REDUX: What?  Downwelling IR Radiation   Why?  Condensation Nuclei and/or Cloud?   How?  Tyndall Scattering and/or Downwelling IR Emission?

The posting (with the same title on September 7)  was taken removed for further review at Jerry L Krause’s request while he reexamine one of his premises.  He has brought it back with comments, changes and dialogue which I think you will find most interesting.  So,  be enlightened, entertained and take his challenge.


Guest Posting by Jerry L Krause   2017

Author’s Note:  A fact is that CB posted my previous essay with a very similar title which contained a gross error.  He offered to take down this essay but I consider even a greater error is to hide one’s errors.  Buckminster Fuller considered we can only learn from our errors.  For just because an idea worked when tested in a given situation, it might have worked for a different reason (idea) than that being considered.  So, he concluded it is very important for humans to share with others that which they clearly have found does not work.  Because of the gross blunder I had recognized, I began to ponder what other errors I might have made.  And I have concluded there were.  So while the title is similar, it needed to be modified a bit.  So, I concluded that the beginning of my essay needs to be totally different.

At some early time I believe prehistoric people observed clouds to frequently form and dissolve again, without any precipitation occurring, just as we do today.  And from the beginning I believe all human babies began to drink their mother’s milk in order to survive.  And later in these babies’ lives many began to drink the milk produced by other animals as I have.  So what these early humans, and many since, likely have observed, if they noticed things, applies to the natural phenomenon we term Tyndall scattering or the Tyndall effect or colloidal scattering

But it is an all too common observation that we don’t notice common everyday observations (things).  To support this idea, I ask a few questions which only each individual reader can answer.  First, do you know what the phenomenon we term the Tyndall scattering (etc.) is?  If your answer is: no, you cannot know what these prehistoric people could have seen that could have been related to Tyndall scattering.  If yes, the second question is: do you know how, what these prehistoric people could have seen, applies to the natural phenomenon of Tyndall scattering?  And if your answer is no, you cannot know how this natural phenomenon applies to the observation of the invisible (to our eyes) downwelling longwave infrared (IR) measured by an instrument of the SURFRAD project at seven locations in the USA.  And if your answer is yes, do you know how this natural phenomenon applies to the observation of the invisible (to our eyes) downwelling longwave infrared (IR) measured by an instrument of the SURFRAD project ( at seven locations in the USA?  And if your answer is yes, you can read what follows and help me discover any errors which still exist by making comments.

First we need to accurately define a few words.  A characteristic feature that distinguishes colloids from solution is the Tyndall effect.  When a beam of light is passed through a true solution, the path of the beam is not visible from the side.  The dissolved particles are too small to scatter light, and therefore the light goes on through.  In a colloid, the particles are big enough to scatter the light.  Therefore, when a beam of light is turned on a colloid, an observer at one side can see the path of the beam. (Chemistry 5th Ed. by Sienko and Plane)

Next, we need to briefly review certain knowledge of R. C. Sutcliffe, an experienced meteorologist.  Clouds which do not give rain, which never even threaten to give rain but which dissolve again into vapor before the precipitation stage is ever reached, have a profound effect on our climate.  … The clouds themselves emit heat as though they were black bodies. … These results, obtained first by Wilson and broadly confirmed by many later experimenters, have a very important bearing on natural meteorology, not because supersaturation occurs in the atmosphere but because it does not occur:  why is it that in the atmosphere condensation to clouds invariably happens as soon as normal saturation is reached?  The answer is that the natural atmosphere, however clean it may appear to be, is always supplied with a sufficient number of minute particles of salts, acids, or other substances which serve just as well as liquid water in capturing water molecules from the vapour.  These are the ‘nuclei of condensation’, and are effective as soon as the air becomes even slightly supersaturated.  As a matter of fact, there are many observations of clouds in air whose relative humidity is considerably below 100 per cent, evidence of nuclei which are hygroscopic. (Weather and Climate, 1966)

First, without C. T. R. Wilson’s famous experiments with his expansion cloud chamber (which Sutcliffe did briefly reviewed) we would not know that atmospheric ‘condensation nuclei’ were a necessity for clouds to form and then to dissolve again into vapor before the precipitation stage is ever reached.  However, Sutcliffe never acknowledged that after the clouds dissolve that condensation nuclei must remain.  Sutcliffe never describes the condensation nuclei as being mini cloud droplets which do not scatter, to the side, the white light of the sunshine into our eyes.  Hence this white light by which we see clouds must, by definition be due to Tyndall scattering. So in turn we must consider cloud droplets to be colloidal particles.  However, condensation nuclei as described by Sutcliffe must also be colloidal particles because they seem to be much larger than the molecules of nitrogen and oxygen which are the major components of the atmosphere which keep the larger mini, and even larger, cloud droplets suspended in the atmospheric solution.  But, we cannot know why we cannot see any evidence of the condensation nuclei after the cloud droplets dissolve again into vapor.

This is where possible observations of natural milk become important.  Possible because most people today are not familiar with natural milk, so they cannot know what happens when natural milk is allowed to set unstirred for several hours.  This even though they might be familiar with the common saying:  The cream always rises to the top.  ‘Whole’ milk is generally white or slightly ‘tannish’.  Most natural cream that I have seen is definitely tannish or yellowish.  The ‘skim’ milk, without cream, is definitely blueish and definitely not white as the whole milk was and is.  And, as I have suggested prehistoric people could have more likely noticed these color differences even though they had no idea of why or how.

Now a fact is that Richard Feynman explained his theory of why and how to his Introduction to Physics students at Caltech during the academic year 1961-1962.  (The Feynman Lectures on Physics)  Except, he never identified, by name, the scattering of light observations he was explaining.  And I, since that time, have seldom, if ever, read any physicist who considered the existence of Feynman’s theory or that there exists a theory which explains the why and how of the long known Tyndall scattering.  Which as just reviewed is not always even identified (Tyndall Effect) as a natural scattering phenomenon.

The simple result of Feynman’s scattering theory is that the scattering ‘intensity’ is strongly dependent upon the size of the scattering particle (colloid).  The intensity increases as the size of the scattering colloidal particle increases.  Hence, one can easily see the white solar radiation scattered by cloud droplets.  And one cannot see any evidence of the remaining, smaller, condensation nuclei.  The smaller ‘milk solids’ of skim milk do not scatter the warm colors of the solar spectrum as strongly as the larger ‘fat’ particles of whole milk or cream do.  These long known observations strongly support, but do not prove, Feynman’s scattering theory.  And as part of his lecture, Feynman clearly and simply stated that increase of scattering intensity rapidly increased as the size of the scattering particle increased up to the point where the wavelength of the radiation closely approached the size of the particle.  Hence, according to Feynman’s theory, cloud droplets with the ordinarily size (20 microns) scatter shortwave IR radiation much more strongly than they scatter red light, and these droplets scatter the longwave IR radiation even much more strongly than they scatter the shortwave IR radiation.

Do you see how prehistoric observations strongly support the generally unrecognized theory of Feynman?

But I have not yet directly addressed the central topic of this essay.  Which is to correct my blunder by offering figures of data which do show that cloud do influence the measured values of Downwelling IR radiation

Figure 1

I challenge anyone to offer an explanation for a cause, other than cloud, of the sudden increases in the measured values of  DWIR (Fig 1) which occur between 12am and 1am and then again at about 3am and do not ignore the little blip seen between 9 pm and 10 pm.  For the corresponding blip in the UWIR radiation slightly later is evidence that it is not instrument caused, because two instruments are involved, but also that the sometimes influence of cloud which causes a warming of the surface atmosphere is seen.

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

I believe that Figures 1 through 7 well establishes the influences of cloud upon the measured values of DWIR radiation and that no further explanation of what can be seen is necessary.

While our consideration of the SURFRAD data is not complete, I am not going to make another error which I have been making.  My wife likes to ask children:  How do you eat an elephant?  And when they do not give her answer, she gives them her answer:  One bite at a time.

I am writing an essay and I forget I am not writing a book.  Therefore, I have commonly not written bit sized pieces of information because there is always more information which needs to be addressed.  So in the next essay I will address the measured Diffuse Solar radiation.

2 responses to “REDUX: What?  Downwelling IR Radiation   Why?  Condensation Nuclei and/or Cloud?   How?  Tyndall Scattering and/or Downwelling IR Emission?

  1. The downwelling readings don’t make sense. Clouds can make a difference of 10C on a night with or without clouds.

    • Alan

      I plan to forward your comment to Jerry. He may wish to respond. If so I will publish it.

      Perhaps you might wish to reword you comment specifically the “Clouds can make a difference of 10C on a night with “or without clouds”

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s