onsdag 16 januari 2013

Fiction (or Fraud) of Infrared Radiance Sensing

The existence of a greenhouse effect GHE is being documented by the reading of an infrared detector supposedly recording a radiance spectrum (in W/m2 per wave number). The radiance spectrum of outgoing long wave radiation OLR over Sahara measured by the IRIS satellite shown above as the black curve has a ditch around wave numbers 667 with reduced radiance characteristic of an emission temperature of 220 K.

The ditch is connected to the absorption/emission spectrum of CO2 which peaks at 667 with a total effect of about 10% reduction of OLR. The infrared detector thus reports a substantial effect (10%) of the atmospheric trace gas CO2 on the radiation balance of the Earth as if the presence of a small amount of CO2 (0.036%) in the atmosphere could "block" up to 10% of the radiation from the Earth represented by the ditch.

The scientific evidence of the "warming effect" of atmospheric CO2 is thus the radiance spectrum produced by an infrared detector (pyrgeometer, bolometer, interferometer) , and to understand the validity of this evidence, we have to understand the design of an infrared detector. 

In a sequence of posts on infrared thermometers connecting to an earlier sequence on the myth of back radiation, I have shown that what the infrared detector effectively detects is the temperature of an object in radiative contact with the detector. It is like a fever thermometer put into your mouth recording the temperature of the interior of your mouth by direct contact, only acting at distance by radiative contact. You don't try to measure the variation with time of the flow of heat energy from your mouth into the thermometer by carefully recording exactly how the temperature increases to its final maximal value with time, because you don't know what to do with this information and since it obviously can depend on how the thermometer is positioned, you see no meaningful use of such a measurement. In short, measuring temperature is possible and meaningful, while measuring heat flow is difficult and of questionable value.  

The fact that an infrared detector in principle is a thermometer detecting temperature is acknowledged in e.g. Exploration of the Solar System by Infrared Remote Sensing by Hanel et al:
  • One class of thermal detectors depends on the temperature rise in the detector element caused by the absorption of infrared energy. The resulting temperature difference between detector element and surrounding heat sink is then registered by electronic means. Detectors based on this principle are called thermal detectors; they are more or less sophisticated thermometers. 
A infrared detector thus detects temperature, in the above radiance spectrum a temperature of 220 K around wave number 667 from the presence of atmospheric CO2 of temperature 220 K in radiative contact with the sensitive infrared detector in the IRIS satellite looking down to the Earth and detecting a trace gas absorbing/emitting in a narrow frequency band.  

But an infrared detector not only reports temperature, but also radiance and to properly understand the reported radiance spectrum, the step from temperature reading to radiance spectrum must be understood. 

The above graph shows how this done: The dotted curves show the spectra of an ideal blackbody at different temperatures. We see that the recorded temperature of 220 K is translated to radiance as if the atmosphere with the trace gas CO2 was an ideal blackbody of temperature 220 K in the range of the ditch. 

But this an ad hoc assumption. The emissivity of the atmosphere with the trace gas CO2 is not equal to that of an ideal blackbody (=1), but is unknown. And there are no independent measurements of the emissivity of the atmosphere that can compensate this lack of knowledge.

The emissivity is unknown and thus the radiance spectrum constructed from temperature detection is an artificial spectrum which does not describe reality. The ditch in the spectrum around wave number 667 is an artifact of an ad hoc assumption without connection to reality. It is likely to be scientific fraud, because of lack of connection to reality.

The fraud is rooted in an incorrect conception of two-way heat transfer between two bodies in radiative contact including heat transfer from a cold atmosphere to warm Earth surface named backradiation or downwelling long wave radiation DLR. This comes from a misconception of Planck's radiation law as expressing two-way heat transfer of energy (in W/m2), while the correct Planck's law expresses one-way heat transfer from warmer to colder.

The GHE was invented when in the 1960s thermal detectors reporting radiance were appearing on the market, such as the Kipp and Zonen pyrgeometers measuring temperature and reporting radiance. It can be seen as an illustration of the old fact that if you are going to lie, make it big to make it credible. To give a trace gas a big effect is a big lie.

It is interesting to ponder if Kipp and Zonen can be sued for fabrication radiance spectra without connection to reality. Or is it the chief scientist responsible for the science Kipp and Zonen are referring to, who should be sued? And who is this scientist? What to do if it turns out that this person is dead?

PS The correct Planck law for one-way radiative heat transfer E between two blackbodies 1 and 2 of temperature T_1 and T_2 with T_1 bigger than T_2, is given by
  • E = sigma x (T_1 - T_2) = net transfer of heat energy from 1 to 2
where sigma is a constant. The incorrect Planck law for two-way heat transfer underlying GHE, takes the form
  • E = E_1 - E_2 = net transfer of heat energy from 1 to 2 
  • E_1 = sigma x T_1 = gross transfer of heat energy from 1 to 2
  • E_2 = sigma x T_2 = gross transfer of heat energy from 2 to 1. 
The incorrect Planck law makes it possible to invent gross heat transfer from 1 to 2 by measuring net transfer, combined with an ad hoc assumption about the gross transfer from 2 to 1, which is not measured.

If now GHE is based on an incorrect interpretation of Planck's law, the question is who is to blame? Is it Planck who formulated his law so that misinterpretation is possible? Is it the scientist who first published a misinterpretation Planck's law? If these people are no longer with us, is it a scientist who today repeats the misinterpretation printed in a book, without properly checking that what is printed by a now dead scientist is correct?  Is it a scientist claiming that because it is printed in a book, it can be taken as correct? Is it the scientist responsible for the above radiance spectrum? 

PS2 Searching for the origin of the fiction of recording OLR or downwelling longwave radiation DLR, we are led to Brunt (1932) who proposed the following formula for computing the emissivity epsilon of a cloudless atmosphere:
  • epsilon = a + b x e^0.5,
where e is water vapor pressure and a and b are two parameters determined by calibration. Another formula without parameters was suggested by Brutsaert (1975):
  • epsilon = 1.24 x (e/T)^1/7,
where T is the atmosphere temperature. Many other more or less complicated formulas including parameters to be determined by calibration, have later been suggested. The estimated value of epsilon would then be used to declare that DLR = epsilon x sigma x T^4 according to an incorrect two-way heat transfer Planck formula. All these formulas are nothing but wild guesses to be fitted to measurements of temperature and water vapor pressure, with the objective of delivering estimation of radiance, which cannot be measured directly. They represent fiction or fraud depending on how you view the role of a scientist.

2 kommentarer:

  1. I think you must look further substantial difference between a thermometer and a calorimeter.
    An infrared detector (pyrgeometer, bolometer) is a calorimeter which measures two temperatures (sensor and surrounding sink) that are used to obtain the thermal flux that generates them.
    This tells us thermometry.


  2. See answer to comment by SoD on Fiction of GHE3.