Basic Climate Physics #10

[rebewranger]

Basic Climate Physics #10
13 hours ago Eric Worrall 
The following was reproduced with kind permission from Howard “Cork” Hayden, Prof. Emeritus of Physics, UConn, corkhayden@comcast.net

One fact at a time

This short essay is the tenth in a series about basic (meaning all-inclusive) physics that pertains to the subject of climate.

Bear in mind that my purpose is not to engage in details about wind, rain, snow, storms, historical climatology, Milankovitch cycles, or any of the common topics discussed about climate. What I will discuss is some simple physics.

The Absence of Stefan-Boltzmann

The Stefan-Boltzmann radiation law says that the radiation emitted out through a small hole in a cavity, summed up over the entire spectrum, is equal to

, where T is the Kelvin temperature. The equation has been around since 1884, and put on a solid theoretical foundation by Max Planck in 1900. Curiously, it also applies to solids as diverse as stars, hot pokers, the surface of the earth, including the oceans and the background radiation of the universe. It is the principle upon which non-contact thermometers work.

https://wattsupwiththat.com/category/climate-science/

[Hoodat]

https://wattsupwiththat.com/2022/03/24/basic-climate-physics-10/

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If the greenhouse effect increases, such as by increasing atmospheric CO2 or H2O, then the IR emission to outer space is decreased. That imbalance ( Iout < Iin ) warms the surface until the equality between incoming solar heat and outgoing heat radiation is re-established. (Climate modelers take note: During this time, the warming planet radiates less IR to space than when it was cooler.) In this realistic case, the increase in the greenhouse effect occurs before the temperature increase

I never really thought about it this way before.  If we had an instrument in a vaccuum (e.g. a satellite or on the moon) that measured the heat radiation coming from the sun and earth at the same time, then we could determine from that whether the earth was capturing heat (i.e. warming) or shedding heat (i.e. cooling).  This could be beneficial since the sun's radiation is not constant, and when measured through earth's atmosphere is not a true reflection of that radiation.