2010-11-26 23:09:33Stratospheric Cooling and Tropospheric Warming
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Increased levels of carbon dioxide (CO2) in the atmosphere have resulted in the warming of the troposphere and cooling of the stratosphere. This paper will explain the mechanism involved by considering a model of a fictitious planet with an atmosphere consisting of carbon dioxide and an inert gas such as nitrogen at pressures equivalent to those on earth. This atmosphere will have a troposphere and a stratosphere with the tropopause at 10 km. The initial concentration of carbon dioxide will be 100 parts per million (ppm) and will be increased instantaneously to 1000 ppm and the solar insolation will be 385.906 watts/meter2. These two sets of conditions are represented in figures 1 and 2 which were generated from a model simulator at the website of Dr. David Archer, a professor in the Department of the Geophysical Sciences at the University of Chicago. The parameters were chosen in order to generate diagrams that enable the reader to more easily understand the mechanism discussed herein.

Figure 1 shows the Infrared (IR) radiation spectrum looking down at the planet from an altitude of 10 km with a CO2 concentration of 100 ppm and Figure 2 shows the IR spectrum with a CO2 concentration of 1000 ppm. Both figures approximately follow the intensity curve for a blackbody at 300 0K except for the missing band of energy centered at 667 cm-1. This band is called the absorption band and is so named because it represents the IR energy that is absorbed by CO2. IR radiation of all other wavenumbers do not react with CO2 and thus the IR intensity at these wavenumbers is the same as that of the ground. These wavenumbers represent the atmospheric window and is so named because the IR energy radiates through the atmosphere uneffected by the CO2. The absorption band and the atmospheric window is the key to stratospheric cooling.

The absorption band in Figure 2 is wider than that of Figure 1 because more energy has been absorbed from the IR radiation at a CO2 concentration of 1000 ppm that at a concentration of 100 ppm. The energy that remains in the absorption band after the IR radiation has traveled through the troposphere is the only energy that is available to interact with the CO2 of the stratosphere. At a CO2 level of 100 ppm there is more energy available for this purpose than at a level of 1000 ppm, thus the stratosphere is cooler for the higher level of CO2 in the troposphere. Additionally, the troposphere has warmed because it has absorbed the energy that is no longer available to the stratosphere.

One additional point should be noted. Notice that the IR radiation in the atmospheric window is slightly higher in Figure 2. This is because the temperature of the troposphere has increased and in the steady state condition, the total amount of IR entering the stratosphere in both cases must be the same. That total amount of energy is the area under both of these curves. Thus, in Figure 1, there is more energy in the absorption band and less in the atmospheric window while in Figure 2, there is less energy in the absorption band and more in the atmospheric window.

In concluding, it is stressed that no explanation can explain stratospheric cooling without considering the IR spectrum of CO2 as shown in this essay.

        Figure 1. CO2 Level-100ppm, Temperature-0 0C                 Figure 2, CO2 Level-1000ppm, Temperature-2.7 0C

  Two Images

2010-11-27 02:47:32
nealjking

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Two points:

- It would be better to have one figure with the three graphs together: 300-K blackbody spectrum, 100-ppm CO2 and 1000-ppm CO2. The reader would not have to scan & compare two different figures, saving time and possible confusion.

- The IR is absorbed by CO2, but the photons are not "eaten", but are scattered or re-emitted. This is implicit in your statement that the total amount of energy is the same under both curves. However, it would be helpful, I think, to make it more explicit; since a common skeptic argument is that "How can adding more CO2 do anything, since all the IR photons have been absorbed out of the outgoing spectrum anyway?" As I see it, the downward-looking spectrum shows the emission net of absorption and re-emission, so that the bottom level of the absorption band is set by the temperature at the top of the CO2 level of the troposphere.

I believe Riccardo also did a post on the GHE mechanism a few months ago. But I think there's no harm in hitting it from a few different angles: Maybe different readers will find different versions easier to understand.

 

2010-11-27 07:29:06
Bob Guercio
Robert Guercio
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24.187.94.227

Neal,

Thank you for your comments.

I wouldn't know how to combine these two graphs into one.  Can anybody recommend a website where I could get an appropriate graph.  I wouldn't need the same numbers because my writeup could be tailored to the graph, if necessary.

In the steady state, the CO2 molecules are constantly emitting and absorbing photons.  The total energy in the gas remains the same as does the temperature and the energy entering is the same as the energy leaving.  However, when going from a steady state concentration of 100 ppm to a concentration of 1000ppm, photons are absorbed by the CO2, making them more energetic and hotter.  Once the steady state at 1000ppm is achieved, again CO2 molecules are constantly absorbing and emitting but keeping the overall energy content the same.

The photons that are absorbed come from the absorption band and that's why the absorption band is wider at 1000ppm as opposed to 100ppm.

The total amount of energy is the same under both curves because that total amount of energy must equal the light energy entering from above and hitting the ground. If there is less energy in the absorption band there must be more in the atmospheric window and vice-verse.

Are we saying the same thing or different things? If my writeup is not clear, I will change it but first let's agree on a technical understanding of the model.

Also, is there a method of being notified by email when comments are made here? 

Again, thanks,  I am neither a professional writer nor a professional scientist so I certainly could use feedback. 

Bob Guercio 

2010-11-28 01:23:42
nealjking

nealjking@gmail...
76.200.182.175

Graphing: I don't know how you are generating your original graphs, but if you getting a list of numbers as output, you can use Microsoft spreadsheet, Excel, to generate a graph that plots both lists together as two curves.

What is being plotted is radiant power, not energy as such. Global warming has more to do with the reduction of power flux through the atmosphere than with the heat (or energy) content of the atmosphere itself.

From your description, it is not completely clear whether the second graph describes the situation only momentarily after a sudden increase of CO2, or the steady-state condition after a period of adjustment. If the first case, there is no reason to expect the areas under the graphs to agree: The lack of matching IS in fact the warming. If the second case, there should be a match of the areas, but the second graph should be "attempting to conform" to the warmer blackbody spectrum (several degrees corresponding to a 10X in CO2) instead of the 300-K spectrum: The BB spectrum from which it is torn away by gaps is the globally warmed BB.

 

2010-11-28 01:53:02
Bob Guercio
Robert Guercio
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24.187.94.227

Neal,

I generated the graph from David Archer's Website.

In both cases, I meant it to be the steady state so the area under both curves is the same.  Apparently, I need to clarify this.

Neither graph is meant to conform to the 300 degree BB.  It is merely a reference.  I probably would be better off without the 300 degree BB reference but I wouldn't know where to get a graph that meets my needs and I'm not skilled at something like photoshop or the microsoft spreadsheet.

I may have to go with the graphs that I have and just beef up my writeup to explain everything better.

Please let me know if I am understanding your remarks correctly?

Bob 

2010-11-28 02:43:13
nealjking

nealjking@gmail...
76.200.182.175
In that case, I would try to put the two graphs on the same level, so that they can easily be compared in one glance.
2010-11-28 03:28:27
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Neil,

What about your remarks on the area under the curves?  Do you agree that all I need to do is clarify that we are talking about the steady state condition?

Bob 

2010-11-28 04:00:09
nealjking

nealjking@gmail...
76.200.182.175

Yes, I think that's about right. I'll have to look at it again when you've revised it.

 

By "conform," I'm indicating the blackbody background against which the absorption takes place. When the world is a few degrees warmer, the background is slightly (but lawfully) different.

2010-11-28 04:19:50
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Neil,

Please check the second set of figures at the bottom of the blog. The lettering is not as crisp.

Bob 

2010-11-28 07:22:53
nealjking

nealjking@gmail...
76.200.182.175

I would put them side by side.

 

Neal

2010-11-28 11:40:35
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Hi Neil,

Please check just the figures.  Neither is quite complete.  Some lettering left.

I'm leaving out the 300 degree black body curves.  It serves no purpose.

I am going pixel by pixel.  It's laborious.

Thank you,

Bob

2010-11-29 05:30:48
nealjking

nealjking@gmail...
76.200.182.175

Bob,

I would put the two graphs at the SAME LEVEL, side by side, for easier comparison.

 

NE_A_L

2010-11-29 08:15:05
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Neil,

 On my computer, I see them side by side at the same level.

 What do you see?

Are you going to a different URL?  I'm looking at this URL at the very beginning of all these posts.  

 Bob 


http://www.skepticalscience.com/thread.php?t=452
2010-11-29 08:34:14
nealjking

nealjking@gmail...
76.200.182.175

Bib,

 I am going to the same URL; but I see Fig. 2 sitting under Fig. 1; fish-head to tail, as it were.

 

and it's "NEAL", with an "A".

2010-11-29 08:45:12
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Sorry Neal, 

Are you seeing two small graphs in black and white only or are you seeing two graphs with colors? And are you staying on this page?

Bob 

2010-11-29 10:00:43
nealjking

nealjking@gmail...
76.200.182.175

- on this page

- 2 B&W graphs, vertically stacked

2010-11-29 10:17:38
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Could somebody else weigh in on this thread regarding what they see.  I am seeing two black and white graphs side by side.

Is there an explanation for what seems to be happening?

Thank you,

Bob

2010-11-29 12:20:58I see what Neal sees
Daniel Bailey
Daniel Bailey
yooper49855@hotmail...
68.188.192.170

Two B&W graphs stacked vertically.

 

Perhaps check your widths on the graphs and reduce them slightly.

 

Worth a shot.

 

 

2010-11-29 12:52:41
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227

Weird

Let me check on another computer.  And then I'll try that.

Bob

2010-11-29 13:09:54
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.88.102

Hey Guys,

What do you see now?

I'm looking at 2 side by side images but they are smaller.

Bob

2010-11-29 13:46:34
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.88.102

Guys,

Please let me know what you think here.

You have to be seeing two images now.

I put two images side by side on microsoft paint and I saved them as one image.

Thanks again.

Bob

2010-11-29 14:13:13
nealjking

nealjking@gmail...
76.200.182.175

OK, now they're side by side.

Much improved!

 

Neal

 

2010-11-29 15:11:35
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.88.102

Neal,

Thank you,

I have refined the writeup and hope to have everything posted within a couple of days.

Bob

2010-11-30 01:55:17
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.88.102

 

Neal,

Please check this for me.  Ignore the change in font. I'll take care of that.

Thank  you,

Bob

Stratospheric Cooling and Tropospheric Warming
Increased levels of carbon dioxide (CO2) in the atmosphere have resulted in the warming of the troposphere and cooling of the stratosphere.  This paper will explain the mechanism involved by considering a model of a fictitious planet with an atmosphere consisting of carbon dioxide and an inert gas such as nitrogen at pressures equivalent to those on earth.  This atmosphere will have a troposphere and a stratosphere with the tropopause at 10 km.  The initial concentration of carbon dioxide will be 100 parts per million (ppm) and will be increased instantaneously to 1000 ppm and the solar insolation will be 385.906 watts/meter2.  Figure 1 is the IR spectrum from a planet with no atmosphere and Figures 2 and 3 represent the same planet with levels of CO2 at 100 ppm and 1000 ppm respectively.  These graphs were generated from a model simulator at the website of Dr. David Archer, a professor in the Department of the Geophysical Sciences at the University of Chicago and edited to contain only the curves of interest to this discussion.  The parameters were chosen in order to generate diagrams that enable the reader to more easily understand the mechanism discussed herein.

Prior to discussing the fictitious model, consider a planet with no atmosphere.  In this situation light from the sun that is absorbed by the surface is reemitted from the surface.  Figure 1 is the IR spectrum of this radiation which is known as Blackbody radiation.

 

Figure 1. IR Spectrum-No Atmosphere

 

Figure 1

Consider now Figure 2 which shows the Infrared (IR) radiation spectrum looking down at the planet from an altitude of 10 km with a CO2 concentration of 100 ppm and Figure 3 which shows the IR spectrum with a CO2 concentration of 1000 ppm.  Both figures represent the steady state and approximately follow the intensity curve for the blackbody of Figure 1 except for the missing band of energy centered at 667 cm-1.  This band is called the absorption band and is so named because it represents the IR energy that is absorbed by CO2.  IR radiation of all other wavenumbers do not react with CO2 and thus the IR intensity at these wavenumbers is the same as that of the ground.  These wavenumbers represent the atmospheric window and is so named because the IR energy radiates through the atmosphere uneffected by the CO2.  The absorption band and the atmospheric window is the key to stratospheric cooling.

           Figure 2. CO2 IR Spectrum -100 ppm                   Figure 3. CO2 IR Spectrum-1000 ppm

 

Figures 1 and 2 

 

The absorption band in Figure 3 is wider than that of Figure 2 because more energy has been absorbed from the IR radiation at a CO2 concentration of 1000 ppm than at a concentration of 100 ppm. The energy that remains in the absorption band after the IR radiation has traveled through the troposphere is the only energy that is available to interact with the CO2 of the stratosphere.  At a CO2 level of 100 ppm there is more energy available for this purpose than at a level of 1000 ppm, thus the stratosphere is cooler for the higher level of CO2 in the troposphere.  Additionally, the troposphere has warmed because it has absorbed the energy that is no longer available to the stratosphere.
One additional point should be noted.  Notice that the IR radiation in the atmospheric window is slightly higher in Figure 3 than Figure 2.  This is because the temperature of the troposphere has increased and in the steady state condition, the total amount of IR entering the stratosphere in both cases must be the same.  That total amount of energy is the area under both of these curves.  Thus, in Figure 2, there is more energy in the absorption band and less in the atmospheric window while in Figure 3, there is less energy in the absorption band and more in the atmospheric window.


In concluding, it is stressed that no explanation can explain stratospheric cooling without considering the IR spectrum of CO2 as shown in this essay.

2010-12-01 03:46:38Finished I Hope
Bob Guercio
Robert Guercio
robertguercio@optonline...
24.187.94.227
Hi All, Please check this for me. http://www.skepticalscience.com/Stratospheric-Cooling-and-Tropospheric-Warming.html Thanks, Bob