The solar energy intensity W/m² primarily reaching the planet's surface is what actually determines the planet's surface temperatures.
The solar energy intensity W/m² primarily reaching the planet's surface is what actually determines the planet's surface temperatures.
In other words it is the distance from the sun which makes the solar energy reaching planet weaker.
It is the square inverse law: 1 /R² - where R is the distance from the sun in AU (astronomical units).
What planet's surface is capable to do with the incoming solar energy (how effectively it is capable to hold the incoming energy) also determines the level of the surface temperatures.
One of the energy "holding" planet's surface properties is the atmosphere greenhouse effect.
In Earth's case the greenhouse effect is very weak and cannot be considered as an important Earth's surface warming factor.
Other factors influencing planet's surface temperature are the planet's surface reflection ability and the planet's surface emission /accumulation ratio.
On Planet's surface the energy Emission /Accumulation ratio
The by solar irradiated planet's surface the energy
Emission /Accumulation ratio.
When solar irradiated, planet's surface always has a certain the energy
Emission /Accumulation ratio.
It happens so because those are different mechanism energy transfer processes.
The incoming solar energy is one a pure radiative energy.
When solar irradiation interacting with the planet's surface there are two different physics phenomena take place.
The by the surface instant IR emission and by the surface heat accumulation (conduction).
And it is observed that when the surface's temperature is higher, everything equals, the
Emission /Accumulation ratio is higher.
Consequently when rotating slower and having a lower cp the planet's surface gets hotter and the planet's surface emits more and accumulates less.
And the opposite, It is observed that when the surface's temperature is lower, everything equals, the
Emission /Accumulation ratio is lower.
Consequently when rotating faster and having a higher cp the planet's surface warms less and the planet's surface emits less and accumulates more.
Why? How can it be explained?
It can be explained by the difference in energy transfer by radiation vs energy transfer by conduction.
The energy transfer by radiation is in fourth power of the surface's absolute temperature.
The energy transfer by conduction is linear of the surface's layers temperature gradient.
Example:
Let's have a planet's surface T = 100 K
Jemission = σT⁴ = σ*100⁴ = σ*100.000.000
Jconduction = c*ΔT = c*ΔT
Jemission /Jconduction = σ*100.000.000 /c*ΔT
-
Let's have a planet's surface T = 200 K
Jemission = σT⁴ = σ*1.600.000.000
Jconduction = c*ΔT
Jemission /Jconduction = σ*1.600.000.000 /c*ΔT
-
σ = 5,67*10⁻⁸ W/m²K⁴, the Stefan-Boltzmann constant
c - is the coefficient of conductivity
Thus in this simple example we have illustrated that when a planet's surface gets warmed at higher temperatures, everything equals, the energy
Emission /Accumulation ratio is higher.
The planet's surface accumulates less.
And when a planet's surface gets warmed at lower temperatures, everything equals, the energy
Emission /Accumulation ratio is lower.
The planet's surface accumulates more.
That is why sea accumulates much more heat than land.
That is why, when we have Earth and Moon having the same solar flux of So = 1361 W/m² Moon rotating slower and having a lower cp, at daytime is getting hotter and having a higher the energy
Emission /Accumulation ratio.
So Moon's surface accumulates less.
Earth rotating faster and having a higher cp, at daytime getting less warm and having a lower the energy
Emission /Accumulation ratio.
So Earth's surface accumulates more.
The planet's faster rotation benefits in favor of surface accumulation process
From my previous note:
the energy Emission /Accumulation ratio
"Earth rotating faster and having a higher cp, at daytime getting less warm and having a lower the energy Emission /Accumulation ratio. So Earth's surface accumulates more".
The planet's faster rotation benefits in favor of surface accumulation process.
During the long 29,5*24hours /2 = 354 hours of insolation lunar day the Moon's surface gets the same exactly amount solar energy as Earth's surface (which differs only due to the different albedo) gets during these 29,5*24hours /2 = 354 hours of insolation...
The major difference for Earth is that Earth's surface "passes" 29,5 times under the sun and has 29,5 intervalls of non insolating the surface nights.
Earth's surface is given 29,5 times more time to accumulate energy...
The energy emission and accumulation procesess are time dependent actions.
The longer is the accumulation process - the bigger is the amount of accumulated energy.
Earth's and Moon's surfaces are solar irradiated the same exactly hours...
but the Emission /Accumulation ratio is smaller for Earth, so Earth in a unit of time is capable to accumulate more...
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