clueless, or dishonest, or malicious.

Moving apart from this nonsense, what is more interesting is that evidence at present does suggest a small imbalance at the top of the atmosphere, and this appears in the G&T response, as part of figure 1.

The imbalance at the top of the atmosphere is matched entirely by energy absorbed somewhere within the Earth. It HAS to be, by simple undergraduate physics, to give an overall energy balance. In fact, it shows up as a flux of heat energy into the oceans, of about 1 W/m^2, as the oceans increase in temperature. That is: they are warming. Quantifying that imbalance is hard, but the underlying principle of energy balance is bedrock high school level physics that is used to relate all the various quantities we may try to observe.

Anonymous said...

Duae,

do you know any governing equation that demands a radiative equilibrium at the top of the atmosphere?

The observational material does not allow to give evidence that such a radiative equilibrium is real.

In the case of a sound thermodynamic system the second law of thermodynamics only demands that the entropy export must be equal or larger than the entropy production.

Gerhard Kramm

Anonymous said...

Eli Rabett and the Bunnies

In the textbook of Liou (2002, An Introduction to Atmospheric Radiation) there is a pair of equations (8.3.5) and (8.3.6) for the surface temperature and the atmospheric temperature. This pair of equations is based even on a formulation using the power law of Stefan and Boltzmann. Based on this pair of equations one can also show that the atmosphere may cause a "cooling effect" because it provides temperatures even higher than 288 K, the value of the globally averaged near-surface temperature.

Any reviewer will laugh about such an attempt.

Gerhard Kramm

Duae Quartunciae said...

Dr Kramm, as I explain just above, the equation we all know and love is conservation of energy. I did not mention the second law. I explicitly invoked first law.

Applied to the radiative balance at the top of the atmosphere, it means that any IMBALANCE is taken up as energy being absorbed or lost within the Earth. That's also explicit in what I said, and in the G&T response, and in the energy flow diagram used.

The estimated imbalance at present is given in figure 1 as 0.9 W/m^2, and that matches a flow of energy into warming oceans. There's uncertainty in that number (a recently published estimate was 0.85 +/- 0.15) but there's no physical possibility at all of it being substantially larger, and certainly not commensurate with the 12W/m^2 discrepancies you've cited for raw TSI measurements by different satellites.

We know this, because we know about energy balance. This is is known elementary physics from long before TSI was ever measured in space. Your invocation of uncertainty in TSI measurements was an irrelevant distraction.

There is an necessary exact balance between the flows at the top of the atmosphere, and energy being stored within the Earth. There is a necessary approximate balance at the top of the atmosphere because of the physical limits on the rate at which the Earth can take up energy.

I address these remarks to you as a matter of courtesy. But I am not aiming to persuade you. I no longer think that is possible, not even for trivial points of mathematics, where your claims of mathematical errors are just as vacuous.

I don't understand why or how a professional scientist makes such nonsensical objections; but it happens from time to time. Somehow a legitimately qualified scientist ends up as an irrelevant crank on some field, and nothing will ever persuade them of their foolishness. The main thing is simply to explain where their remarks fail, for the record and for the use of any interested readers who might care.

Sincerely yours, etc.

Anonymous said...

Dear Duae,

please do me a favor, read textbooks on atmosphere energetics (van Mieghem, Wiin-Nielsen etc.) or physics of climate (Peixoto and Oort), perhaps you will learn what conservation of energy does mean.

Gerhard Kramm

EliRabett said...

Dear Gerhard,

It is pretty hard to come up with an emptier statement than your last bunch. Right up there with the explain the universe, give two examples type of G&T reference that Joerg noted. In other words no there, there, so no reply needed

If Eli were a mean bunny, he would point out that you are the Dunning Kruger poster kid, you know, the one you see on a milk carton (Have you seen this child? He's lost his brains). But have a nice holiday.

Duae Quartunciae said...

Ignoring more irrelevancies (I've read the books, I've taught the physics) let's move on.

(A) Professor Liou's energy balance model for a single slab atmosphere

In the comment at 11.41 am just 4 steps above, Dr Kramm invokes "An Introduction to Atmospheric Radiation", by Kou-Nan Liou (Academic Press, 2002). I have on hand the previous edition (1980), and google books gives extracts of the updated edition. Professor Liou is active in research on climate modeling, greenhouse warming, remote sensing, and radiative transfer. He's an excellent antidote to Kramm's nonsense.

Dr Kramm mentions equations 8.3.5 and 8.3.6.

These equations are derived from two energy balance equations 8.3.3 and 8.3.4, for a simple two layer radiative equilibrium model, described in figure 8.8, with a blackbody surface and a single slab atmosphere. Radiation is divided into solar shortwave and thermal IR. The atmosphere has reflectivity r for SW wavelengths (albedo). It has SW absorptivity A, and IR emissivity ε.

To make ASCII representation convenient, I use S for surface temperature, and T for atmospheric temperature. These are T and T_a in the book. To avoid the need for greek letters, I use "e" for emissivity "ε", and "s" for the Stefan-Boltzmann constant.

Equation 8.3.3 is the energy balance at top of atmosphere. Incoming solar radiation is Q, and reflected outgoing SW is r.Q. There is no IR input. IR output is e.s.T^4 (thermal emission from the atmosphere) and (1-e).s.S^4 (the portion of surface emission transmitted). The TOA energy balance equation is thus:
Q.(1-r) – e.s.T^4 – (1-e).s.S^4 = 0

Equation 8.3.4 is the energy balance at surface. Solar input is (1-A-r).Q, without the reflected fraction r, or absorbed fraction A. The IR input is atmospheric backradiation e.s.T^4 (the same that G&T don't believe in). The IR output is s.S^4, which is assumes blackbody thermal emission.
Q(1-r-A) + e.s.T^4 – s.S^4 = 0

Equations 8.3.5 and 8.3.6 are obtained by solving for T and S.
(Eq 8.3.5) S^4 = Q.[2.(1-r)-A]/[s.(2-e)]
(Eq 8.3.6) T^4 = Q.[A+e.(1-r-A)]/[s.e.(2-e)]
It is comical… and a bit nauseating… to see Dr Kramm invoking a simple energy balance model here while at the same time disparaging the notion when used by others.

That's the first point. Dr Kramm is a hypocrite on the matter of energy balance.

(B) Heating top down, rather than bottom up

There's more. In the comment above at 11:41 AM Dr Kramm says on his own behalf: " Based on this pair of equations one can also show that the atmosphere may cause a "cooling effect" because it provides temperatures even higher than 288 K, the value of the globally averaged near-surface temperature."

Now what the heck is he thinking? Dr Kramm is legitimately an expert in atmospheric physics, which makes his comments here all the more incomprehensible. I think he is obscure quite deliberately; clarity does not work in his favour! Nevertheless there is a real effect, a reversal of the usual greenhouse effect, that can be described using Professor Liou's model. If we spell it out, the irrelevance becomes obvious.

Let me explain.

Dr Kramm speaks of the atmosphere being at higher temperatures than the surface. In reality, the only way we get atmospheric temperatures higher than the surface is an "inversion", which can occur near the surface at night or as an unstable layer of cold air in unusual weather conditions. This model can't represent an inversion, because the atmosphere is a single slab, and the inversion does not extend to the top of the atmosphere.

We can still get a meaningful correspondence with the model by taking a portion of the atmosphere with a stable negative lapse rate. We've got that on Earth, in the stratosphere; except that the temperatures are still well below surface temperatures. You can get a correspondence with Professor Liou's model by substituting the tropopause for the actual surface. The stratosphere has a negative lapse rate, with temperature increasing as you move up from the tropopause.

With a bit of straightforward algebra applied to equations 8.3.5 and 8.3.6, you can show that T > S iff and only if e < A/(1-r-A). That is, the emissivity imputed to the atmosphere, as a slab, must be less than the ratio of SW absorbed in the atmosphere to what is absorbed at the surface. This means the atmosphere is heated mainly by solar input, and the surface is then heated mainly from the atmosphere. Something like this occurs around the ozone layer of our stratosphere, except that it doesn't actually make much difference for the surface. It means there is a region well above the tropopause that is heated by the Sun, and that gives a small flux of IR radiation coming downwards.

The stratosphere also involves temperatures well below 288K, but it's the best example of a stable situation in our own atmosphere where the heating is top down, rather than bottom up.

Nick Xylas said...

I'm a complete layman, so forgive me if this question sounds ignorant, but is the International Journal of Modern Physics a bona fide scientific journal, or one of these fake journals put out by the denial industry? If it's real, how did this paper ever pass peer review if it's as nonsensical as it appears?

EliRabett said...

That is a good question. IJMPB is a condensed matter (that means solid state, eg metals, semiconductors, magnetics, etc) journal. None of the editors or the editorial board appear (Eli checked last night) to have ever published anything about atmospheric sciences or anything related. The journal (and the other IJMP) journals are oriented towards China and India (there is good physics there), but this is not a major journal. Go to their website and poke around.

G&T has been kicking around on arXiv (a place where you can put pretty much anything in a scientific wrapper) for a a long time. In any case, what appears to have happened in that one of the Editors, Schommers, decided to publish it. It is nonsense.

EliRabett said...

Nick, thanks for the motivation. Eli found an interesting tool for ranking journals (this matters to academics)
http://www.eigenfactor.org

FWIW IJMPB ranks about 6000 out of 8000.