Inspired by a WUWT comment from Bill Illis in the Maybe they’ve found Trenberth’s missing heat thread, I’ve elevated this to full post status and provided the relevant graphics from the links Bill provided. From a National Science Foundation article on April 15th, 2010:
“The heat will come back to haunt us sooner or later,” says NCAR scientist Kevin Trenberth, the lead author. “The reprieve we’ve had from warming temperatures in the last few years will not continue. It is critical to track the build-up of energy in our climate system so we can understand what is happening and predict our future climate.”
===============================
Bill Illis writes:
Trenberth is looking for about 0.8 watts/m2 of the projected increase in energy held in the Earth system that is not going into heating the surface.
Either this energy is not being held in the Earth system (and is just escaping to space and hence climate theory is not correct) or it is hiding and the most likely place for that would be the deep oceans (or continental ice sheets warming up and melting that we have not observed).
This paper measured/extrapolated the potential heat content going into the nearly the entire global ocean below 2000 metres [It doesn’t appear they measured the Arctic bottom water but the north Atlantic does not appear to have warmed so it is likely no extra heat is going into the Arctic bottom water].
So, Table 1 in the paper shows 0.068 watts/m2 is going into the oceans below 2000 metres. Far less than the 0.8 watts/m2 Trenberth is looking for.
http://www.pmel.noaa.gov/people/gjohnson/Recent_AABW_Warming_v3.pdf
We also know there is no accumulation in the last 7 years in the 0-700 metre ocean – von Schuckmann 2009 found 0.77 Watts/m2 going into the 0-2000 metre ocean (although no one seems to believe these estimates since almost all of the warming they measured was in the 0-300 metre area which is contradicted by the Argo floats).
Trenberth Missing Heat – 0.8 Watts/m2
Going into 0-700 Metre ocean – 0.0 W/m2
Going into 0-2000 Metre ocean – ? (but could be as high as 0.77 W/m2 but this contradicts Argo)
Going into the 2000+ Metre Ocean – 0.068 W/m2
Going into the 2000+ Metre Ocean from the Arctic – ? (but looks to be very low)
===============================================
It is unlikely that the ARGO measurements are wrong, and thus it can’t be found in the oceans, so where is it? Balancing budgets is never easy; there’s always a missing penny somewhere. Most often, that missing penny is due to human error. – Anthony
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
“”” Julian Braggins says:
September 29, 2010 at 1:27 am
George E. Smith says:
September 28, 2010 at 11:31 am , a long and comprehensive explanation to my query, for which I thank you very much, and feel honoured by the time you must have spent on it.
I found the following paper today that may interest you, on the effects of CO2 in the atmosphere that concludes that further CO2 will not heat it and may cool it.
http://mc-computing.com/qs/Global_Warming/EPA_Comments/TheGreenhouseEffect.doc
Thank you again, Julian “””
Well if it was any help to you then it was worth writing.
As for your most recent discovery cited above; I would suggest doing some checking of the author’s sources.
Back in the early 1900s when Physicists were discussing and developing the theory of thermal radiation and the Planck radiation and Stefan-Boltzmann laws; I don’t recall anybody excluding gases whether diatomic or not; from emission of thermal radiation when they happen to be at aTemperature above zero Kelvins.
The sun after all seems to have no problem at all emitting thermal radiation; that is a continuum spectrum that is characterized pretty much completely by its Temperature.
It would be an absolutely trivial laboratory experiment to make an artificial atmosphere sample containing nothing but N2, O2, and Ar, in fact one could probably make sure it was all 14N, and 16O so it had isotopic purity as well; although I wouldn’t expect it to make much difference to the result. I would arrange the gas in a closed circuit tube through which the gas could be made to flow by an internal “fan”‘ and the tube could be surrounded by a substantial cooling water jacket to keep it at low temperature; while at some remote location in the tube; the gas could be headed by conduction from some metallic conduit in the end of the tube.
So the air would be heated by conduction up to quite high temperatures; limited by the melting point of the (probably quartz) tube; but the glass itself would be kept cool by the water jacket; and one could look through an inspection port in the side of the cooling jacket; and observe any radiation coming from the gas.
I’ll bet that if you do this; that you will be able to observe a normal continuum thermal radiation spectrum coming from that gas mixture; or you could use any single component say nitrogen alone or e3ven argon; and you will get exactly the same spectrum at a given Temperature.
The supposed mechanism for the emission of a thermal spectrum is simply the acceleration of electrons associated with the thermal mechanical motion of the molecules as they collide with each other. It’s a prediction of classical Physics I believe; and in fact was one of the stumbling blocks of the early forms of the Bohr atom explanation for spectral lines. He originally proposed that the frequencies of the spectral lines of atoms, were simply the frequencies of the orbital roations of the elctrons around the nucleus. In those days the atom was simply a small planetary ssytem.
Well it was a good idea; but unfortunately if those electrons were whizzing around the Nucleus in those planetary orbits, at Optical frequencies of hundreds of THz, they would according to classical Physics be in a State of Constant acceleration; since velocity is a Vector quantity; and a change in direction (going aorund in a circle) is an acceleration; so classical physics predicted a continuous radiation of energy. Well that continuous radiation of an accelerated electric charge is quite real, and is the whole reason for the two mile long Stanford Linear accelerator.
So Bohr eventually changed his thinking and proposed that the electrons wouldn’t radiate so long as they stayed in their assigned orbits (all of which were supposed to be different. And he suggested that they would only radiate (spectral lines) if they changed from one orbit to another; and the radiated energy would correspond to the difference in energies of the two orbits 9starting and final.
So the whole theory of Atomic spectra and the Bohr atom evolved from that idea; but it didn’t erase the experimental observation that an accelerated electric charge does emit radiation.
Now Anna knows a hell of a lot more about this than I do; and I haven’t dealt with it in 50 years or so; but so far as I know any gas that is heated above zero Kelvins stillemits thermal continuum radiation just like any liquid or solid material does. It certainly does on the sun.
Teh problem is that at ordinary atmospheric Temperatures; that radiation has a spectrum that peaks in the 10 micron range; and no human senses respond in any way to radiation at those wavelenghts; so we do not sense that as “heat” or anything else.
So hold up a brick out of the yard near your face and feel the “thermal radiation coming off it. You may want to cool it down to room temperature before you do it.
Well that brick is still emitting something in the 400 Watts/m^2 of LWIR thermal radaition; and that is what is captured by GHGs; and also is about what the atmosphere emits.
So I would take that paper you gave here with a grain of salt.
I know all the gas filled incandescent lamps certainly emit a lot of thermal radiation as well as visible light from the gas itself. The tungsten filament is just far too small an area to be a very effective light source. Well it’s a great source of light but the luminance is far too high to be comfortable to human eyes; so you need to increase the radiating volume, and lowere the Luminance of the source to comfortable levels. When you do that with scattering diffusion; you lose a lot of light to back scattering.
LEDs have a similar problem; the surface Luminance (Lumens per square meter per steradian) is just too damn high for comfort; in fact you have to comply with some laser safety radiation standards for the newest generations of high efficiency LEDs.
Gases; including N2 and O2 and even Ar radiate continuum thermal energy spectra just fine.
George E. Smith says: (September 29, 2010 at 10:58 am)
“Gases; including N2 and O2 and even Ar radiate continuum thermal energy spectra just fine.”
I believe this is an example of a statement that cannot be said to be false, only almost false. That is because these gases are not *perfectly* transparent. Just as these gases, in a non-ionized state, actually do absorb a small amount of radiation, (mediated by molecular collision events, I believe) it is my understanding that they also emit radiation in the same miniscule proportion.
I think it is also possible to say that a statement like “N2 and O2 cannot lose heat by radiation to outer space” is not true, it is only almost true or ‘practically’ true.
I believe the general rule is that only black-bodies can emit true black-body radiation.
RE: Julian Braggins: (September 29, 2010 at 1:27 am)
I found the article you referenced “How Greenhouse Gases Work” by Robert Clemenzi, (2009) rather interesting especially as he claims that the basic “greenhouse theory” was developed in the 1890’s before there was any knowledge of the structure of the upper atmosphere. It had been my previous impression that CO2 played a large role in expelling heat from the tropopause, but Clemenzi claims that CO2 is still saturated at that level and tropopause cooling is primarily mediated by H2O. I assume this is because water tends to condense out of the cold, thin air above the tropopause.
He also claims that that CO2 is responsible for the mesopause, at an altitude of about 90 km where this gas finally becomes thin enough to radiate to outer space. This is the first time I have seen this claim advanced. I believe he is saying that H2O is the primary coolant in the lower atmosphere and also the dominant heat-trapping agent near the surface and in the rarified air of the upper stratosphere and the mesosphere above, CO2 acts primarily a coolant.
To Spector:
The sun is a ball of hydrogen. Why does it emit blackbody radiation?
RE: pochas: (September 30, 2010 at 2:54 pm)
“The sun is a ball of hydrogen. Why does it emit blackbody radiation?”
I believe, in the case of the sun, we are talking about *ionized* hydrogen. That means the gas is so hot that molecular bonds cannot hold and electrons are being dislodged. Ionized gases are not transparent. You cannot see through the sun. I think it does qualify as a black body in that case. You can see through the Earth’s atmosphere, however.
In the case of a flame, I believe it is only the ionized area of active oxidation that glows and as soon as this stops, there is a rapid transition to transparency. Otherwise I believe the flame would look more like an expanding lollypop instead of a pencil point.
Well of course there are no black bodies, therefore there is no black body radiation; it is a purely theoretical construct. But we can make completely artificial physical objetcs which when heated emit an amount of EM radiation, that is Spectrally distributed almost exactly as prescribed both in amount and spectral distribution as the Planck and Stefan Boltzmann laws call for for the ideal black body. Further more; these artificial “near black bodies” emit a radiation that depends almost entirely on only the Temperature; and is independent of the materials of the object except to the degree that it is the limitations of the properties of those materials that lead to the non-ideal BB nature of the radiation. In that sense it is “Thermal Radiation”, in that the properties of the radiation are largely dependent on nothing but the Temperature; so it is not characterized by any “line spectra” or the like that are quite dependent on the atomic or molecular structure of the materials.
To the extent that the total emittance of such practical bodies is less than sigma.T^4 as specified for Black Bodies, we refer to them as grey bodies; and assign a “Total Emissivity” to them that is less than unity, representing the extent to which they fall short of being black.
Also some examples depending on construction materials or surfaces; may be spectrally biassed, in that some parts of the expected Planck Formula spectrum are missing. We refer to these as either blue or pink bodies in the event that the missing radiation is at one or other end of the spectrum, although more complex case that have “holes” in the middle do occur.
In any case, we can make very good approximations to ideal black bodies for use in the laboratory. In the case of the deep oceans where between 2 and 3% of the total solar energy that falls on the surface is reflected according to the Fresnel reflectance formulae; the remaining 97 to 97% propagates into the deep ocean where it ultimately is absorbed. So as a consequence, the deep oceans actually approximate a Blck body with a total Emissivity of about 97-98%. Since the surface Temperature is in the 270-310 Kelvins, the expected thermal emissions would be centered at about 10 microns, and range from about 5.0 to 80 microns for most of the emitted energy. over most of that range water has very high absorptance, and so the ocean acts quite well as a near black body .
According to Classical Physics, a moving electric charge (Coulombs) comprises an electric Current (Amperes) , and as such it will produce a magnetic field. The acceleration of such a charge is therefore a changing electric current, and a changing magnetic field; and standard Maxwell’s Equations predict that such an accelerated Charge must therefore generate a radiated electromagnetic field. The field equations will generate a “near field” EM field, but at greater distances Depending on the frequency of the changes in the current, there will be a far field which radiates electromagnetic field energy.
That such radiated fileds exist has been know since the time of Marconi and others; and the Physics of efficient EM radiation antenna design over all frquency ranges is well understood; and is central to all modern free filed communications.
At high enough rates of acceleration of electric charges; such as when atmospheric molecules or atoms collide with each other in the course of their “heat” vibrations, the rates of accel;eration are such that the frquencies of the resulting radiated EM fields which are quite calculable from Maxwell’s Equations are best represented as particles rather than waves, and that puts that energy radiated in the form of InfraRed spectrum photon emission.
Youc an talk about the radiation either as LWIR photons; of as Maxwellian Electromagnetif waves; which consist of mutually perpendicular varying Electric and Magnetic fields which are also perpendicular to the direction of propagation of the waves.
The measure of the magnetic component of those fileds will involve the fundamental constant of permeability of free space mu nought, and likewise the measure of the elctric field will involve another fundamental physical constant epsilon nought the permittivity of free space.
Mu nought has the EXACT value 4 pi x10^-7 Volt sec per Amp meter; and epsilon nought has the exact value 8.85418781762 x 10^-12 Ampsec per Volt meter.
Their product has units of sec^2/m^2 ; which is the inverse of velocity squared, and the value happens to be 1 c^2 exactly which also has an exact value 2.99792458 x 10^8 m/s which happens to be the velocity of those Maxwellian radiated Electromagnetic waves; which you seem to be quite happy to dismiss as non existent.
Little did I know when I studied Radio and Ionospheric Physics as one of my Majors that I would have to use it to justify a self evident property of energy and climate/weather Physics.
But feel free to dismiss atmospheric emission of a continuum spectrum of long wave EM radiation if it makes you uncomfortable.
Just because you can’t detect it any way even thoguh the total emittance of such radiation is in the range of 400 W/m^2, is no cause to dismiss it.
One problem with this emission in the case of the atmosphere, is that the effective source impedance is related to the heat capacity of the atmospheric gases which is quite low. So in the course of emitting such radiation the local Temperature of the atmosphere must be lowered. and the only reason that such emission keeps up, is that the energy is constantly replenished either from solar spectrum input energy or LWIR energy input which is captured mostly by the GHGs in the atmosphere.
Liquid sources like the ocean or solids like the rocks and Urban Heat Islands have orders of magnitude greater thermal capacities, so they can radiate energy for longer times without resupply. They still “run down” as is evidenced by the cooling of the surface when the sun goes down.
Evidently it doesn’t strike you as strange that ice is a perfectly good emitter of continuum thermal spectrum radiation at something a bit less than 390 W/m^2 (work the rate out for yourself),a nd even when it melts to become liquid water still at zero deg C is continues to emit at exactly the same rate as the ice; well perhaps the spectral emissivity might be difefrent for water and ice; but then magically when the water turns to vapor at zero deg C, the thermal emission suddenly becomes zero.
Doesn’t sound very plausible to me. Both molecules are moving rapidly so they have accelerated electric charges; and both will produce radiated EM fields that depend on that acceleration and rate of change of acceleration. You can choose to deal with it in the Maxwellian field domain or the optical photon domain as you wish. But simply ignoring it won’t make it go away.
It is instructive to note that Trenberth’s standard exposition of the global energy budget; has a surface emission of 390 W/m^2 which corresponds to just that as predicted for a Black Body at 288 K or +15 deg C. Evidently Trenberth is not convinced that Black Body Radiation is a useless concept in climatology.
As to the emission in a flame a spectral analysis of the light will show that it consists of a thermal continuum and a line spectrum imposed on that background; and the prominet colors that show up are typically the much narrower spectral line emissions; whcih are more intense than the thermal background.
After all, if the gas is ionized then there has to be excited states, as well as a cloud of electrons to revert back to the ground or other lower energy states resulting in a spectral line emission that is characteristic of the gas; not the Temeprature.
I believe what Dr. Robert Clemenzi says on this subject in “How Greenhouse Gases Work” is :
“Nitrogen (N2), Oxygen (O2), and Argon (Ar) have no way to lose heat. (Conversely, they are also transparent to shortwave IR radiation from the Sun and longwave IR radiation from the Earth.) From a completely practical point of view, they are able to lose a small amount of heat, but, at the current rate of heat from the Sun it is not enough to keep their temperature below the boiling point of water.”
He seems to be saying that the minimal ability to lose heat is balanced by a similar ability to gain heat from the sun and that greenhouse gases provide the primary mechanism for cooling the upper atmosphere. I assume this is because the strong radiation-absorption bands of these greenhouse gases are so far removed from the peak solar energy radiation wavelengths. Dr. Roy Spencer made a similar statement in his WUWT article “Earth sans greenhouse effect – what would it be like?” (January 2 2010.)
I believe the ideal black body assumes a continuum of possible energy states each able to absorb or emit photons having that energy. This precludes transparency unless these states have an extremely low probability of absorbing or emitting any photons. I believe that the photon emission and absorption probabilities are related by a microscale time reversal invariance requirement.
The light emitted by a flame may very well be dominated by the line spectra of the combusting materials. I believe there should be a ‘red-hot’ region in the gases rising above the flame, but I cannot ever recall seeing a reddish glow from this area.
Spector says: (October 3, 2010 at 7:04 am)
“I believe what Dr. Robert Clemenzi says on this subject in “How Greenhouse Gases Work” is….”
Correction: I see that my reference to Robert Clemenzi as “Dr. Robert Clemenzi” (above) is unsupported by his document or any other source I can find.
Spector says:
September 30, 2010 at 5:20 pm
“Ionized gases are not transparent. You cannot see through the sun. ”
I was looking (“trolling”) for an answer that involved some quantum mechanics. Perhaps one might say that the solar plasma is hot enough that a collision between an electron and a proton has so many energy levels available to it that the emitted photons form a near-continuum and the putative molecule remains so excited that the particles do not “stick.”
It is not an exact continuum, though, as evidenced by the different graphics on the SDO website.
George E. Smith says:
October 1, 2010 at 3:16 pm
“…magically when the water turns to vapor at zero deg C, the thermal emission suddenly becomes zero.”
I was pleased with this whole discussion. It is gratifying to encounter a comment that is so well-written that the reader actually learns something. One suggestion, however. Water vapor emissions are responsible for the temperature minimum at the tropopause. Also they are the most important greenhouse gas and downward emissions at the surface are largely responsible for the greenhouse effect. So I don’t think you can say that water vapor emissions become zero. Otherwise, an excellent comment.