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Please, show us your code

Filed under: — rasmus @ 17 December 2009

The 1991 Science paper by Friis-Christensen & Lassen, work by Henrik Svensmark (Physical Review Letters), and calculations done by Scafetta & West (in the journals Geophysical Research Letters, Journal of Geophysical Research, and Physics Today) have inspired the idea that the recent warming is due to changes in the sun, rather than greenhouse gases.

We have discussed these papers before here on RealClimate (here, here, and here), and I think it’s fair to say that these studies have been fairly influential one way or the other. But has anybody ever seen the details of the methods used, or the data? I believe that a full disclosure of their codes and data would really boost the confidence in their work, if they were sound. So if they believe so strongly that their work is solid, why not more transparency?

There is a recent story in the British paper The Independent, where Friis-Christensen and Svensmark responded to the criticism forwarded by Peter Laut (here). All this would perhaps be unnecessary if they had disclosed their codes and data.

Gavin and I published a paper in Journal of Geophysical Research, where we tested the general approach used by Scafetta & West, and tried to repeat their analysis. We were up-front about our lack of success in a 100% replication of their work, but we argue that the any pronounced effect – as claimed by Scafetta & West – should be detectable even if the set-up is not 100% identical.

However, Scafetta does not accept our analysis and has criticized me for lacking knowledge about wavelet analysis – he tells me to read the text books. So I asked him to post his code openly on the Internet so that others could repeat our test with their code. That should settle our controversy.

After repeated requests, he told me that he doesn’t really understand why I’m not able to write my own program to reproduce the calculations (actually, I did in the paper together with Gavin, but Scafetta wouldn’t accept our analysis), and keeps insulting me by telling me to take a course on wavelet analysis. Furthermore, he stated that there “are several other and even more serious problems” in our work. I figure then that the easiest way to get to the bottom of this issue it to repeat our tests with his code.

A replication in general doesn’t require full disclosure of source code because the description in the paper should be sufficient, though in this case it clearly wasn’t. So to both save having us do it again and perhaps miss some other little detail – in addition to using an algorithm that Scafetta is happy with – it’s worth getting the code with which to validate our efforts.

It should be a common courtesy to provide methods requested by other scientists in order to speedily get to the essence of the issue, and not to waste time with the minutiae of which year is picked to end the analysis.

The reason why Gavin and I were not able to repeat Scafetta’s analysis in exact details is that his papers didn’t disclose all the necessary details. The first point he raised was that we used periodic instead of reflection boundaries. The fact that the paper referred to the expression ’1/2 A sin (2 pi t)’ to describe the temperatures or solar forcing would normally suggest that they used periodic rather than reflection boundaries. There was no information in the paper about reflection boundary. But this is no big deal, as we have subsequently repeated the analysis with reflection boundary, and that doesn’t alter our conclusions.

After further communication, we found out that Scafetta re-sampled the data in such a way that the center of the wavelet band pass filter was located exactly on the 11 and 22 year solar cycles, which were the frequencies of interest. He also informed me that a reasonable choice of the year when the reflection boudary was made should be the year 2002-3 when the sun experienced a maximum for both the 11 and 22 year cycles. This information was not provided in the papers.

I’m no psychic, so I couldn’t have guessed that all this was needed to reproduce his result. But since Scafetta has lost faith in my ability to repeat his work, I think it’s even a greater reason to disclose his code so that others can have a go.

For the record, we did not just use wavelets to filter the data – we obtained the same conclusion with an ordinary band-pass filter.

233 Responses to “Please, show us your code”

  1. 151
    Mike W says:

    Ah what the hell:)

    Ok, at “room” temperatures “most” of the molecules won’t be moving fast enough to reach the threshold energies required to excite a ro-vibrational mode in a molecule during a collision. This is what we mean when we say the rotational and vibrational degrees of freedom are frozen out. That makes perfect sense if the collisions involve molecules in their ro-vib ground states, which they do for the most part at room temperature. As Ray points out, exciting a gas with IR effectively sidesteps equipartition, albeit only locally and briefly.

    Are we saying that excited CO2 molecules have to lose energy in collisions and they can’t gain energy? Fully accept that the ro-vib energy is quantized, but the collisional broadening profiles I’ve seen seem to indicate that excited CO2 molecules can gain energy during collisions just as easily as they lose it. Yet a lot of the advice I’ve had (appreciated by the way) suggests it’s largely a one-way process of de-excitation.

    It’s definitely very hard to collisionaly excite a CO2 molecule from its ground state at room temperatures, no question. But do excited CO2 molecules really only lose energy in collisions, is that what is being implied?

    At the moment, I can’t make this sit straight with what I think I know about collisional broadening (impact pressure broadening).

    Should also mention that I appreciate CO2 is going to collide with N2, O2, the works.

  2. 152
    Terry says:

    I welcome the new order of transparency and providing code for others to examine. Personally when I review scientific work by others I try to obtain the result by my own alternative methods. If that fails then I ask for the code or the calculation detail. This is precisely the methodology explained by Gavin and Eric.
    But in this new order of rapid exchange of information with the ability of other scientifically minded persons who may or may not be in the mainstream organisations to critically review others work, it seems to me that disclosure should be the norm from now on. The days of waiting 6 to 12 months or more for review or replication in traditional peer reviewed journals are numbered and I for one think this is a good thing. The advantages are obvious. Better and more comprehensive reviews are possible by persons who have skills that are not the core expertise of the authors can provide valuable input. The skills of statisticians comes immediately to mind when dealing with earth sciences, when the principal scientist is way more interested in the science and does not appreciate the finer points of the statistical analysis he/she is using. The old phrase “publish or perish” certainly now has a new meaning. We live in interesting times and lets hope that disclosure becomes more of the norm from now on in all scientific endeavors.

  3. 153
    Silk says:

    “I am simply asking Gavin (notice Silk has committed you on this) whether you are 100% sure that the solar radiation forcing has been accounted for and appropriately discounted given that we are not 100% sure about absorption rates and other potential cyclical factors they may have an impact by increased radiation.”

    Who do you think I am? Gavin’s boss?

    Who do you think /you/ are? You want answers? Read the papers, like anyone else.

    “I remain unconvinced that the amount of solar/magnetic radiation changing by 1% does not have a huge impact on thermodynamic exchanges in the atmosphere and terra firma.”

    Bully for you. Your opinions, one way or the other, have no impact on science, or reality.

    READ the IPCC report if you care about it so much. And if that doesn’t answer all your questions READ the references contained therein.

  4. 154
    Dan Hughes says:


    I’ve been sharing data and code since the early 1970s. I find the procedure to be the most simple aspect of my work.

  5. 155

    ADR–No, it’s 0.0388% CO2. 388 parts per million by volume.

  6. 156
    Ray Ladbury says:

    Mike W. says “Are we saying that excited CO2 molecules have to lose energy in collisions and they can’t gain energy?”

    Of course not! It is simply that their constituent atoms are moving a lot faster than the typical atom (remember that a vibrational energy level has both kinetic and potential energy). Most certainly you can wind up with a spread of energies as you distort the bonds of the CO2 molecule in collisions.

    The de-excitation process is quantized, but it is quantized based on the configuration of the CO2 molecule at the time of de-excitation (distorted bonds and all). You can visualize collisional de-excitation as an almost classical process, where an oxyten atom in the CO2 molecule collides with an N2 molecule and imparts its energy to the N2 moleculd–it’s just that the energy imparted is quantized.

  7. 157

    dhogaza says:
    18 December 2009 at 6:39 PM

    “Do Roy Spencer and John Christy make the source code used to create the UAH MSU temperature reconstructions public?”

    Why don’t you ask them? I know that John Christy is very approachable. He was kind enough to reply to one of my emails.

  8. 158
    Completely Fed Up says:

    Mike W, such collisions between molecules in an excited state are inelastic.

    The extra energy comes from or disappears into non-kinetic sources/sinks.

    VERY early A-level (Higher) Physics.

    Read up on Equipartition of energy and learn some physics before questioning the physics, M’kay?

  9. 159
    Phil. Felton says:

    Ray Ladbury says:
    18 December 2009 at 9:07 PM
    Phil Felton says, “Figured there would have to be an asymmetry for it to work, the message I’m taking away is that it is “easier” for vibration to “become” translational energy than it is for translational energy to become vibrational energy.”

    The asymmetry is in the energies. Few gas molecules in the atmosphere (~1% or so I think) have sufficient energy to excite the vibrational mode of CO2. When such a mode is excited by an IR photon, the vibrational mode has an excess of energy compared to what would be expected via equipartition. As such it will tend to de-excite collisionally–and the long life of the vibrational state means it has plenty of time to do so.

    I agree Ray, the quote attributed to me was actually from MikeW, for some reason only the outer part of his post was italicized.

  10. 160
    Completely Fed Up says:

    RS: “Why don’t you ask them?”

    So the answer is “no”, then.

    If you have to ask if they’ve even released the data and source, then it’s not being made available, is it. Else this would be possible to find out, just like the GISS ModelE code is made available which can be found with a suitable google.

    PS why didn’t you ever say that when the thousands of dittos turned up asking where the source code for these computer models were?

    If you were a little less partisan, you’d appear a little less biased against AGW.

  11. 161
    Completely Fed Up says:

    “Dan Hughes says:
    19 December 2009 at 6:35 AM


    I’ve been sharing data and code since the early 1970s.”

    I would suspect that most/many scientists from the CRU et al would prefer not to have to worry about copyrights and ownership of data too. However, they could not do that since almost every government in the world requires that any possible money that can be made by a department looking at the weather be persued.

    If any one NMO gave away their data freely they would be slapped down for wasting an opportunity to reduce costs by having a commercial center (you can go to the Met Office website for the UK Met Office and see that they have a commercial arm). And undermining that would be a SERIOUS offence.

    At least now some of the hassle of complying with copyrights and having to “monetize” all products however meanly for weather data reduces workload and if this undermines the commercial arm, they cannot be censured for it: it is the DEMAND of the Vocal Minority that this be so.

    Of course, loss of licensing revenue means taxes will have to go up, but if the Vocal Minority complain, just point them to the accusations and demands for open and freely accessible data and they (should) accede.

  12. 162
    Hank Roberts says:

    Pardon the digression, but: for anything, before you drink the permitted amount, do check when that drinking water standard was set, then look for research since that date–and think for yourself. That will put you well (ahem) ahead of the regulatory process.

    “It’s a poor sort of memory that only works backwards.”
    More recent information is always available.

  13. 163
    J. Bob says:

    #154, You are right on sharing code. It is interesting, how easy it is for others to find errors. One tends to have to much “tunnel vision” in coding, ( i.e. in part such as making sure zero’s and Oh’s are separate), programming and analysis.

    That has served me well since the early 60′s

  14. 164
    JohnV says:

    I spend too much time in the “angry echo chamber” where I keep hearing that the code and data for key paleo-climatology papers has not been released. If that’s true, is there a justification? Thanks.

    [Response: It's not true, in general.--eric]

  15. 165
  16. 166
    Completely Fed Up says:

    “#154, You are right on sharing code. It is interesting, how easy it is for others to find errors. ”

    Just as people can make mistakes in filling in their tax forms.

    So, can we have your tax returns for the past 20 years?

    So someone codes up

    FLOAT a,b,c;

    And you point out there’s a bug there: divide by zero.

    But the person writing this code knows that this doesn’t matter in the dataset they have.

    It’s surprising how easy it is to find errors in someone’s argument, isn’t it.

  17. 167
    Completely Fed Up says:

    PS Having found an error, I suppose we have to consider everything J Bob says as wrong without working out if he is.

    This, after all, is how Climategate has been handled by the rightwingnuts.

  18. 168
    dhogaza says:

    I would suspect that most/many scientists from the CRU et al would prefer not to have to worry about copyrights and ownership of data too. However, they could not do that since almost every government in the world requires that any possible money that can be made by a department looking at the weather be persued.

    A key thing I think the denialists purposefully ignore is that the decision isn’t likely to be in the hands of the scientists doing the work.

    The UK Met service is charged with providing services for fees, some of which are based on models run on UK Met-owned computers. They use the same atmospheric model for generating various near-term forecasts as is used in the more complex fully-coupled climate model, for instance. One can see that the powers that be might not agree to model source being released because of the potential of undercutting the sale of such services.

    If you don’t like this situation, go after the politicians who require them to make money where possible, not the scientists who, after all, are mere employees and aren’t in charge.

  19. 169
    Edward Greisch says:

    Wavelets are what I would call an “advanced” subject. I didn’t take that course yet. It could require several courses. From what I know of other transforms involving trig functions, I am not surprised that a problem could arise somewhere and be hard to find or easy to overlook. Weird things happen in that kind of process. From what I know about software, the problem could take nearly forever to find. The problem could be in the platform used rather than the code written by the scientist. Who knows? The publications mentioned never show enough steps for me to follow so I quit trying a long time ago. I wish they would all show more of the steps.
    Scafetta is apparently a wavelet analysis wizard, but my reaction is that everybody could use all the help available to check that computation. Why withhold code?

  20. 170
    lgp says:

    To paraphrase Eric and his typical, aloof RC response,

    “Try reading the post again, slowly. What they did is what they said we did, plain and simple. … You are really trying hard to find fault where there isn’t any.”

  21. 171
    Rod B says:

    BTW, I meant to say mulit “millions” as the number of collisions per second in my #67. Though some have estimated in the billions, and others here probably know better than I.

  22. 172
    Eli Rabett says:

    Coming back to this a bit late, excited molecules can gain energy vibrational energy by collision, it is just that the probability is low, there are a lot fewer vibrationally excited molecules than unexcited ones, there are a lot fewer collisions that have the same or higher energy needed to excite a further vibrational quantum.

    Oh, and btw, a nice example of using photon momentum is cooling atoms to reach Bose-Einstein condensation (see the Wikipedia for more detail)

  23. 173
    Rod B says:

    I might disagree with Ray (148) on the number of gas molecules that can excite a vibration state. But I’m not knowledgeable enough (too lazy — and he is undoubtedly close) and his basic point is valid, and is why the vibration-to-translation collisional exchange is far more plentiful than translation to vibration. One could find the number by using the gas laws and the boltzman distribution.

  24. 174
    Rod B says:

    Mike W (151), CO2 can and does pick up translation energy through collisions. Whether it de-excites collisionally or through emission depends on the Q-M probabilities of maintaining the excited state compared to the probability of collision which depends mainly on the molecular density of the gas. That probability is very high at low altitudes (high pressure), not so much in the upper stratosphere.

  25. 175
    Geoff Wexler says:

    Re: #69 Ely
    Are you sure about your remark about the vibrating mode with the symmetric stretch? Unless symmetry is broken somehow, I don’t see how electronic charge will be transferred. The charge will not know which way to go. In that case there will be no dipole moment and no interaction with the vibrating electric field carried by the photon, at least not in first order. Of course symmetry could be broken if the CO2 happened to be colliding with another molecule of something (pressure broadening) If this wrong , how?

    and Re: Mike W.
    (Just one more comment to this sub-thread). This is how I think about it.
    Imagine a little wall surrounding a few excited vibrating CO2 molecules and some N2 and O2. This is an artificial construct. To start with this little system would not be in statistical equilibrium. As a crude approximation , it could be considered as a mixture of air at one temperature and CO2 at a slightly higher one i.e a “hot CO2 regime”. (This is only rough terminology because by ‘hot’ I am referring to the population of the vibrational modes). As you will see this is a fiction because it is statistically highly unstable.

    According to the second law of thermodynamics the contents will share energy until the entropy is maximised. The final equilibirum condition is characterised by a single temperature which determines the relative occupation of the translational and vibrational energies of the CO2, O2 and N2 as well as the infra-red modes. It will however take a certain time to reach that equilibrium. Not very long , unless the pressure is extremely low.

    In practice you don’t usually need the wall, I only introduced it to suppress interaction with the rest of the world. This will make a small difference (assumption) but not much. This is a way that we can think about local thermodyamic equilibrium in a non equilibrium problem. Without the wall, there is no overal thermodynamic equilibrium because there is a temperature gradient and heat transfer. To be rigorous, this is now irreversible thermodynamics (another subject) because entropy is being created. If you were being really fussy you could argue that the concept of temperature was no longer valid. But usually there is no reason to be so fussy because the rate of collisions is so high (except at very low pressures). Thus the “local thermodynamic equilibrium approximation” is an excellent one and every point of the gas has a definite temperature, the same for O2,N2, CO2, the same for the vibrational and translational modes.

  26. 176
    Edward Greisch says:

    Woops! Scafetta can’t show you his code if he doesn’t have any! If the sun is obviously NOT THE PROBLEM looking at the raw data, wavelets analysis can’t make it into a problem! Scafetta is bluffing. We have known for a long time that the sun is NOT the cause of the climate change that is going on now. The sun is having a quiet period, a time out. It is time to call Scafetta’s bluff. Don’t let him play a psychological game on you. You, Rasmus, are not the dummy, but you are the object of a joke. The joke ends now. Rasmus gets the last laugh.
    Here is another reason for open code: You have to write code before you can publish it. You can’t publish unwritten code.

  27. 177
    Ray Ladbury says:

    Rod B., feel free to check my math. It’s not really difficult–just plug the vibrational energy and temperature into the Arrhenius eqation. Nothing magic. If I made a boo-boo, I’d be happpy for you to point it out.

  28. 178
    Mike W says:

    Completely Fed Up said “Read up on Equipartition of energy and learn some physics before questioning the physics, M’kay?”

    Enjoy stifling the intellectual curiosity of others? Can’t say that I’m that emotionally invested in it.

    I think you believe I’m attempting to challenge or re-invent the body of knowledge on radiative transfer, not so. I’m trying to cultivate a reasonably detailed and coherent understanding of how the radiated energy gets into the system and how its conserved and distributed, a week ago I didn’t even know the latter was called equipartition.

    In #151 I clearly consider the effects of equipartition, I go on to describe the dissonance I have with this new concept and my previous understanding. I’m not challenging it, I’m saying “why is it this way, and not another way?”.

    I am actually consulting the textbooks on Physical Chemistry and Atmospheric Radiation before I go running my mouth. Even then the textbooks come up short on answering these kinds of questions in a lucid way. RC gives me unique access to experts that I just can’t get any other way…I can’t believe they give this stuff away for free.

    FWIW, I’m now pretty comfortable with the idea that de-excitation by collision will be predominant at the low temperatures and higher pressures found near the surface. Radiative energy gets into the gas and excites a number of CO2 molecules, the gas is at that moment in (slight) disagreement with the distribution of energy predicted by equipartition (for a gas with that temperature and pressure) but the system quickly acts through collisional de-excitation to normalize the distribution of energy in a manner consistent with equipartition. By jove indeed.

    Don’t bully or belittle me, it’s unnecessary and unpleasant.

    Your loving layman, Mike W.

  29. 179
    David Weisman says:

    Did Scafetta & West fail to use the most current available information in their analysis? I’ve seen that claim, though not here.

  30. 180
    Completely Fed Up says:

    Geoff, #175, there IS a difference if you have a molecule with two different atoms. CO for example. The electron would spend longer at the Oxygen side than the Carbon side and increased separation would cause a dipole change: the O atom becomes more negative.

    If I’m remembering my school physics properly. We weren’t supposed to hear that but someone in class asked why O2 wasn’t affected.

  31. 181
  32. 182
    Garrett says:

    #151 Nu-2 (bending) and Nu-3 (asymmetric stretching) modes of CO2 are EXTREMELY IR active. The dipole moment
    comes from the vibrational motion of the molecule. The following links will help deniers learn about how
    infrared absorption works. (see page 5)

  33. 183
    Martin Vermeer says:

    Mike W, never mind CFU. I suspect it’s our old friend Mark — never mind him. Enjoy discovery!

  34. 184
    Garrett says:

    And who can forget the ATMOS/ATLAS missions:

    I remember working on the ATMOS data, this instrument was so accurate that we could measure vertical
    wind speeds by measuring Doppler shifts in the CO2 absorption lines all the way up to 120 km
    and were able to measure atmospheric tides (driven by peridic heating and cooling on the lower atmosphere and stratosphere). And this was way back in 1985!

  35. 185
    Jason says:

    I was glad to see most of the skeptical websites join you in your call for publicly releasing the code.

    As Rasmus was no doubt aware when he wrote this post, there is a long history of skeptics attempting to replicate the work of real climate contributors, only to be told that their replication is different from the original in some subtle way, not easily discernible from the original paper.

    Although you again say that public availability of the code is not necessary for replication (and I can agree with that) can we now also agree that publicly available code is a good idea because:

    1. it makes replication simpler

    2. it provides a far more precise specification of methodology than is possible using just the original paper and their SI

    3. it enables, where replications differ, a precise understanding of the reasons behind the difference

    4. it eliminates some of the suspicion by skeptics [which, in the case of Scafetta, means rasmus and gavin] that errors or impropriety affected the results

    5. it eliminates _all_ of the suspicion by skeptics that the code is being hidden in an effort to avoid detection of errors and/or improprieties

    It is difficult for me to imagine a scenario in which the public availability of all code and data used in refereed papers would not be a change for the better.

    [Response: This is probably a good place to state unequivocally that neither Rasmus nor myself think that there are any errors or impropriety in any of the code Dr. Scafetta uses. The scientific issue we are exploring is whether his precise methodology is robust to noise and co-linearity of other forcings, not whether he has made an error in his coding. It is precisely because of this automatic presumption that a request for clarification of details is because of a lack of trust in a scientist's integrity that there is resistance to these requests. No-one will take time out of their day to deal with someone who doesn't believe a word they say. The conviction that some contrarians have, that 'errors' and 'impropriety' exist that will somehow invalidate dozens of lines of evidence, made and replicated by a multitude of groups across the world is simply a fallacy - albeit one that seems widespread. Science needs transparency and communications in order to more efficiently work out what is going on in the real world, it has nothing to do with appeasing conspiracy theorists (who will not be appeased in any case). - gavin]

  36. 186
    Geoff Wexler says:

    Re :#180
    Of course; that was the point I was making to Ely. Symmetry or lack of is at the root of many or most things, and spectroscopy is an excellent example. Guess: I should imagine that HF, HCl,…. would make excellent greenhouse gases.

  37. 187
    Completely Fed Up says:

    One thing to remember is that there’s a lot less energy required to make a ruler go twang than to make it stretch.

    If your stretching of CO bond requires 1eV energies, you’re not going to manage it with IR at 1meV.

    And though you may be able to make it spin along another axis, that needs more energy too.

    Therefore Triatomic molecules especially are good absorbers in IR.

    Polyatomic molecules tend to have a lot more possible ways to wobble and these are often good at absorbing microwaves.

  38. 188
    Completely Fed Up says:

    “Enjoy stifling the intellectual curiosity of others?”

    Quite the opposite. I’d like you to go off and read about stuff rather than pop along to a website and get someone to tutor you for free.

    Especially when you’ve seem to be recalcitrant to take the information given so far.

  39. 189
    Completely Fed Up says:

    re 173, however if you have a three-body collision vibration is entirely possible. Which extracts its energy from translational kinetic energy.

    Also somewhat true at specific energies (like a string picking up the harmonic of another string being plucked nearby).

  40. 190
    Jason says:

    Re: Gavin’s comment to my #185:

    1. I agree that it is not the goal of science to appease “conspiracy theorists”.

    I hope that Real Climate can agree that there are many individuals who are skeptical of Real Climate papers who are _not_ conspiracy theorists.

    2. I certainly did not mean to imply that Gavin and Rasmus “think that there are any errors or impropriety in any of the code Dr. Scafetta uses.” I am not aware of them making any comments to that effect.

    My mentioning them specifically, was to clarify my use of the term “skeptic” as meaning those who are skeptical of the results in a particular paper (as opposed to those who are skeptical of Global Warming).

  41. 191
    Rod B says:

    A short comment on part of the so-called climategate. As I, a skeptic, said before, I think the strong push for full public release of all data and its manipulation is a pipe dream for the vast majority of the folks demanding it. From a purely practical viewpoint, with a few notable exceptions, we’d be like the dog that finally caught the truck. There is nothing we could do with it other than browse for some part that looks funny (whether we understand it or not) and that might make a good show — one of the valid reasons Gavin demurred in #185. I do not go as far to believe there is nothing wrong, untoward or that impropriety does not exist. I think it very well might (though the level that indicates this is nowhere close to some “smoking gun,” IMO) — or might not. But there has to be some other way to get an independent credible assessment. I would suggest the scientists have to come up with some agreeable method because, maybe through no fault of your own, and like it or not, you all have a public relations tiger by the tail.

  42. 192
    Rod B says:

    Completely Fed Up (187), a minor point, but I thought molecules absorbed IR because they have a polar moment, not because some wiggle better.

  43. 193
    Boris Tabaksplatt says:

    I think it’s good that the UK Met Office has decided to release as much of the data as possible to public access. Now, many people like myself are reconstructing regional trends, and starting to understand the difficulties people at the CRU had when trying to use the same poor quality and patchy data to build up a global picture.

    It’s a shame the raw station data isn’t available yet, but once this is published the original work can then be confirmed or not and an end put to the AGW debate once and for all.

    [Response: Wanna bet? - gavin]

  44. 194
    Garrett says:

    re 173, however if you have a three-body collision vibration is entirely possible. Which extracts its energy from translational kinetic energy.

    Also somewhat true at specific energies (like a string picking up the harmonic of another string being plucked nearby).


    Collisions broaden absorption lines, but do not change the peak frequencies that they occur at. If anything, they increase the frequency range that abosportion can occur at (i.e. – Lorenz aka collision broadening)

    One thing to keep in mind, and this is the key to the whole way that the CO2 influence on the greenhouse effect works, is that Water and CO2 rotational-vibrational bands do not overlap for the most part. Their absorption bands have an independent effect on the greenhouse effect. Water is basically constant while CO2 in not (growing due to pollution). In addition, H2O is primarily a tropospheric effect, as it freezes out when it gets to the stratosphere while CO2 does not. It only takes a small smidgen of CO2 increase to block entire IR transmission r3egions from the troposphere. This is what is happening.

  45. 195
    Garrett says:

    W, for people who wonder who I am, I am Dr. Garrett W. Van Cleef, PhD, Ohio State 1989. I worked under John Shaw (recently deceased, God bless him) and Crofton “Barney” Farmer of JPL 20 yeas ago. At this time, I work in pprivate industry but am again getting the itch to complete my work on atmospheric tides that I left 20 years ago (so much new data :)

  46. 196
    Tim McDermott says:

    Rod B says:
    20 December 2009 at 5:15 PM

    But there has to be some other way to get an independent credible assessment. I would suggest the scientists have to come up with some agreeable method because, maybe through no fault of your own, and like it or not, you all have a public relations tiger by the tail.

    Rod, It is the nature of scientists that they are, collectively, independent assessments of each other. Those who suggest that there is a conspiracy among all the scientists who are competent to perform an assessment are, IMO, delusional. The scientist who could convincingly demonstrates that AGW is not happening, or is not a serious threat to humanity, would be lionized. The reality is that scientists are motivated by the intellectual chase and by status. Debunking AGW would be the achievement of the century. Those who cry “conspiracy” seem to think that scientists are driven by money.
    Only fools go into science to make money. Except for Senior Executive Service folk, nobody at GISS can make $153,000 per year, because that is the top of the pay scale in New York City. Consider that a registered nurses with anesthetist certification can make $250,000 in Virginia. I don’t doubt that Gavin Schmidt could make between a million and ten million dollars a year as a quant on Wall Street. Science is not lucrative. Those who think there is a conspiracy need to come up with a realistic motive.

  47. 197
    Ray Ladbury says:

    Rod B. @191 That is an insightful comment. However I would raise a question on the following suggestion you raise:

    “But there has to be some other way to get an independent credible assessment. I would suggest the scientists have to come up with some agreeable method because, maybe through no fault of your own, and like it or not, you all have a public relations tiger by the tail.”

    To date, we have mountains of evidence, both literal and figurative, showing the climate is changing and that we are the ones doing it.

    This evidence and the methodologies of obtaining it have been assessed by the National Academy of Sciences in the US, and by National Academies all over the world. These committees included scientists whose reputations are above reproach and who work in fields outside climate science, but who possess enough knowledge to form an independent assessment. These assessments uniformly validate the results and methodologies that point toward the reality of climate change.

    The evidence and methods have been assessed by dozens of independent professional associations of physicists, chemists, meteorologists, even petroleum geologists. Not one organization dissented from the consensus.

    The results, and even the individual scientists who published them, have been investigated by hostile committees in the US House and Senate (which found bupkes to censure). The results have been scrutinized by legislative bodies, government and military bodies–even the Vatican. Not so much as a word of dissent–in fact most are urging immediate action.

    So, I’m wondering: Who is left? Who could assess the science and reach an independent validation that so-called skeptics would accept? To me, it looks as though most would not be persuaded regardless of any evidence produced or any amount of validation.

  48. 198
    Hank Roberts says:

    Rod B:
    > wiggles
    wiggles, defined:

    “Molecular spectroscopy involves the interaction of electromagnetic radiation with the molecules of the material …
    Many things in nature wiggle back and forth. We call a wiggle in time a vibration. We call a wiggle in time and space a wave….
    Molecular Vibrations
    One of the oldest forms of spectroscopy uses the infrared region of the electromagnetic spectrum. In order to understand IR spectroscopy, we must first consider the motion of atoms in molecules.”

    Atoms in a molecule do not maintain fixed positions with respect to each other, but actually vibrate back and forth about an average value of interatomic distance with a certain frequency.”

  49. 199
    Hank Roberts says:

    Rod, just to illustrate for any kid who comes along the process of checking what one thinks, I hope you don’t mind being the demonstrator.
    Demonstratee. Whatever.

    192 Rod B says: 20 December 2009 at 5:20 PM
    > … I thought molecules absorbed IR because they have a polar moment,
    > not because some wiggle better.

    It’s a poor sort of memory that only works backward. For everything else, we have search engines.

    Pick a molecule we know absorbs infrared. You can visualize some of them fairly easily. Methane is a greenhouse gas. Memory says it looked symmetrical, at least forty years ago when I formed that memory. YMMV.

    Can we check? Is it polar? And what do we mean by that?

    Finds us this among the first page of results:

    “… the C-H bonds in methane are polar. However, a molecule of methane is non-polar. Specifically, the dipole moment of methane is zero…. Think of the “center of charge”, whether positive or negative, in the same way that you think of the “center of mass”…. a molecule with a dipole moment of zero is like a perectly balanced see-saw.”

    Looking for pictures, I found this:

    Animations on this page illustrate the text description:

    “Vibrations fall into the two main categories of stretching and bending.
    Stretching: Change in inter-atomic distance along bond axis
    Bending: Change in angle between two bonds.
    There are four types of bend:
    * Rocking
    * Scissoring
    * Wagging
    * Twisting….”

    Of course you may find better explanations. And it’s always good to ask yourself, when you find you had somehow formed a mistaken certainty, where you got the idea that misled you — did you read it on a website somewhere, or did you come to the mistaken conclusion on your own?

  50. 200
    Doug Bostrom says:

    Tim McDermott says: 20 December 2009 at 8:23 PM

    “Those who think there is a conspiracy need to come up with a realistic motive.”

    Trouble is, for those inclined to buy into conspiracy theories, it’s totally plausible to believe in crypto-Marxist plots to create a world government bent on redistribution of wealth, under the guise of addressing global warming.

    “ClimateGate”* celebrants are just a few short steps along a continuum from survivalists holed up in cabins with thousands of rounds of ammo and tons of freeze-dried ice cream, eagerly waiting for the arrival of the Black Helicopters.

    (* ClimateGate. First, isn’t it time to retire the achingly tired and expired “Gate” thing, already? Second, what a reflection on the mentality of contrarians, that they imagine this rises to level of Richard Nixon and G. Gordon Liddy, or Ronald Reagan and his Iranian pals.)

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