The Thermal Radiation of the Atmosphere and Its Role in the So-Called Greenhouse Effect

Knowledge about thermal radiation of the atmosphere is rich in hypotheses and theories but poor in empiric evidence. Thereby, the Stefan-Boltzmann relation is of central importance in atmosphere physics, and holds the status of a natural law. However, its empirical foundation is little, tracing back to experiments made by Dulong and Petit two hundred years ago. Originated by Stefan at the end of the 19 century, and theoretically founded afterwards by Boltzmann, it delivers the absolute temperature of a blackbody—or rather of a solid opaque body (SOB)—as a result of the incident solar radiation intensity, the emitted thermal radiation of this body, and the counter-radiation of the atmosphere. Thereby, a similar character of the blackbody radiation—describable by the expression σ·T—and the atmospheric counter-radiation was assumed. But this appears quite abstruse and must be questioned, not least since no pressure-dependency is provided. Thanks to the author’s recently published work—proposing novel measuring methods—, the possibility was opened-up not only to find an alternative approach for the counter-radiation of the atmosphere, but also to verify it by measurements. This approach was ensued from the observation that the IR-radiative emission of gases is proportional to the pressure and to the square root of the absolute temperature, which could be bolstered by applying the kinetic gas theory. The here presented verification of the modified counter-radiation term A·p·T in the Stefan-Boltzmann relation was feasible using a direct caloric method for determining the solar absorption coefficients of coloured aluminium-plates and the respective limiting temperatures under direct solar irradiation. For studying the pressure dependency, the experiments were carried out at locations with different altitudes. For the so-called atmospheric emission constant A an approximate value of 22 Wm bar K was found. In the non-steady-state, the total thermal emission power of the soil is given by the difference between its blackbody radiation and the counter-radiation of the atmosphere. This relation explains to a considerable part the fact that on mountains the atmosHow to cite this paper: Allmendinger, T. (2018) The Thermal Radiation of the Atmosphere and Its Role in the So-Called Greenhouse Effect. Atmospheric and Climate Sciences, 8, 212-234. https://doi.org/10.4236/acs.2018.82014 Received: March 5, 2018 Accepted: April 23, 2018 Published: April 26, 2018 Copyright © 2018 by author and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY 4.0). http://creativecommons.org/licenses/by/4.0/


Introduction
The topics of contemporary publications about climate usually deal with delivering further evidence for climate warming and its impacts on the one hand, and with the objective of how the results of climate science can be transformed into political actions on the other hand. Besides, they are always based on the assumption that these results are correct. However -as my own research has yielded -, this is not at all the case. The respective argumentation is not only based on theoretical objections, but also -and not least -on measurements applying novel detection methods. In particular, the key assumption of the predominant greenhouse theory, that carbon-dioxide (or further «greenhouse gases») is responsible for global warming, turned out to be completely wrong. Instead, the so-called albedo of the Earth's surface represents the governing factor which can be influenced by artificial measures. This albedo indicates the portion of the solar light which is reflected on the Earth's surface into the atmosphere and finally into space. The not-reflected solar light is absorbed by the Earth surface leading to a temperature rise which is transported to the lowest layer of the atmosphere. But the conventional greenhouse theory disregards this heat transfer at the boundary, instead of considering the absorption of the thermal Earth's radiation by the whole atmosphere, and assuming that only «greenhouse gases» can act as absorbers. Moreover, it disregards the counter-radiation of the atmosphere onto the Earth's surface. For investigating such problems, the central question has to be answered: How and to which extent infrared radiation energy is transformed into heat energy of gases, and vice versa? This question has never been asked so far; but it could be answered by using the proposed methods.

Presumptions of the CGT:
• The atmosphere is solely warmed up by the thermal blackbody-radiation of the Earth surface, which is warmed up by incident solar radiation • This atmospheric warming-up is solely due to «greenhouse gases» such as CO 2 • For the surface temperature of the Earth, a global average value of 288 K = 15°C is assumed • The incident solar radiation is not absorbed by the atmosphere, at least not in the IR-range Objections against the CGT: • Not the whole atmosphere is primarily relevant for climate, but solely its lowest layer • Besides the thermal radiation of the Earth's surface, an additional heat transfer soil-air occurs • The intensity loss of the incident solar light passing through the atmosphere lets suppose an absorption • CO 2 cannot be relevant for climate warming due to its very low concentration in the air (0.04 %) • It is not permissible to operate with a global average • When the limiting temperature is reached, the radiative emission intensity is identically equal to the radiative absorption degree • Hypothesis: The emission intensity is proportional to the collision frequency of the molecules • Applying the kinetic gas theory, the comparison of the noble gases argon, neon and helium yields the dependence on the atomic cross sectional area, the pressure and the root of the absolute temperature  • Consequence: When a coloured solid opaque body (SOB) is irradiated by solar light, and when a steady radiation equilibrium is reached, the absorbed part of the solar light must be equal to the difference between the black-body-radiation of the SOB and the counter radiation of the atmosphere: Φ solar x β solar = σ x T SOB,eq 4 -Φ atm β solar = solar absorption coeff. = 1 -α solar (solar reflection coeff.) Thomas Allmendinger: The Thermal Radiation of the Atmosphere (15)

Measurement of the Solar Absorption Coefficient β s
• Customary method: measuring the solar reflection coefficient (or albedo) α s , defined as the quotient reflected/incident light-intensity, e.g. with an albedometer (left pic), yielding β s = 1-α s • Inaccuracies due to light dispersion (right pic) • Preferred direct determination of β s by temperature measurements at irradiated aluminium-plates (own novel method, cf. page 17)

How can the atmospheric radiation constant A empirically be determined?
• When a plate of a solid opaque body is irradiated by sunlight, it is warmed up to a limiting temperature, depending on the surface colour of the plate. When this temperature is determined, together with the atmospheric pressure and the ambient atmospheric temperature, and when the solar intensity is known (measured with an electronic «solarmeter»), A can be easily computed • The value of A can be verified (a) by using differently coloured plates and (b) by varying the atmospheric pressure, using locations with different sea levels (lowland -mountain)

Conclusions and Consequences
• The counter-radiation of the atmosphere is directly proportional to the atmospheric pressure at the boundary of the Earth's surface • A reduction of the counter-radiation leads to an intensified cooling-down of the Earth's surface since the relative portion of its thermal emission increases • Carbon-dioxide or other so-called Greenhouse Gases do not have any influence on the climate • The only feasibility of mitigating the climate consists