Understanding OLR and DLR vs Radiance Measurement by CERES and Pyrgeometer.

Outgoing Longwave Radiation OLR from the Top of the Atmosphere ToA is measured by a CERES satellite looking down on ToA equipped with a sensor as one end of a thermocouple with its other end kept at a steady temperature generating a voltage scaling with the temperature difference at its ends. 

The CERES instrument is calibrated by determining a gain factor from sensor temperature to radiance letting the instrument look at a black body of known temperature $T_B$ with assumed Planck radiation $\sigma T_B^4$ while recording the sensor temperature. With the gain factor so determined the instrument reports radiance from ToA from a reading of sensor temperature. This is the simplest form of calibration assuming linearity. Very primitive technique, where the details of the instrument do not matter. It is like measuring intensity of rainfall using your hands to collect water calibrated to a faucet. The accuracy is at best 1 W/m2 or 0.4% of the same size as estimated Earth Energy Imbalance from CO2.  

A pyrgeometer measuring Downwelling Longwave Radiation from the atmosphere to the Earth surface also uses a sensor as one end of a thermocouple with the other end kept a base temperature, and also measures a voltage scaling with temperature difference. The calibration is here different because the outgoing radiation from the sensor can no longer be included in the calibration process, but has to be supplied through a Planck formula $\epsilon\sigma T^4$ with $T$ sensor temperature and $\epsilon$ sensor emissivity. The accuracy is at best 5 W/m2 again too big to detect global warming if present.

OLR and DLR are thus measured in a similar way, but with different forms of calibration the difference being that OLR faces empty space ay 0 K, while DLR faces the Earth surface. The accuracy is not enough to decide any size of global warming, although it is claimed that trends can be detected. 

In both cases Planck's Law in the form $\sigma T^4$ is used, which in the case of DLR is incorrect because the correct form is $\sigma (T^4-T_E^4)$ with $T_E$ Earth temperature expressing negative DLR.  

Summary: Measurements of OLR and DLR are made to detect global warming. The accuracy of the instruments is not good enough to detect any warming if present. DLR measurements can be questioned since an incorrect Planck Law is used. OLR and DLR as radiance as process variable fluctuate and as such are difficult to measure.  

EEI is a cornerstone of global warming alarmism, and so measuremennt of EEI has become a prime task for instrument technology, which does not seem to have delivered. The effect of EEI on surface temperature is unknown and impossible to measure and DLR is a misconception based on an incorrect form of Planck's Law.

ChatGPT on objective of CERES: 

CERES connects to global warming because it:

• Measures the planetary energy balance directly at TOA.

• Detects changes in OLR and OSR (reflected shortwave) caused by greenhouse gases, aerosols, clouds, and ice.

• Provides the evidence that Earth is currently taking in more energy than it loses — the physical basis of global warming.

ChatGPT on objective of measuring DLR :

• Provide a direct measure of the atmosphere’s infrared emission to the surface, essential for closing the surface energy budget, quantifying the greenhouse effect, tracking climate change, and validating models.

We read that the objective of CERES is to support global warming alarmism by measuring and reporting EEI attributed to CO2. But the objective is not reached, because (i) the accuracy of the measurement is not better than 1 W/m2, which is the expected size of EEI, and (ii) attribution to CO2 to is not credible because it is swamped by changes of cloud cover. We read that the objective of measuring DLR by a pyrgeometer is to quantify greenhouse effect. Both cases amounts to "chasing after wind" using "ghost detectors". 

Buying a Tesla vs Pyrgeometer Realities

If you feel depressed, here are two nice ways to get happy again: Buy a Tesla or a Pyrgeometer. You know what a Tesla is and what a pyrgeometer is can be read by downloading the manual for the Kipp and Zonen CGR3 Pyrgeometer. It shows that a pyrgeometer, when directed to the sky, on its display shows Downwelling Long Wave Radiation DLWR (also named back radiation) from a colder atmosphere to a warmer Earth surface of typically size 340 W/m2 to be compared with the 170 W/m2 absorbed by the surface from the Sun, about two extra Suns. 

If you are a CO2 alarmist this makes you really happy because you can now point to these two extra Suns as a supposed massive effect from so called atmospheric greenhouse gasses supposed to radiate massive DWLR. 

Now, the manual shows that the thermopile of the pyrgeometer measures a voltage scaling with the difference of atmospheric and Earth surface temperature of typically 15 C with estimated net radiative flux of 60 W/m2 from the surface to the atmosphere. That is what is measured, which is not so fun to look at for an alarmist, so to make such people happy Kipp and Zonen instead displays 340 W/m2 from the atmosphere to the surface computed from the following equation

• 400 = 340 + 60, 

where 400 is by Planck postulated Outgoing Long Wave Radiation OLWR from the pyrgeometer at 15 C, as if the pyrgeometer as a blackbody is in radiative contact with the cold outer space at 0 Kelvin.  Further, 340 is DWLR and 60 as above radiation from surface to atmosphere. So we get 340 = 400 - 60 as DWLR. But doing so the pyrgeometer acts as a ghost detector by assuming massive OLWR from the pyrgeometer as if it is in radiative contact with cold outer space at 0 C, while in fact it is radiative contact with a 15 C colder  atmosphere. What is measured is 60 up, but what is reported is 340 down. 

This is nothing but scientific fraud created by a misrepresentation of a key physical fact: The pyrgeometer is not in radiative contact with outer space at 0 K, but with a 15 C colder atmosphere (the atmospheric window is small). This is massive fraud serving as the instrumental basis for Net Zero, which if implemented would throw humanity back to the Stone Edge at greatly reduced numbers. Can you think of something bigger?

When you realise this you will get depressed again, but then after a second thought you can restore happiness by recalling that you have revealed/understood the scientific fraud of global warming, and then you can proceed to a happy life without worrying about CO2 emissions and Net Zero. Happy, right?

To compare with the Tesla, suppose your Government offers you a massive repay/refund as Downwelling Government Money DGM of 70.000 dollars if you purchase a new Tesla for 80.000 and thus only have to pay net 10.000 according to the formula:

• 80 = 70 + 10.

You would then get happy, right? But you may quickly get a second thought and ask who will pay the DGM? From where can this money come? Could it be that it will come from taxes you pay, so that in fact you have to pay the full amount 80.000, which is way beyond your budget. Ok, so this will make you depressed. But again, when you realise that there is no need for any Tesla at all if there is no Net Zero, and so you are not pressed to buy a Tesla to save the World. Happy, right?

If you don't think that what I say above is true, take a look at the following Earth's Energy Budget presented by NASA:

Compare now with the Wikipedia energy budget without Back Radiation DWLR:

We thus meet two versions of Earth's energy budget underlying CO2 alarmism, one with and one without Back Radiation. This connects to Bohr's idea of complementarity: Light is both particles (photons) and waves, which are viewed not as contradictory but simply as complementary views of a richer particle-wave phenomenon. In fact, any contradiction in physics can be handled this way, in particular Earth's energy budget, which in a fundamental way is based on Back Radiation (top picture), while at the same time it has nothing to do with any such concept (below picture). Back Radiation is truly fundamental, yet you can do without it completely. It exists and does not exist, and that is no contradiction, only complementary views. This is modern physics at its best. 

If you have in your hands both A and notA as being true, then you can win any discussion. Whatever your opponent say, A or notA, you can say that he/she is wrong and that you are right. Very clever strategy.

Try it to see how smoothly it works!

 

Discussion with Will Happer on Temperature vs Radiation Measurement

The discussion with Will Happer recorded in the previous post concerns the question what pyrgeometers and bolometers primarily measure: (a) temperature or (b) radiative heat energy flux. Will says (b) and I say (a). 

My argument is that if you look into the design of pyrgeometer, you see that it uses a thermopile, which is a device which reports a voltage which scales with the temperature difference between the two ends of the thermopile with one end by radiative equilibrium taking the same temperature as a distant source and the other end in contact with an ordinary thermometer which can be read. After calibration you can then from measured voltage and temperature read determine the temperature of the distant source. A pyrgeometer thus acts a thermometer which can read temperature at distance. This is what an infrared camera does.

A bolometer works in a similar way using a sensor with resistance scaling with temperature difference vs a thermal reservoir at constant known temperature.   

Will has another conception of pyrgeometers and bolometers:

1. Spectral intensity measurements are often expressed as equivalent temperatures. 
2. But the basic measurement is of energy fluxes which produce voltages or currents in sensor elements.

Will thus claims that the basic measurement is radiative energy flux and not temperatures. How can this be? 

Here 1 gives a clue: Will says that in some sense temperature and radiative energy flux are "equivalent". But what is this equivalence? After all, temperature is a state variable depending on the state of a system while radiative energy flux is a process variable depending on the process involved. In any case the standard procedure is to connect radiative flux $Q$ to temperature $T$ by the Planck/Stefan/Boltzmann Law for black/grey body radiation

• $Q=\epsilon\sigma T^4$      (1) 

where $\sigma$ is the Stefan-Boltzmann constant $\epsilon$ emissivity. This gives radiative flux the quality of a state variable, but this runs the risk to be misleading, since the process aspect is forgotten. A correct process version of the PSB Law reads

• $Q=\epsilon\sigma (T^4 - T_b^4)$   (2)

where $T_b$ is a background temperature like the temperature of the thermal reservoir for the bolometer. Only if $T_b=0$ does (1) give a correct connection between temperature and radiative energy flux and in addition the emissivity enters as an unknown to determine. Compare with next post.

The confusion increases by letting the pyrgeometer on its display show Downward Long Wave Radiation which is computed from the measured voltage as shown in PS3 below using (1) to express Outgoing Long Wave radiation from the instrument. A pyrgeometer thus measures temperature but reports radiative energy flux by using (1), which does not involve the process. You can thus be fooled by a pyrgeometer, which may be hard to accept if you just have bought one.   

My conclusion: 

• Pyrgeometers and bolometers do what is physically possible, namely to directly measure the temperature of a source by putting a thermometer in close or distant radiative contact with the source. 
• On the other hand, to measure radiative energy flux is very difficult since a whole process is involved with many unknowns and that is not what pyrgeometers and bolometers can do.
• See presentation at Climate Sense 2018. 

I am waiting for Will's conclusion.

PS1 Read about the Kipp and Zonen CGR3 Pyrgeometer:

• The CGR3 is a pyrgeometer, designed for meteorological measurements of downward atmospheric long wave radiation. 
• The CGR3 provides a voltage that is proportional to the net radiation in the far infrared (FIR). 
• By calculation, downward atmospheric long wave radiation is derived.

It is clearly stated that the pyrgeometer is a ghost detector serving climate alarmism measuring one thing (net temperature difference) and reporting something else (gross downward atmospheric long wave radiation), which is derived by (1). This has become so accepted, that even many skeptics believe in what the instrument display shows, although it defies scientific sense. If you have invested in a Kipp and Zonen CGR3 Pyrgeometer, you may not want to hear that you have bought a ghost detector, unless you want to send a ghost CO2 alarm…

PS2 You may compare measuring the difference between your body temperature and the surrounding room temperature, which is easy to do, with measuring how much your body is radiatively heated by the colder walls of the room, which is impossible without a ghost detector.

PS3 From the Kipp and Zonen Instruction Manual:

We see that the instrument display does not show net recording as the voltage $U_{emf}$ but instead gross $L_d$ as DWLR being computed from Formula 1 with $5.67*10^{-8}*T_b^4=\sigma T_b^4$ the incorrect gross outgoing upwelling ghost radiation from the pyrgeometer as if it was in radiative contact with outer space at 0 Kelvin. By claiming gross upwelling radiation, gross downwelling radiation is concluded, but the upwelling radiation is not real but ghost radiation. 

To well understand (not get fooled by) what an instrument display reports, it is necessary to look into the design of the instrument by reading the manual to see what is effectively measured and what is displayed. This is what I did above.