- CGR 4 has been designed for scientific measurements outdoors of downward atmospheric long-wave radiation with extremely high reliability and accuracy.
- CGR 4 provides an output voltage that is proportional to the net radiation in the far infrared (FIR). By calculation, downward atmospheric long-wave radiation is derived. CGR 4 has an integrated temperature sensor to measure the housing temperature.
The basic idea is that GHE results from "atmospheric re-emission" by in particular CO2 as a "greenhouse gas", the effect of which is seen in as a warming from DLR of about 4 W/srm2 per micrometer at a wavelength of 15 micrometer where the trace gas CO2 is emitting/absorbing.
Kipp&Zonen describes the functioning of its best seller CGR 4 Pyrgeometer as follows
We read that DLR = L_d is computed from Formula 2, where
- U_emf is detector output as a voltage
- 5.67 x 10^-8 x T_a^4 is Stefan-Boltzmann's law for irradiance into a surrounding of 0 K.
- T_b is recorded detector temperature
- S is a sensitivity factor determined by calibration.
- Gross Detector Input = DLR = Net Detector Absorption + Gross Detector Output
- Gross Detector Output = 5.67 x 10^-8 x T_a^4. (False Stefan-Boltzmann Law)
Evidently, Kipp&Zonen can be sued for using a False Stefan-Bolzmann Law, in a case that cannot be lost...
PS The crucial Formula 2 is taken from Guide to Meteorological Instruments and Methods of Observation issued by the World Meteorological Organization (section 7.4.3 formula (7.17)). No scientific reference to (7.17) is given by WMO. So Kipp&Zonen uses a formula issued by WMO without scientific support. Who is then responsible? I think this is an interesting case concerning the responsibility of scientists and scientific institutions, and commercial actors relying on the science. It is clear that in medicine or building technology, there are those who are held responsible. It must be so also in atmospherics science. I will ask WMO for the scientific source and report the answer.
PS2 WMO states on section 7.4.3: Over the last decade, significant advances have been made in the measurement of terrestrial radiation by pyrgeometers, which block out solar radiation. Nevertheless, the measurement of terrestrial radiation is still more difficult and less understood than the measurement of solar irradiance.
Can WMO be sued for distributing science which is admittedly not understood?
PS3 Note the circular argumentation being used: WMO can verify the validity of a formula claimed to be valid by WMO, even if it is not understood, by referring to measurements made by a Kipp&Zonen pyrgeometer constructed from the formula. Any formula can be validated this way.