As many people will have read there was a glitch in the surface temperature record reporting for October. For many Russian stations (and some others), September temperatures were apparently copied over into October, giving an erroneous positive anomaly. The error appears to have been made somewhere between the reporting by the National Weather Services and NOAA’s collation of the GHCN database. GISS, which produces one of the more visible analyses of this raw data, processed the input data as normal and ended up with an October anomaly that was too high. That analysis has now been pulled (in under 24 hours) while they await a correction of input data from NOAA (Update: now (partially) completed).
There were 90 stations for which October numbers equalled September numbers in the corrupted GHCN file for 2008 (out of 908). This compares with an average of about 16 stations each year in the last decade (some earlier years have bigger counts, but none as big as this month, and are much less as a percentage of stations). These other cases seem to be mostly legitimate tropical stations where there isn’t much of a seasonal cycle. That makes it a little tricky to automatically scan for this problem, but putting in a check for the total number or percentage is probably sensible going forward.
It’s clearly true that the more eyes there are looking, the faster errors get noticed and fixed. The cottage industry that has sprung up to examine the daily sea ice numbers or the monthly analyses of surface and satellite temperatures, has certainly increased the number of eyes and that is generally for the good. Whether it’s a discovery of an odd shift in the annual cycle in the UAH MSU-LT data, or this flub in the GHCN data, or the USHCN/GHCN merge issue last year, the extra attention has led to improvements in many products. Nothing of any consequence has changed in terms of our understanding of climate change, but a few more i’s have been dotted and t’s crossed.
But unlike in other fields of citizen-science (astronomy or phenology spring to mind), the motivation for the temperature observers is heavily weighted towards wanting to find something wrong. As we discussed last year, there is a strong yearning among some to want to wake up tomorrow and find that the globe hasn’t been warming, that the sea ice hasn’t melted, that the glaciers have not receded and that indeed, CO2 is not a greenhouse gas. Thus when mistakes occur (and with science being a human endeavour, they always will) the exuberance of the response can be breathtaking – and quite telling.
A few examples from the comments at Watt’s blog will suffice to give you a flavour of the conspiratorial thinking: “I believe they had two sets of data: One would be released if Republicans won, and another if Democrats won.”, “could this be a sneaky way to set up the BO presidency with an urgent need to regulate CO2?”, “There are a great many of us who will under no circumstance allow the oppression of government rule to pervade over our freedom—-PERIOD!!!!!!” (exclamation marks reduced enormously), “these people are blinded by their own bias”, “this sort of scientific fraud”, “Climate science on the warmer side has degenerated to competitive lying”, etc… (To be fair, there were people who made sensible comments as well).
The amount of simply made up stuff is also impressive – the GISS press release declaring the October the ‘warmest ever’? Imaginary (GISS only puts out press releases on the temperature analysis at the end of the year). The headlines trumpeting this result? Non-existent. One clearly sees the relief that finally the grand conspiracy has been rumbled, that the mainstream media will get it’s comeuppance, and that surely now, the powers that be will listen to those voices that had been crying in the wilderness.
Alas! none of this will come to pass. In this case, someone’s programming error will be fixed and nothing will change except for the reporting of a single month’s anomaly. No heads will roll, no congressional investigations will be launched, no politicians (with one possible exception) will take note. This will undoubtedly be disappointing to many, but they should comfort themselves with the thought that the chances of this error happening again has now been diminished. Which is good, right?
In contrast to this molehill, there is an excellent story about how the scientific community really deals with serious mismatches between theory, models and data. That piece concerns the ‘ocean cooling’ story that was all the rage a year or two ago. An initial analysis of a new data source (the Argo float network) had revealed a dramatic short term cooling of the oceans over only 3 years. The problem was that this didn’t match the sea level data, nor theoretical expectations. Nonetheless, the paper was published (somewhat undermining claims that the peer-review system is irretrievably biased) to great acclaim in sections of the blogosphere, and to more muted puzzlement elsewhere. With the community’s attention focused on this issue, it wasn’t however long before problems turned up in the Argo floats themselves, but also in some of the other measurement devices – particularly XBTs. It took a couple of years for these things to fully work themselves out, but the most recent analyses show far fewer of the artifacts that had plagued the ocean heat content analyses in the past. A classic example in fact, of science moving forward on the back of apparent mismatches. Unfortunately, the resolution ended up favoring the models over the initial data reports, and so the whole story is horribly disappointing to some.
Which brings me to my last point, the role of models. It is clear that many of the temperature watchers are doing so in order to show that the IPCC-class models are wrong in their projections. However, the direct approach of downloading those models, running them and looking for flaws is clearly either too onerous or too boring. Even downloading the output (from here or here) is eschewed in favour of firing off Freedom of Information Act requests for data already publicly available – very odd. For another example, despite a few comments about the lack of sufficient comments in the GISS ModelE code (a complaint I also often make), I am unaware of anyone actually independently finding any errors in the publicly available Feb 2004 version (and I know there are a few). Instead, the anti-model crowd focuses on the minor issues that crop up every now and again in real-time data processing hoping that, by proxy, they’ll find a problem with the models.
I say good luck to them. They’ll need it.
Phil, in equilibrium, you won’t have a temperature change, right? And technically, you are right, since photons are bosons, and so, not conserved. However, on average, in equilibrium, energy out=energy in, and neither temperature, nor any other intensive variables change. Note, I am not talking LTE, here, but true equilibrium
Gunter:”I understand that, but by close inspection, calculating myself, I realized that the bracketed function contains an additional 1/phi which should go to zero right?”
The excitation is also dominated by collisions (statement at bottom of pg 74), so b/B is also large, and compensates for A/a.
RodB 545, YOU are the one who brought up iron in a discussion about how radiation is retained by an atmosphere.
Not me.
So you’re now saying that that was a stupid question you asked Ray. Is that right? Or is your point 545 stupid instead. One or ‘tother is dumb.
t_p_hamilton #552,
you wrote:
“The excitation is also dominated by collisions (statement at bottom of pg 74), so b/B is also large, and compensates for A/a.”
Yes, but since phi or a/A cancels with 1/phi or A/a, shouldn’t he have pulled out b/B. Extraction of phi like that seems arbitray, one can do that from any function or constant. Therefore claiming afterwards:
“The quantity in brackets ((c*b12*A21)⁄(4*π*a21*B12)) must therefore be the Planckfunction Bv” looks also arbitrary.
Hank, well! I’ll be! Though I think “neutron star atmosphere” is a bit of an oxymoron. ;-)
Mark, I brought up iron in the context of accelerating charges causing radiation. The relation to atmosphere was only to imply that the former is strangely often ignored or forgotten when talking of the latter. My question was just a rhetorical construct to make the point, as everyone else seems to understand.
What was stupid about my 545? The part where I agreed with you? Or what??
554:
This seems to be basically
(a * b) / (A * B)
Now, as a/A goes to 0, the result will go to zero UNLESS B/b goes to zero too.
This is how photons get to light speed and have inertial mass according to Einstein’s Theory Of Special Relativity:
m(v) = Ym(0)
Where Y=(1-(v*v)/(c*c) and m(x) is the mass of the particle at velocity X.
So, as v tends to c, m(v) tends to 1/0 = infinity because Y tends to 1/0. BUT what if there is zero rest mass? m(v) then tends to 0/0.
So if m tends to zero quicker than Y tends to 1/0 then mass will increase for this morphing particle.
Likewise, if b/B tends to zero quicker than A/a tends to zero, the result can go UP.
Fairly simple A level (even O level) Physics.
Guenter:” 554.
“The excitation is also dominated by collisions (statement at bottom of pg 74), so b/B is also large, and compensates for A/a.”
Yes, but since phi or a/A cancels with 1/phi or A/a, shouldn’t he have pulled out b/B. Extraction of phi like that seems arbitray, one can do that from any function or constant.”
Not if the denominator is 1+phi, with phi large. Pulling out b/B would be pulling out 1/large number, not a large number, and would not cancel with the denominator.
t_p_hamilton #558,
“Not if the denominator is 1+phi, with phi large. Pulling out b/B would be pulling out 1/large number, not a large number, and would not cancel with the denominator.”
The small b is the excitation by collision, meaning b/B is large. If b dominates.
Mark #557,
You wrote:
“Likewise, if b/B tends to zero quicker than A/a tends to zero, the result can go UP”
I know that.
But look at the function: It says (b*A*a)/(a*B*A). The result is b/B.
So if b/B tends to zero quicker, the whole term is zero isn’t it?
John Houghton says its (infinity*b*A)/(a*B). The only justification might be if b/B goes also towards infinity, since A/a goes towards zero. But calling the remaining bracket the Planckfunction I think is arbitrary, if there is no other justification.
Rod, yes, iron atmospheres around neutron stars are rather thin:
“… Since a characteristic thickness of the NS atmosphere,
∼ 0.01 − 1 cm, is much smaller than the NS radius, and
characteristic densities are rather high, we consider the
plane-parallel atmospheres in local thermodynamic equi-
librium. Following a standard approach (e. g., Mihalas
1978), we proceed from the radiative transfer equation ….”
http://arxiv.org/pdf/astro-ph/9604072
RodB. Iron is a metal. Free elecrtrons don’t flow unless you throw the iron through a magnetic field.
So it still has nothing to do with what you presume to be forgotten.
It is also strange that the gargantuanly vast proportion of the troposphere is not ionised, so why would there be free electrons? All the electrons are in atoms and they aren’t free to move about.
Add to that the fact that most binding energies for electrons in our gaseous atmosphere are several eV and take them mostly out of the visible range, never mind infra-red and I fail to see why forgetting about free electrons (which don’t do absorbtion: the photon field is still impinging on the electron as it is being excited and “absorbs” energy hence causing a sympathetic reradiation in the same plane as the original photon) is an issue for you in our atmosphere.
You say you have been clear but please explain to me the information you think you are imparting because I don’t get it.
PS Rod in 556, where in 545 did you agree with me? All you did was repeat what I said to you. That isn’t agreeing.
[edit]
Mark says, “…All you did was repeat what I said to you. That isn’t agreeing.”
It’s not??!!? :-?
Geunter,
Jim here.
I’ll look at yours in a minute, and see if I have anything I could add.
Eli, if you’re out there. Thank you for your reference on the other page.
I think I looked at that one a little while back.
If I recall, it was very good work.
1. If memory serves, the intensities were weak, on the order of what I described earlier, certainly not on the scale of W/m^2.
2. I do not think they extended the path length looking for maximum signal.
3. I believe the authors have successive papers in which they use the same technique against clouds – a much longer path length, but still with weak signals not much changed in order of magnitude.
4. It is true that the author’s claim this refutes my point, I’m not so sure. Yes, they did find a result very close to the computed result. However, I would need to know more about the computed result.
My suspicion is that result uses tables for the A and E matrices of the gases of interest. Those tables are derived from a mix of empirical observation and computation, possibly guaranteeing a match even if the theory is incorrect. At this time, I do not accept the use of the matrices describing the continuum, as gases aren’t active in much of the range.
Best I can tell, this technique is a modified version of gray body calculations used to monitor chemical combustion. The continuum matters in that case – many states are accessible in combustion.
I bring this up, because there are an infinite number of ways to replicate spectra computationally, but unless the correct ones are chosen, extrapolating to other circumstances can quickly fail. Replicating the spectra observed successfully does not necessarily imply that introducing a change will correctly predict the changed spectra.
5. I strongly suspect that given long enough path lengths with the technique in the paper mentioned will lead to convergence at the same intensity as achieved with a hot source.
That is to say, when absorption occurs (from a hot source) it proceeds until the emission level of the material is reached (very non-Beer’s Law close to the emission level for obvious reasons). When emission occurs (cold source) the reverse occurs, again until you reach the emission maximum. These values should coincide, and are, I suspect, much less than the W/m^2 intensity range for most gases in the atmosphere. The planet does emit in the W/m^2 range.
You can see how I might think that the low intensity observed supports my thesis rather than the one proposed by the authors.
I know this has been hollered about many times before on these pages, but currently, I remain of the opinion that pretty much all of the absorption CO2 can do, it has done. I’ve seen the work arounds, but at the moment, I don’t accept them.
In any event, here’s another long one. I’m on a different thread now, but if you care to vote me off the island, I will leave peacefully. JCBMack appears to be a good contact, and it sounds like he’s willing to extend this for the years it may take to either bring me around or bring him around.
Geunter, I’ll take a look at yours. Be aware that I may find myself out of field very quickly. Most folks here think I’m already in way over my head – I’ve gotten pretty used to that in conversation round about.
Cheers.
I see I have to go to Google books to find more info, Thanks Ray. I wasn’t aware that was available. I believe I worked through the equations in Goody and Yung a while back, but will have to revisit that. If it takes me too long to get back to this, I’ll just write to JCBMack. Let me see if I can come up with a response today, however. Sure, my gut says “agree, with it, you like the conclusion”, but that wouldn’t be proper, and is often incorrect.
Cheers, Jim
Guenter:”“Not if the denominator is 1+phi, with phi large. Pulling out b/B would be pulling out 1/large number, not a large number, and would not cancel with the denominator.”
The small b is the excitation by collision, meaning b/B is large. If b dominates.”
And would not cancel with the denominator, hence useless for approximation. Using the old trick of multiplying and dividing by the same number (phi), and factoring it out, compensating by 1/phi in the second term IS useful.
Okay, Geunter, on the surface, it looks like your conclusion is pretty good (1/phi)*phi always equals 1. The way the terms are defined, phi could certainly be used within the brackets, and cancelled. I would prefer to get my hands on a complete copy of the book, since it looks like the LTE arguments are developed in previous chapters.
Having said that, it is not that hard to work with coefficients of spontaneous emission and stimulated emission, and discover that if you set the rates of absorption and emission equal to each other, then the rate of spontaneous emission exceeds the rate of stimulated emission by about a factor of 10 (at an energy of 700 cm-1, near 15 microns). This situation holds within an enclosure, and within an enclosure, the Planck function is generated.
Temperature is proportional to average kinetic energy. In an open system, when two items are at the same temperature, they need not have the same radiation field. This is easily verified by taking the spectra of items, or if you prefer, you can look up the optical properties of IR mirrors. Generally, it is good practice to choose a mirror that has a low emission in the range of interest. The same holds true for selection of windows and fibers.
There is a thermodynamic law of energy conservation, there is no thermodynamic law of radiation conservation. Absorption and emission from substances is characteristic of the substance both in frequency and intensity, and can be used as an IR fingerprint given an appropriate library of spectra. Any gas that is IR active could be given enough path length for “complete” absorption – down to the point where the signal stops changing – refer to my previous post. This does not imply that the gas will then emit on the same scale as it absorbs – in fact quite the opposite, a net absorption is observed precisely because the absorption process dominates the emission process.
Interestingly, looking at the Houghton reference you see the statement “..we have neglected stimulated emission…as spontaneous emission dominates”. This would be true within a cavity, as I’ve mentioned above.
However, this system is open, allowing exchange of both energy and matter. In a similar situation, Atkins contends (Physical Chemistry, 6th edition, p. 461) “Spontaneous emission can be largely ignored at the relatively low frequencies of rotational and vibrational transitions, and the intensities of these transitions can be discussed in terms of stimulated emission and absorption.” Atkins leaves spontaneous emission out of his equation for net rate of absorption in the IR range.
Spectroscopists tend to ignore spontaneous emission until you get into the visible range, when fluorescence measurements become practical. In fact, if you follow the development of fluorescence in Atkins, you will see that following the vertical transition, the excited state falls to the ground state by radiationless decay (I’m speaking of the vibrational ground state of the excited electronic state.) The energy difference between the vibrational states of the excited state is on the order of IR radiation, but is not mediated by a photon. Spontaneous IR emission in this range is generally ignored. However, for development of the LTE radiative transfer theory, the spontaneous emission must be large, as Houghton claims. If the spontaneous emission is negligible, then the theory does not provide significant impact. Stimulated emission is of course always in the same direction as the stimulating photon – which is critical for LASER function. If the earth provides the radiation, then only spontaneous emission can return to earth, and spontaneous emission is simply negligible at atmospheric pressures – in which collisional relaxation dominates so markedly, as is evidenced by measurements such as the one Eli provided. The scale of the Y-axis is there, and it isn’t even close to the scale needed for representation of planetary emission.
That should do it for now. Yes, I avoided the original question – providing a good answer for that may well require acquiring the book, and spending more time with a pencil and paper. I apologize for not having it on the tip of my tongue. However, I can point out that all of this hinges on whether or not you accept the claim of a Planck source function from the atmosphere. I think it is clear from published spectra that Planck intensities are not even remotely achieved from the atmosphere, but are approximated from the surface. This fits the current models I have floating in my brain. A measurement that shows Planck level intensities coming from the atmosphere blows my theory out of the water.
Goody claims that most of the radiation observed comes from the atmosphere (and hence would be in the W/m^2 range), but most of the radiation observed from space is precisely in those bands in which atmospheric gases are inactive, so this appears incorrect. Furthermore, in those regions observed, the surface of the planet can be imaged in the IR. Were that radiation continually absorbed and isotropically emitted on its way out, information pertaining to the surface would be completely scrambled.
Cheers,
Jim
Jim, I see you are using Atkins, my favorite author, and not only that, but correctly, I am busy, but I could not resist reading your latest posts and posting a quick response. You are quoting and interpreting the textbook correctly, which is rare I might add, even by scientists outside P chem. We have much to discuss, but you are on the right track, though I do want to add that CO2 can absorb an enormous amount of radiation before emitting and the heat content is not emitted immediately either. I will get back to you after grading papers and so forth, your comments are interesting and I want to get into details soon.
Yes this may take some time Jim, but I have been bored anyways…
Since I haven’t been voted off the island yet (probably because no one has yet read anything I’ve written), I may as well fire off another one. (I’m getting in as much as I can while I have time, and before someone puts a stop to it.)
If you’ve gotten this far, you certainly noticed that I rather bluntly stated I’d leave out the continuum matrices for computation of a gas phase spectrum near STP.
If you looked at the literature emission spectra, you certainly noticed that there is in fact a continuum component. Obviously I’m out of line with the data.
In my feverish brain, it occurs that the atmosphere is heterogeneous. If you look for particle size distribution, you can find a report that (if memory serves) states that particulates in the atmosphere are coarser near the top of the atmosphere, finer in the middle, and coarser again near the ground. I do not recall if the report discussed particle concentration or (more importantly) surface area.
It is not unlikely that these solid particles dispersed throughout the atmosphere emit with a coefficient near to unity. If so, this could complicate the radiation problem, as radiative energy transfer between particles is active, and will roughly follow the LTE model that has been proposed for gases, if I am correct in the hypothesis that a fair fraction of these particles have emission coefficients near unity.
However, it appears based on emission data gathered in the atmosphere that the effect of these particles is weak, since the continuum background is measured on a scale of microwatts/cm^2.
That may be my last two cents for a little while.
Cheers,
Jim
Jim,
The Houghton book is easily seen via
http://books.google.com/books?id=MXnlpqI0MIIC&pg=PA72&lpg=PP1&dq=houghton+physics+of+atmospheres&output=html and browsing forward. What Guenter is asking about is a section that does the LTE approximation. Houghton then goes on to discuss when this approximation breaks down. It is in fact dealing with the issues you bring up.
About neglecting spontaneous emission, the reason physical chemists do this (texts are mainly looking at individual molecules in the gas phase) is that the ratio of the Einstein coefficeints for spontaneous and stimulated emission depends on frequency cubed, and hence is rapidly less important at low frequency.
Re #551
Ray Ladbury Says:
5 December 2008 at 11:12 AM
Phil, in equilibrium, you won’t have a temperature change, right? And technically, you are right, since photons are bosons, and so, not conserved. However, on average, in equilibrium, energy out=energy in, and neither temperature, nor any other intensive variables change. Note, I am not talking LTE, here, but true equilibrium
Sure but I see nothing in that which requires photons in=photons out.
Jim,
A = U-TS or G = H-TS Inn GTE (global thermodynamic equilibrium intensive parameters like temperature (average kinetic energy, or averaging of molecular collisions and kinetic motion) controlling heat exchange, are homogenous throughout the whole system, whereas LTE (local thermodynamic equilibrium) dictates that the changes are so slow and gradual though they are changing and varying in space and time, they may be considered to be (the intensive parameters) LTE at a given point. Keep in mind that temperature is proportional to its internal energy of an equilibrated area. Also, local equilibrium applies to massive particles, in a radiating gas the photons being emitted and absorbed by the gas do not have to be in equilibrium with each other or the massive particles of the gas for LTE to be so.(source one of your confusion about photons)
LTE can exist in a glass of water with an ice cube melting where at any point int he glass a temperature can be read, however, it is colder near the ice cube than farther away from it, so if the energies near a given point are observed they will be distributed according to Maxwell- Boltzman distribution for a certain temperature, and the same goes for another given point. Without exchanges between the system and the outside, LTE will not be a stable state.
Now, 1/2 RHO V squared gives the air density at any given altitude and the temperature changes will be affected as we go up,by about 2 degrees C (forget the increments of height increase, anyone?) and the density changes along with temperature changes will pose affects on the ghg’s kinetic energy, and heat transfer and overall net effect, until of course the altitude is too high for such effects,, so heat, again is a function of temperature, that average kinetic energy.
Also keep in mind that closed systems are really ideal oversimplifications so individual aspects of the universe may be studied, as the solar system, the earth, a state, a city, a town, this house, and a glass of water are all open systems, but we must start somewhere and we cannot take on the universe as a whole. The human body is an open system and it goes through exchanges with the surroundings and each performs work on the other, but there is an approximated maintained thermal equilibrium in the human body, and if it were not so, we would all die from hypothermia or hyperthermia. Yet if the body were in equilibrium (all the cells that is) we would all be dead, and non equilibrium models do a great job explaining ATP ases, phosphorylation, and dephosphorylation signal transduction, ion exchange and the affects of concentration gradients.
I should also not that there are non-LTE effects on adn from CO2 as well, (for another post) CO2 has a complex absorption spectrum with isolated peaks of around s.6- 4 microns and a complete block out of infared above 13 microns. Water vapor is more complex with many broad peaks of infared between o.8 and 10 microns. So CO2 is an excellent absorber of IFR. Running out of time for now, keep in mind NLTE does not mean that there is no globale thermodynamic equilibrium.
Jim also read: Non-LTE Radiative Transfer in the Atmosphere By Manuel
López-Puertas, F. W. Taylor on Google Books. p. 14 is especially helpful and I will be doing work out of my analytical chemistry textbook as well, my other references will be posted as well next time. (wife is being patient with me and papers are graded) Even in the same molecule one energy state within a molecule to be in LTE and another in the same molecule not to be. V2 and V3 (modes of vibration) within CO2 are in LTE at low altitudes, but at 40 km, V3 is not and at 100 km neither is. Much if this book is available for your reading so enjoy!
On earth, lower pressures more non LTE conditions (a function of altitude)
Phil’s right, Ray. Though this may be irrelevant. Energy in = energy out. However I don’t see what that has to do with your comment in 521.
Further to 572, strange isn’t it how the “skeptic” keeps saying that “the uncertainties are being forgotten” when if they actually read up about it, they’d find the admission of the uncertainties and inaccuracies.
I wonder whether it’s so they seem to be learned in the field.
Jim, #571. Could you explain what would make the higher particulates bigger than the lower particulates? Force required for uplift goes up with radius cubed. Force available by uplift goes up with radius squared.
re 564. No. If you’d said “OK, so …” rather than “so…” because the latter without the affirmation of acceptance can mean critical disbelief.
Re 561:
You state in 554:
“((c*b12*A21)⁄(4*π*a21*B12))”
Then you state in 561:
“It says (b*A*a)/(a*B*A).”
Where did you pull the extra a from? And why wouldn’t it cancel out the a in the numerator along with the two A’s above and below the division mark, where you’ve added a new A below the line?
take the numbers off because they are redundant from your statement in 554 you have
(c/4pi) which we aren’t going to vary because you haven’t talked about them, so that’s a constant.
then in the numerator:
b*A
and in the denominator
a*B
and you want to change A/a until it goes to zero and ask why it doesn’t.
Because if B/b goes to zero, we have 0/0 which is undefined.
Your 561 reduces to
b/B
Which doesn’t change if you change A/a because it no longer exists.
Mark,
1. Neutron stars do have atmospheres. They’re very shallow and don’t contribute much to the star’s radiation, though.
2. Photons have no mass.
t_p_Hamilton #567,
Thanks for your responses and your patience.
You wrote:
“And would not cancel with the denominator, hence useless for approximation. Using the old trick of multiplying and dividing by the same number (phi), and factoring it out, compensating by 1/phi in the second term IS useful.”
I agree this old trick of factoring something out is useful. I only think the factor 1/phi need to be also consolidated to zero as phi approaches infinity.
Let me therefore explain my difficulties from another angle.
Where I am struggling is just this:
The function Houghton shows is of the type: (b*A*a)/(a*B*A)).
The result is b/B. It is certainly also correct to factor out phi = a/A from the brackets and get (b/B*phi/phi). In turn also ((b/B*1/phi)*phi) or ((b*A/B*a)*phi). No problems so far.
However, doing the move towards infinity now for phi leaves behind a factor in the brackets (b/B*1/phi) or (b/B*A/a) that goes to zero. Note, A/a is 1/phi.
So I concluded the brackets must go to zero, if phi goes to infinity.
However, Houghton concludes that the bracket (b/B*A/a) times another function (c/4π), is the Planck function.
Of course in the LTE approximation, the result for the source function should be the Planck function. I wanted to know what argument I missed, maybe an integration or something that he didn’t mention.
I just wanted to know how this gap in the calculation is filled.
I didn’t find anything in the links Ray provided, kindly.
Best regards
Guenter
Mark #580,
Sorry for the confusion.
The equation is from John T. Houghton, The Physics of the Atmosphere 3rd edition.
My first post with the full equation is #540:
Js=(Iv+((c*b12*A21)⁄(4*π*a21*B12)*a21/A21))/(1+a21/A21)
t_p_hamilton and I were skiping indices and trade shorter versions as the discussion progressed.
Best regards
Guenter
Jim writes:
Then why is Venus so hot?
Mark,
It’s been a litte while since I read it. I don’t recall if an explanation was given, but supposed it may be due to uplift of particles for the lower altitude, and falling particles for the very high altitude.
I didn’t spend much time with this, just read the one report. At the time I was trying to get an idea of just how accurate the representation is that only radiative energy crosses the line. ie. The need for radiative balance.
I really did start at the beginning, and I’m questioning every assumption I see (but not the ones I don’t see yet).
I concluded that radiation is not the only means by which energy (and mass) crosses the boundary, but it is clearly the most important, and it is likely a fair approximation to neglect other transfer mechanisms.
After all, a simple radiative calculation does come pretty close. Including mass transfer effects across the border might not even come into play by any current available measurements, although I can’t really back that up just yet. I’ve left this particular line behind in light of my more recent obsessions.
Now I have a bunch of stuff from JCBMack to work through. That will take time, and might help me with my current problem – I’m working on something that might end up revising some of the Kirchoff’s Law assumptions, but I’m really not ready to share that yet, (as I’m probably full of it) and verification probably requires a fairly simple experiment, but still with equipment not available to me. I’m probably going to write that one and just leave it on my computer, bugging me until I do something else and forget it.
Cheers,
Jim
Barton,
I’m also looking at Venus peripherally.
One of the reasons why it so hot may well be because the temperature of Venus sits just above the primary stretching fundamental of CO2, which is a massive absorber. Note that the temperature of earth sits just above the bending mode of CO2, another massive absorber.
To complete the picture, I need to look for the modes of H2SO4, and see if they relate in position to the stretching mode in the same way that H2O relates in position to the bending mode.
In short, although both planets are heated by having CO2 in their atmospheres, their peak temperatures are pumping different bands. Both settle at a temperature higher than the respective band in play. To use much of the stretching mode on Earth, you’d have to bump up the temperature significantly to bridge the gap.
Given the spectra from space, a shift to higher temp on earth will move a greater fraction of its spectrum into the IR window, resisting the T increase. A shift to lower T shifts the peak closer to the active IR range and a larger fraction of radiation is absorbed.
This means the T is radiatively balanced by positions of active and inactive spectral ranges. This is rather what I would expect in a system that has been around for a long time – that it has found a well somewhere on the surface, I just don’t have a feeling for how steep or high the sides are yet.
Cheers,
Jim
Barton,
One more quick note, maybe you’ll do this before I get to it – since I’ve been intending to for a little while.
Set up an Excel spreadsheet for BB calculations, and calculate for 255 K.
Remove from that all of the lines for water and CO2 – assume full absorption, and a collisional line width of about 0.04 cm-1 for CO2, you can calculate a width for water too, I haven’t done that yet.
Add that energy back in and recalculate the T and a new Planck function. Iterate this process until the T stabilizes. I’m guessing it’s going to end pretty much pegged where it is now.
Do the same for Venus using H2SO4 – you can see why I haven’t done this yet, it’s going to take up a lot of lines on the spreadsheet.
Don’t worry about intensities, just locate positions – I’m hoping I can find positions for all these bands – and use a natural linewidth and the Planck function at T to figure your absorption.
My guess (one of you all will holler if I’m way off) is that both planets will stabilize to their respective temperatures – obviously you’re always normalizing relative to sunlight and position from the sun.
Cheers,
Jim
Barton,
Sorry, I said natural line width. Compute the collisional linewidth and use that. It should be the relevant value.
Cheers,
Jim
Jim,
great read on the subject of spectral analysis:
http://www.pollutionissues.com/Re-Sy/Science.html
This is superb!!!: http://www.warwickhughes.com/papers/barrett_ee05.pdf
A supplemental point: http://cdiac.ornl.gov/pns/current_ghg.html
More Hughton: http://cdiac.ornl.gov/trends/landuse/houghton
/houghton.html
main page: http://cdiac.ornl.gov/pns/faq.html
Jim,
following is excerpts, data, and illustrations from my “Fundamentals of Analytical Chemistry, Skoog, West, Holler, and Crouch. (chapter 24 pp. 710-741)
Interesting types of interactions in spectroscopy involve transitions between different energy levels of chemical species. Other forms of interactions like: reflection, refraction, elastic scattering, interference, and diffraction most often are related to the bulk properties of materials rather than to energy levels of specific molecules and atoms. Here energy level transitions get a more thorough treatment: The electromagnetic spectrum covers an enormous range of energies, or frequencies, and of course resultant wave lengths. The frequencies may vary from greater than 10^19 Hz (gamma rays) to 10^3 Hz (radio waves) An X ray photon (v= 3 times 10^18 Hz,) Lambda = 10^-10m) is approximately 10,000 times as energetic as a photon emitted by an ordinary light bulb (nu= 3 times 10^14 Hz, lambda = 10^-6m) and 10^15 times as energetic as radio-frequency photon (you get the idea, not all photon emissions are created equal energetically)
Here are some examples of spectroscopic methods in brief (at first) and the effects that may occur in quantum change: Nuclear Magnetic Resonance (NMR) Electron Spin Resonance (ESR) change of spin,
microwave: change of orientation, infared: change of configuration, visible and Ultraviolet, and X ray (UV) change in electron distribution (important)and gamma ray (y-ray) change in nuclear configuration.
Spectroscopists use the interatcions of radiation and matter to obtain information about a sample. The sensitivity and coupling of a wide variety of two and even three different sets of equipment gives us quite accurate data supporting empirical observations, and artifacts are carefully accounted for.When I have more time, I will walk you through the various types and coupling methods as you made some error regarding sensitivity what has actually been empirically measured. Till then, Jim, happy reading.
Oh, and not forget Beer’s law and exceptions to, and super critical fluid analysis of and in CO2.
Phil, WRT photons, It is true, photons are not conserved. However, if you have a different spectrum of photons from a blackbody, then it is not in equilibrium with the matter, so, waving our hands a lot and mumbling about the law of large numbers… I agree in principle with what you say. However, I’m trying not to complicate things too much.
Actually, there are corrections for Kirchoff’s assumptions under certain conditions, but we will discuss that at a later date, Jim. So many laws: Thermodynamics, (four)Henry’s, Fick’s, Boyle’s, Charles and so forth and each has some relevance to aspects of this discussion, some directly, some indirectly and non-linear, and let us not forget my personal favorite, quantum mechanical tunneling, but one step at a time… as I said this conversation will take quite a while, and yes U will post some of my own calculations, but I do have time constraints and I must use some prudence as I am also working on a paper which will be submitted for review somewhere down the line.
jcbmack Says:
6 December 2008 at 1:41 PM
…
This is superb!!!: http://www.warwickhughes.com/paper/barrett_ee05.pdf
—————
That link at warwickhughes opens up a copy of this:
ENERGY & ENVIRONMENT VOLUME 16 No. 6 2005
Greenhouse molecules, their spectra and function in the atmosphere
by Jack Barrett
That paper has been cited only once, in
Climate stability: an inconvenient proof
Author(s): D. Bellamy | J. Barrett
doi: 10.1680/cien.2007.160.2.66
That’s published in Civil Engineering; Bellamy and Barrett there write
“… the widely prophesied doubling of atmospheric carbon dioxide … will enhance the so-called ‘greenhouse effect’ but will amount to less than 1°C of global warming.” Check for citations thereof.
Recommendation: cite the original, rather than pointing to some blog copy of a single paper out of context, to make it easier for people to look for subsequent citations, corrections, and discussion if any.
The simple diagrams and explanation in the first paper may seem “Superb” — they’re not original research. I’d recommend looking further for sources to recommend on the basics.
In physical chemistry we begin with many assumptions.We also trust that an observed phenomena is due to the laws we learned and those five postulates of quantum mechanics. We can actually detect and understand very small peaks, narrow bands and the equipment is very sensitive to minor fluxuations and the signal to noise analysis is quite sophisticated: Look at this way, analytical instruments, stereos, cd players, and all sorts of electronic devices rely upon a standard of signal to noise ratio (S/N) or the ratio of the average value of output signal to its standard deviation. The spectrophotemeter, the MS equipment and so forth have been carefully calibrated and S/N ratio greatly enhanced: for more computerized instruments, methods like, analog filtering, lock- in apmplification, boxcar averaging, smoothing and fourier transformation among other methods are employed.
We also have photon detectors and Thermal Detectors in absorption spectroscopy… photon: phototubes, photomultiplier tubes, silicon tubes photoconductive tubes. thermal detectors: thermocouples, bolometers, pneumatic cells, pyroelectric cells and quite a few other subtypes. The ones just mentioned are transducers, one responds to photons, the other to heat.
IR may be detected by measuring the temperature rise of a blackened material located in a path of the beam or by measuring the increase in electrical conductivity of a photoconducting material where it absorbs IR radiation.
Chemists really explain mesophases in LCD screens and phase changes and transition phases as well as transition states and dipole moments in greenhouse gases. It is in the chemical physics, physical chemistry or chemical thermodynamics we begin to see these phenomenon unfold. as always non LTE is well studied and established:
ttp://www.oberheide-online.net/pages/pubs/pdf/PhysAtm6_01Kostsov2LO.pdf
Good read: Global Climate and Ecosystem Change By Gordon James MacDonald, Luigi Sertorio, North Atlantic.
Potential alternative fuel sources (off topic I know)
http://www.fespb2008.org/abstracts.pdf
Hank the reference is superb and the other references I posted with it supplement well and I did read what I cited, think it through Hank.
jc, you are pointing to a copy on a blog, not giving a cite. If you simply follow standard practice, you’ll make it easier for people to check rather than asking readers to consider you authoritative per se.
Barrett writes, for example
“… It would be expected that more CO2 would have a greater effect
on atmospheric warming at higher altitudes, but this seems not to be occurring in spite of the predictions of most GCMs…..”
Make sense to you? Where do you think he gets that?
Did you look at his references?
Good citation helps people to check this stuff on their own, and it’s excellent practice to get into if you hope to publish yourself.
Jim says, “One of the reasons why it so hot may well be because the temperature of Venus sits just above the primary stretching fundamental of CO2, which is a massive absorber. Note that the temperature of earth sits just above the bending mode of CO2, another massive absorber.”
OK, Jim, aren’t you just saying Venus is hot because it’s hot? Keep in mind, that molecular thermal energies are a distribution, not a delta function. Also, Venus is 108 million km from the Sun, so it only gets about 1.9 x as much sunlight as Earth–so the radiative temperature based on sunlight should only be less than 300 K. Now add in the fact that Venus has much higher albedo than Earth. In effect, you are relying on the greenhouse effect to explain the planet’s temperature. It appears that you feel that the greenhouse effect is saturated for Earth, but this was disproved in the ’40s.
jcbmack Ref 6 Dec 4:04 pm
Hank’s point is well taken. 6 Dec. 3:39 pm
Your reference appears to be a reasonable summary of the IR absorption properties of green house gases but hardly three exclamation points worth of superb.
The concluding paragraph of your reference seems a bit agenda driven with much emphasis on GCM uncertaintiy unrelated to much of anything in the main body of the article. Do you suppose they had to add this paragraph to get the article in E & E?
You are a prolific poster. Your patience in engaging Jim is remarkable. Your posts would contribute more with a little proofing and paragraphing. If a single sentence takes more than three lines, you might want to revise it. Sentences should have a subject, verb, object, typically in that order. Confine each post to a single topic–preferably on topic.
Paul
Do not waste so much energy Paul and Hank. My sentences are just fine, and the reference I gave is in regards to the subject matter Jim, myself and others are discussing. I will not confine a post to just one topic, this is a waste of time in such a subject matter that involves so many different perspectives and requires explanations that perhaps Jim or others miss.
The reference is superb because it leads to several questions, some regarding the limitations of the research itself, several mentioned within, myself, being a chemist, I must find literature and journals which provide a foundation for further inquiry… taylor series gets thrown around here, but some of the posters here do not even know how to use cramer’s rule using matrices which is very valuable in both physics and chemistry.
There are more thorough and peer reviewed journal citations and textbooks and other publications which I also included for further analysis; as someone who teaches this professionally I stand behind the brief reference as superb!!! because it makes one ask several questions and find more data regarding this area of research. The other references are citations and when read in conjunction with the ‘blog’ addition it all becomes quite clear, and no, we must not a=only speak about high end predictions or modeling, at any rate, enough about that, Jim, myself and others are discussing many concepts, equations and real world conditions in atmospheric chemistry and physics.