I think you are making a simple explanation difficult. The question for AGW to be determined is

“Do rising levels of atmospheric CO2 cause global warming?”

The point is: Global Warming is measured at or near Earth’s surface, ie where we live. Why do you and others make complicated model calculations, etc from satellite measurements when one has simple surface-based measurements available. Perhaps it’s because the ground-based types do not match AGW.

My site shows simple methods which do match ground-based data. Additionally, Chapter 1a shows quantitatively that satellite IR data MUST be in error.

]]>But remember what I included, and that is that when water at the surface is disturbed and and water that goes from liquid to solid and water that goes from gas to liquid releases photons of energy. I surmise that when water changes phase from gas to liquid and from gas to solid, in the upper atmosphere, that the photons have 180 degrees, at least, to radiate toward space. This will get rid of heat. Water at the oceans surface, that is violently shaken and disturbed by tidal and wind currents, will eventually settle back to calm, or enough for at least to restore the hydrogen bonds that were broken when the surface was disturbed. Photons will be released. In this case, probably many photons will be reabsorbed by the water; however, I can’t imagine that some would not escape. This is not in the literature, and you are getting a little taste of my original thinking.

I mentioned in an earlier post that wavelength can be converted to frequency. It is by the relationship c=fλ. (I skipped using nu for frequency and used f instead.) Then by using the calculated frequency for each wavelength, we can use Einstein’s photoelectric effect to calculate the energy of the wave. E=hf, where h is 6.6262 x 10^-34 Js. I surmise the atmosphere is thick enough with a concentration of 400 ppm of CO2, that the small portion of terrestrial radiation produced to excite the CO2 molecule to a higher quantum state, will excite all the molecules. If it does not, then the temperature rise will be less, not more. I don’t plan on winning the Nobel Prize for this, as it was Einstein’s only one. But it is correct and sufficient for coming up with the answer. I do see one thing that my method does and that is that it assumes all terrestrial radiation of the wavelengths that CO2 absorb (on average), are all absorbed by CO2. I don’t include the flux in this case or the Watts sr^-1cm^-2. This would be required if I did not make such a bold assumption, and it would satisfy the need for spectral line strength. But my assumption will result in an over estimate, not an underestimate.

One last note, on a black body emitter, the temperature would have to be 193 K for it to emit IR waves at 15 micrometers, so at this point the earth is warmer than that and the 15 micrometer wavelength should not heat the earth’s surface. However the 2.7 and 4.3 wavelengths have ample energy to heat the surface and the 2.7 is very close to the resonance wave that is needed to break the hydrogen bonds in water and ice. Those are probably the 2 wavelengths responsible for carbon dioxides greatest impact and synergistic effect with water. However, when water condenses or undergoes deposition in the troposphere, when snowflakes and ice crystals are formed higher up than that, these waves will be emitted and have more than a 50% chance of escaping upward, as opposed to radiating back downward.

]]>I am confused on how line strength plays into the whole scenario.. All atoms (usually in the gaseous phase) can absorb a photon of energy and become excited by having their valence electrons rise to a higher energy state or principle quantum state, around the nucleus, in the electron cloud. When the electrons fall back down to the ground state that they started from, the atom will emit a photon of energy. Molecules have this electronic energy level as well as two other energy levels (rotational and vibrational). Each energy level can absorb a photon of specific energy in order to become excited, from an initial quantum state to a higher energy quantum state. When the energy state returns to it original value, (ground state) a photon of energy is released.

One absorption line is centered on one frequency, v. What is the chance of a photon of frequency v getting absorbed when it passes through a gas with n molecules? This is where the line strength comes into the equation.

..They say water and CO2 together act to amplify the greenhouse effect; however, quantum mechanics can show the opposite is true..

The mechanism is very different from what you probably think is the mechanism because quantum mechanics doesn’t show the opposite is true.

Basically more CO2 leads to a higher temperature. A higher temperature evaporates more water into water vapor. Water vapor is a greenhouse gas as well as CO2 (see note at end).

If “*quantum mechanics can show the opposite is true*” it would need to show that doubling the concentration of a gas (that absorbs) will lead to **less** absorption. Quantum mechanics doesn’t show that.

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Finally, not having understood what line strength is, or solved the equations that you apparently endorsed by linking to a powerpoint that contained the key equations, you conclude by hand-waving argument that “stuff” (possibly climate science basics on the greenhouse effect, possibly a confused idea about climate science basics, I can’t be sure) is “not even right”.

When **you** work through the derivation of the equations you will come to understand the significant of the line strength. When you solve the equations – which you need a computer for – with the database of CO2 lines you will find that yes, this basic idea is about right.

Or – a “Blue Peter badge” (English history here) or even a Nobel prize awaits your revising of the Schwarzschild equations, or your solving of them to produce a completely different result from that which everyone else has found.

As a side note, I followed the derivation of the equations to my own satisfaction (from textbooks and papers), got access to the HITRAN database, wrote a Matlab program to calculate the effect and got basically the same result as climate science papers on this subject. No surprise.

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Note: the complication in water vapor as a positive feedback involves the turbulent flow of the atmosphere. It’s clear that higher air temperature at the surface of the ocean leads to more evaporation. This is basic physics. But water vapor at the surface doesn’t really have any effect on the “greenhouse” effect. It is upper tropospheric water vapor that really has the effect. So the connection is no longer “basic physics” but solving turbulent flow. More in the Clouds and Water Vapor series.

Temperature does come into the absorption data in a way I explain in the “note on line strengths” below. I explain in a “footnote” because that wasn’t the point I was making.

It is always difficult to convey a complex set of ideas in a single paragraph, which is why I pointed you to a series. Of course, why bother reading it when you already know the answers?

This is my last attempt to convince you that you are missing physics basics..

To calculate absorption requires:

– the incident radiance at each wavelength

– the line strength (the absorption data) at each wavelength given the concentration of each GHG

To calculate emission requires:

– the line strength (the absorption data) given the concentration of each GHG

– the temperature of that layer of the atmosphere

The radiation balance (“the radiative transfer”) is a balance between emission and absorption and therefore the temperature profile of the atmosphere is required.

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*Note on line strengths*: the line strength itself (of each absorption line) is not a function of temperature, but absorption in practice is not an infinitesimally thin line. Instead, it is a curve broadened by a number of factors, mostly, in the lower atmosphere, by collisions (the Lorenz line shape). This broadening affects absorption and is dependent on temperature and pressure.

Pressure varies much more significantly than temperature as you move vertically through the atmosphere, so pressure is much more significant than temperature.

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At this point I don’t think there is a lot of point responding further. You are very confident that you know the answer and just want to tell me what you know.

If you want to engage, then explain what is wrong with:

a) the equations in Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Six – The Equations – the equations of radiative transfer including the plane parallel assumption, and

b) the effect of temperature and pressure on line shape explained in Visualizing Atmospheric Radiation – Part Six – Technical on Line Shapes.

If you think they are correct then explain why temperature is not important.

I reference physics textbooks and papers in the articles already linked. None of these basics are in dispute in physics and spectroscopy.

However, the powerpoint you reference also refers to the Schwarzschild equations. The equations in Understanding Atmospheric Radiation and the “Greenhouse” Effect – Part Six – The Equations are the Schwarzschild equations.

I suggest that you don’t understand the relevance of these equations. (Further technical note: I haven’t reviewed your powerpoint for accuracy).

And to answer my earlier question “What database for absorption lines did you use?” – I answer the question for myself – what database did I use?

I used the HITRAN database of the absorption lines. Each line, at each wavelength, has a different strength, and also some other different parameters.

There are about 300,000 CO2 lines in the HITRAN database (and 2.7M absorption lines in total).

Reference: The HITRAN 2008 molecular spectroscopic database, by L.S. Rothman et al, Journal of Quantitative Spectroscopy & Radiative Transfer (2009).

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Please take the time to read the material already linked. Or don’t. I’ll probably ignore further comments that don’t reference this material.