Well now, have all the "parts" been identified?

There is one part that I see which is not seen by others. Who is deluded? Is it me? Could be. But when I ask the question I get no understandable answer. So let's ask the question again.

How far does longwave IR radiation in the 15 micron band penetrate the atmosphere?

My understanding is that ALL the 15 micron band is absorbed within the first few hundred meters of the atmosphere. The absorbed energy will be re-emitted isotropicaly such that something less than half continues up and something less than half returns to the source.

That is the FIRST LAYER. The next layer above will absorb that "half" and send one quarter on up and one quarter back down to the first layer which will pass one eighth on down to the surface and one eight back up.

So from the SECOND LAYER we see so called "back radiation" of 0.5 (one half) plus 0.125 (one eighth) of the energy contained in the 15 micron band that originally left the surface. As we include more layers so the total "back radiation" figure increases but will not exceed 0.7.

Increasing the amount of CO2 or H2O or any "greenhouse" gas will not change that "back radiation" figure but it will reduce the height of the layers where total absorption has occured.

Now logically that implies a certain increase in "heat energy" into say the lowest layer, but it would appear the temperature lapse rate up the atmosphere can obscure this rise along with the natural convection already happening.

All the above applies to a "clear sky" at night. Put a substantive layer of cloud overhead and you get "grey body" radiation back down from the cloud from about 3 microns to 100 microns, which is why local temperature drop on a cloudy night is nowhere near as rapid on a clear night.

(08-08-2010 06:16 AM)Richard111 Wrote:  Well now, have all the "parts" been identified?

Nope, I don't think so, in particular the relationships between the known "parts", it's "the sum" I'm referring to above.
Hence my saying MODTRAN is known to be wrong (global temps / CO2 not doing as predicted by models / MODTRAN),
AND that MODTRAN needs proving to apply to the real, mixed, open atmosphere.

(08-08-2010 06:16 AM)Richard111 Wrote:  There is one part that I see which is not seen by others. Who is deluded? Is it me? Could be.

To a greater or lesser extent we are all fishing in the dark, with misconceptions,
at least we here have the guts to admit it openly.

(08-08-2010 06:16 AM)Richard111 Wrote:  But when I ask the question I get no understandable answer. So let's ask the question again.

How far does longwave IR radiation in the 15 micron band penetrate the atmosphere?

I think this is really the question that we are discussing on this thread,
http://www.globalwarmingskeptics.info/fo...d-794.html

(08-08-2010 06:16 AM)Richard111 Wrote:  My understanding is that ALL the 15 micron band is absorbed within the first few hundred meters of the atmosphere.
The absorbed energy will be re-emitted isotropicaly such that something less than half continues up and something less than half returns to the source.

I am not of the opinion that all IR will be re-emitted, some (maybe most) will be "converted" to something else, ie, sensible heat, or latent heat of vapourisation.
Then it can move vertically (up or down), or laterally, within the atmosphere, in it's new heat energy form, not as IR.
The above linked to thread / discussion seems to suggest that all the IR radiation will be absorbed in a far smaller distance, by water vapour alone.
Also liquid water in the atmosphere emits 15 micron IR, so that it would seem must as well confuse the "picture".

(08-08-2010 06:16 AM)Richard111 Wrote:  That is the FIRST LAYER. The next layer above will absorb that "half" and send one quarter on up and one quarter back down
to the first layer which will pass one eighth on down to the surface and one eight back up.

So from the SECOND LAYER we see so called "back radiation" of 0.5 (one half) plus 0.125 (one eighth) of the energy contained in the 15 micron band that originally left the surface.
As we include more layers so the total "back radiation" figure increases but will not exceed 0.7.

Given my above reply, I'm really not sure about this view at all.

(08-08-2010 06:16 AM)Richard111 Wrote:  Increasing the amount of CO2 or H2O or any "greenhouse" gas will not change that "back radiation" figure but
it will reduce the height of the layers where total absorption has occured.

Again, I think the radiative capacity, or ability if you prefer, of the atmosphere must increase,
with increased so called GHG's, hence increased GHG's would lead to most probably more cooling ability at least.

(08-08-2010 06:16 AM)Richard111 Wrote:  Now logically that implies a certain increase in "heat energy" into say the lowest layer, but it would appear
the temperature lapse rate up the atmosphere can obscure this rise along with the natural convection already happening.

Because of my above given reasons, I do not think that is correct logically.

(08-08-2010 06:16 AM)Richard111 Wrote:  All the above applies to a "clear sky" at night. Put a substantive layer of cloud overhead and
you get "grey body" radiation back down from the cloud from about 3 microns to 100 microns,
which is why local temperature drop on a cloudy night is nowhere near as rapid on a clear night.

As I've suggested several times recently I think the cloud layer reduces convection, so the conducted heat stays around longer at lower levels.
This could be "misinterpretted" as "back radiation" heating of the surface / lower layers, but I do not think it is.
My reduced convection suggestion also explains why the air becomes more moist / humid at lower levels,
the conducted heat, and vapourised water simply hang around at lower levels for longer, or rather convect upwards (or diffuse only) slower.

Regarding MODTRAN (4) software -

http://www.kirtland.af.mil/library/facts...sp?id=7915
Excerpts,

MODTRAN - MODerate spectral resolution atmospheric TRANSsmittance algorithm and computer model

Access to MODTRAN4 requires that a new Non-Disclosure Agreement (NDA) be signed and a fee paid.

Military, model, algorithms, none disclosure.
Alarm bells ringing anyone ?

I would also note the use of words and phrases like,

" It remains the state-of-the-art "

" development of MODTRAN was driven by a need for higher spectral resolution and greater accuracy than that provided by the LOWTRAN "

" The current release is MODTRAN4, version 3.1. This version number connotes the additions of
some errata and new physics since MODTRAN4 was first patented and released. "

" now having a physical meaning. "

" permit more accurate calculation of molecular absorption "

" The updated Rayleigh scattering algorithm models the spectral dependence of the depolarization factor, and
the refractivity (equal to one minus the real part of the index of refraction)
now varies not only with water density but also with CO2 partial pressure. "

I will redo this after my present shift, and maybe start a thread from it,
but I want to get something down now, whilst the train of thought is still fresh in my mind.

I originally started this thread because of a comment Mike Davis posted, he commented that
the David Archibald plots of the log effect of CO2 are very questionable. I asked him to expand upon this, but he has not to date.
Having been well aware of the importance of the David Archibald, (and the IPCC's version) plot of the effect,
I decided to delve (as best I can) a little myself, and this thread is the result.

In the end MODTRAN is a model, that's all, a "climate model".
The user can play with the model, to get the results..
Once you have access to and know about what MODTRAN does you can not divulge it - none disclosure "agreement".
This does not appear to me to be open or good science,
certainly you can not apply the scientific method to the results derived from, or including MODTRAN.

The "model" is now MODTRAN 4 version 3.1. Earlier versions were apparently very poor.
Earlier versions were so inferior, the latest model now boasts in some respects " having a physical meaning. "
" New physics added "......
Which version did David Archibald (and the IPCC) use. ?
Would the present version give the same results. ?

We describe GCMs as GIGO (garbage in garbage out), but just look at MODTRAN it's at best not very good.
It is to all intents and purposes a virtual reality. A bit like Gran Turismo on the playstation really,
yeah it has some of the cars in a vaguely realistic manner,
but the bigger picture, the scenery, well, just don't go there..
But it is the basis of so, so much, not just the log. effect of CO2.
It is the "physics" of climate models, and all those pro AGW "thought" experiments, and the global energy budgets, to name just a few.

Way back in the dark ages, when the flat earth dogma refused to die,
it was thought that the earth was flat and it rested upon a turtles back.
Some tried to argue it was sixteen turtles as if this gave the discussions more creedance...
Now we have a flat earth society, it is AGW, and their "turtle" is MODTRAN.

What also occurs to me is that almost all the main mainstream skeptics I can think of,
all, quote and use MODTRAN........
I have said before they only seem to quibble the figures, not argue the physics,
well, they never question MODTRAN do they. Why ?

To me this smacks of the oldest trick in the book, control both sides of the debate.
The main skeptics are reliant upon MODTRAN, anyone who isn't isn't worth listening to.
So, the debate is only between MODTRAN proponents - is it any wonder they only quibble the figures.......

It is a mistery to me (given the above it isn't really) why there has not been a MODTRAN debate.
In fact it is a traversty, that the debate has not happened, it must of,
and it must still be going.....
I havn't heard of it though, have you ?

I've been reading Roy Spencer's blog and am becoming disheartened.

Everyone seems to talk about greenhouse gases in the atmosphere absorbing radiation as though they are solid bodies. Greenhouse gases are selective and can only absorb a very small percentage of the IR radiated from a solid surface. Not once, on any blog, have I come across any reference to how much energy is available in the 14 to 16 micron band in relation to the total grey body radiated energy.

People talk gaily about so many watts per square meter for such and such a temperature but never, ever, define the energy actually absorbed by CO2 in relation to the total energy passing through the atmosphere.

Your spot on Richard111, "they" only talk of the MODTRAN modelled / derived "facts and figures".....
AND, "physics".

(08-10-2010 10:23 AM)Richard111 Wrote:  I've been reading Roy Spencer's blog and am becoming disheartened.

Everyone seems to talk about greenhouse gases in the atmosphere absorbing radiation as though they are solid bodies. Greenhouse gases are selective and can only absorb a very small percentage of the IR radiated from a solid surface. Not once, on any blog, have I come across any reference to how much energy is available in the 14 to 16 micron band in relation to the total grey body radiated energy.

People talk gaily about so many watts per square meter for such and such a temperature but never, ever, define the energy actually absorbed by CO2 in relation to the total energy passing through the atmosphere.

You are absolutely right!
Looking at the absorption spectra for CO2 and water it is clear that the IR outside of the bands in their absorption spectra passes through the atmosphere unimpeded (except possibly by dust!)

One would need to use a spectrometer to gather data on the IR spectra that is emmitted from various surfaces of the earth. (desert, grasslands, forests, the sea, Ice, tarmac and buildings {urban areas}) etc



As you can see, the majority of absorption and scattering is due to water vapour and overlaps two of the three CO2 bands. One completely and one partially, there is only one IR band for CO2 that sticks out on its own.

But we need to compare this to the IR spectra emitted by various types of ground.

The following graphs are from the online version of MODTRAN:
http://geoflop.uchicago.edu/forecast/doc....orig.html

Whilst it may not be as 'accurate' as the latest version, it is unlikely to differ to an extent that the general trend is significantly changed. Thus there is no real doubt that, for levels of CO2 that are feasible in the real world, the law follows a log type law.

Very nice graphs Q_C, thanks.

I think I am beginning to see where the problem is. Note the IR scales seem to imply total IR (BB IR) is being absorbed. This is not so. At no time during the past 200 years or so has the planet been totally covered in cloud and or volcanic dust. The "window" is always open to a more or lessor degree. Atmospheric absorption is complete within the first hundred meters or less and is almost completely thermalised. The air that has been so warmed will already be part of the rising convection cooling process that far outstrips the warming. In effect the surface IR radiation is IMPROVING the the CONTACT AREA of the gas/solid interface. i.e. it is making conduction from the solid to the gas more efficient.

The CO2 in the atmosphere, even just ten meters up, is already much cooler than the surface and IR radiation is proportional to the fourth power of the temperature. The so called "backradiation" is real but miniscule and constant. It does not change for HUGE variations of water vapour (H2O) and neither does it change for those minute changes of CO2 as recorded by the hard working Keeling over at Mona Loa.

(08-27-2010 12:58 PM)Questioning_Climate Wrote:  The following graphs are from the online version of MODTRAN:
http://geoflop.uchicago.edu/forecast/doc....orig.html

Whilst it may not be as 'accurate' as the latest version, it is unlikely to differ to an extent that the general trend is significantly changed.
Thus there is no real doubt that, for levels of CO2 that are feasible in the real world, the law follows a log type law.

Bold my emphasis.


Am I right to assume you mean,
Given "we" (blindly) accept the (requires proof) physics in an open and mixed atmosphere (requires proof/s applies as measured and simply summed together from closed and individual systems)
as then further modelled by MODTRAN (which also requires proofs that it has all the relevant factors / relationships / combinations correctly modelled)
thus there is no real doubt that,
for levels of CO2 that are feasible in the real world, the law follows a log type law.

I strongly suggest "we" can not be sure at all, it could easily be the exact opposite, or no effect at all.

I do not know what to make of " the law follows a log type law ".
Does this mean to suggest the log. effect of CO2 upon atmospheric temp is a law. Surely not.

Derek,

Yes, thank you, your rephrasing is more accurate.

Let me put the record straight:

The shape of the MODTRAN relationship between CO2 in the atmosphere and out-going IR radiation is approximately logarithmic. On the log/lin plot, it is almost a straight line which indicates a log type relationship.

It is not possible to ascertain from the model output whether the absolute values are correct or that the underlying physics is valid. All that can be said is the programmed law yields a logarithmic response and on the basis of that MODTRAN law, atmospheric CO2 is presently well away from the high sensitivity region.

(08-29-2010 12:35 PM)Questioning_Climate Wrote:  All that can be said is the programmed law yields a logarithmic response and on the basis of that MODTRAN law, atmospheric CO2 is presently well away from the high sensitivity region.

Absolutely. My only query is are those MODTRAN graphs specific to IR absorbed by CO2 ?? One has to assume so. There seem to be no great changes in absorbed radiation or reduction in outgoing IR for a doubling of CO2.

The more I see and the more I learn the more convinced I am that CO2 has no marked effect on climate. The new studies relating to the sun's magnetic output and UV changes during solar cycles easily account for global average temperature changes. The UV changes alone can account for ocean heat levels even under partly clouded conditions.

Back to CO2; it has been pointed out that warm air does not rise against gravity of its own accord. It is pushed up by more dense air moving in underneath. I would also suggest that CO2, being a markedly massy molecule, will tend to pool as this happens. This will add to low level absorption of IR and shielding of the upper air. This absorbed energy is thermalised and any "back radiation" from CO2 anywhere in the atmosphere can only be at the level of the local air temperature. Remember, the level of radiation is proportional to the fourth power of the temperature in degrees Kelvin. Heat energy is conducted up through the atmosphere via conduction/convection and follows the lapse rates discovered over 100 years ago. The so called huge increase due to man made CO2 production does not and cannot change these lapse rates.

Richard111,

The data was obtained by changing CO2 levels in the model and keeping all else constant.

I think gravitational effects on CO2 will be swamped by turbulent mixing through convection.

Hi All,
For other reasons, I have been looking up the basics of flowcharts.
Please see attached.

I came across,
http://www.nos.org/htm/basic2.htm
NOS : Certificate in Computer Applications
LESSON 25

Excerpt,
" Flowcharts are generally drawn in the early stages of formulating computer solutions.
Flowcharts facilitate communication between programmers and business people.
These flowcharts play a vital role in the programming of a problem and
are quite helpful in understanding the logic of complicated and lengthy problems.
Once the flowchart is drawn, it becomes easy to write the program in any high level language.
Often we see how flowcharts are helpful in explaining the program to others.
Hence, it is correct to say that a flowchart is a must for the better documentation of a complex program. "

and, from,
http://www.tpub.com/neets/book22/93b.htm

" To construct a flowchart, you must know the symbols and their related meanings.
They are standard for the military, as directed by Department of the Navy Automated Data Systems Documentation Standards, SECNAVINST 5233. "

It is simply the case then that flowcharts are used "as standard" by the American military, and
that they are accepted as being particularly useful (read necessary) in communicating how
complex computer models work to a wider audience than just computer programmers.

So, from this it would be reasonable to assume that there are flowcharts of how MODTRAN works,
and,
some of these flowcharts MUST BE very, very detailed.

I doubt anyone really could get an understanding of what the MODTRAN software models by watching the program run.
Some people maybe able to glean some meaning from the equations that the model uses, possibly.
But many, many more would get a far better understanding of what, and how MODTRAN does with a flowchart.
Do these flowcharts exist. ? According to the above they must.
Has anyone see one. ? Not that I'm aware of.
Which is, when you think of it, rather glaringly NOT OPEN OR GOOD SCIENCE.

I would of thought that James Hansen MUST have seen such flowcharts, I would also be surprised if Roy Spencer had not seen them, and
I would further suspect Richard S Courtney (an accomplished computer model tester) must also of seen such flowcharts.
[It's not often you see those three names in one sentence, is it...]
It would be reassuring to think that, in the context of this thread, David Archibald had also given such charts at least a "once over".

But yet, "we" do not get to see, or get the opportunity to question these flowcharts,
that I would suggest MUST exist, as surely as the global climate is naturally variable.....

Yes, flow charts have their place but they are not science. They can also very easily mislead. Look at all the different global energy budget charts. Okay, okay, they are not computer program flow charts, but same reasoning. I did two years of computer programming in uni back in the late eighties and royally screwed myself up at times with my flow charts.

Turbulent mixing can also be a misleading term as people unfamiliar with thinking about the atmosphere assume it effects all levels. It is mostly low level or cloud induced. I know, I used to fly in the stuff. I much preferred the smooth layers.

Back to my new bugbear. At 7,000 meters the adiabatic temperature is about -30C.

Now that is cold. It gets colder as you go higher. (at least until the tropopause) Now look at the Maxwell_Boltzmann chart I posted over at Layman Struggles. I think I can safely say well over 90% of the air molecules, N2 and O2, are well below the energy level to excite a CO2 molecule to give off a photon. Thus the (well mixed ) CO2 molecules can't aquire enough kinetic energy to radiate unless they happen to encounter a molecule at the 10% or less, high energy, end of the scale.

My point is that at that height in the atmosphere over 90% of the CO2 molecules are actually INHIBITED from radiation!

I think this effect is logarithmic as altitude increases. The way I see this is any radiation from CO2 is mediocre at low levels, first hundred meters or so to totally absent above. Why? Because the CO2 molecule can absorb energy but because of the sluggish behaviour of the cooling air molecules the absorbed energy is thermalised and becomes part of the normal adiabatic process.

(09-25-2010 12:05 AM)Richard111 Wrote:  Yes, flow charts have their place but they are not science.

I did not mean flowcharts ARE science.
I meant to say they must be used to explain more openly the science of how, and what is contained within and modeled by the computer program MODTRAN.
In that respect I think I am correct.

(09-25-2010 12:05 AM)Richard111 Wrote:  They can also very easily mislead. Look at all the different global energy budget charts.
Okay, okay, they are not computer program flow charts, but same reasoning.

I agree, but the point I am trying to make (my apologies for repeating it) is that they SHOULD OF BEEN used to try to explain better.
Especially, as this is standard American military procedure.

(09-25-2010 12:05 AM)Richard111 Wrote:  Back to my new bugbear. At 7,000 meters the adiabatic temperature is about -30C.

Now that is cold. It gets colder as you go higher. (at least until the tropopause)
Now look at the Maxwell_Boltzmann chart I posted over at Layman Struggles.
I think I can safely say well over 90% of the air molecules, N2 and O2, are well below the energy level to excite a CO2 molecule to give off a photon.

Thus the (well mixed ) CO2 molecules can't aquire enough kinetic energy to radiate unless they happen to encounter a molecule at the 10% or less, high energy, end of the scale.

My point is that at that height in the atmosphere over 90% of the CO2 molecules are actually INHIBITED from radiation!

I have been struggling to grasp this basic point you have been patiently making correctly for some time now.
Thank you for persisting, it is beginning (and the ramifications of it), to sink in.

(09-25-2010 12:05 AM)Richard111 Wrote:  I think this effect is logarithmic as altitude increases.
The way I see this is any radiation from CO2 is mediocre at low levels, first hundred meters or so to totally absent above.
Why?
Because the CO2 molecule can absorb energy but because of the sluggish behaviour of the cooling air molecules
the absorbed energy is thermalised and becomes part of the normal adiabatic process.

Eureka for me I think, too..
If I may ask you then, what does emit the IR that escapes to space, and from what hieght mostly. ?
Presumably something emits at about earth's overall temp of 15 celcius, but how at minus 30 celcius. ?

I am thinking this is the "problem" that the atmospheric temp profiles deal with in their representation of hieght / altitude, versus temp.
The temp we would experience is about minus 30 celcius, but is actually sparsely distributed "stuff" at a greater temp, or rather energy level.
Put another way the CO2 at minus 30 is not at minus 30, it just would feel like that to us.
The CO2 is at a higher energy level / temp, but lower pressure, so we would experience lower temp.

The question is WHERE do they measure the outgoing radiation and how.
The fact that CO2 has absorbed and thermalised its fingerprint band of IR will not have much effect if they are trying to record temperature. Also any clouds or high level ice crystals will reflect IR from the warmer stratosphere and mask any missing IR bands.

I have another post on Layman Struggles where I claim backradiation is efectively nonsence.