The solar energy intensity W/m² primarily reaching the planet's surface is what actually determines the planet's surface temperatures
The distance a planet orbits sun determines the solar flux’ intensity incident on it.
For Earth it is So = 1361 W/m²
For Moon it is So = 1361 W/m²
And For Mars it is S = 585,4 W/m²
– We consider solar flux on the Earth’s TOA (top of atmosphere) as
So = 1361 W/m²
Because not the entire solar radiative energy reaches Earth’s surface.
– Earth’s Albedo is on average a=0,306 because of the clouds which reflect stronger than surface, so the combined diffuselly reflected energy is on average
Jdiffuse = 0,306*So W/m².
– Thus only the (1-a)So = 0,694So = 0,694*1361 W/m² = 944,5 W/m² on average reaches a flat plate on Earth’s surface perpendicular oriented to the solar rays.
– Earth’s TOA is where we can measure the exact solar flux at the Earth’s distance from the Sun.
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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.
Yes, but 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.
Table 1. Comparison of Predicted vs. Measured Temperature for All Planets
Table 1. Comparison of Predicted vs. Measured Temperature for All Planets
Distance Flux Factor Bond rot /day surface cal /gr. oC °K °K °K °K
( AU ) ( W/m² ) Φ Albedo N Spin Type Cp (β*N*cp)¹∕ ⁴ Te Te.correct Tsv Tsat
Mercury 0,387 9082,7 0,47 0,068 0,00568 basalt 0,20 0,64250 439,6 364,0 325,83 340
Venus 0,723 2601,3 1 0,77 60/243 gases 0,19 1,6287 226,6 255,98 - 737
Earth 1,0 1361 0,47 0,306 1,0 ocean 1 3,4996 254 210 287,74 288
Moon 1,0 1361 0,47 0,11 0,0339 regolith 0,19 0,99141 270,04 224 223,35 220
Mars 1,524 586,4 0,47 0,25 0,9728 rock 0,18 2,26495 209,8 174 213,11 210
Ceres 2,77 177,38 1 0,09 2,645 rock 1 4,463 162,9 162,9 236 -
Jupiter 5,20 50,37 1 0,503 2,417 gases - - 102 102 - 165 at 1 bar level
Io 5,20 50,37 1 0,63 0,5559 rock 0,145 1,8647 95,16 95,16 111,55 110
Europa 5,20 50,37 0,47 0,63 0,2816 rock 1 2,5494 95,16 78,83 99,56 102
Ganymede 5,20 50,37 0,47 0,41 0,1398 rock 1 2,14 107,08 88,59 107,14 110
Calisto 5,20 50,37 1 0,22 0,0599 rock 1 1,7313 114,66 114,66 131,52 134±11
Saturn 9,58 14,84 1 0,342 2,273 gases - - 81 81 - 134 at 1 bar level
Enceladus 9,58 14,84 1 0,85 0,7299 rock 1 3,2347 55,97 55,97 75,06 75
Tethys 9,58 14,84 1 0,70 0,52971 rock 1 2,9856 66,55 66,55 87,48 86 ± 1
Titan 9,58 14,84 1 0,22 0,06289 gases 0,4980 1,47223 84,52 84,52 93,10 93,7
Uranus 19,22 3,687 1 0,30 1,389 gases - - 58 MM * - - 76 at 1 bar level
Neptune 30,33 1,48 1 0,29 1,493 gases - - 46,4 46,4 - 72 at 1 bar level
Triton 30,33 1,48 0,47 (?) 0,76 0,17021 rock 0,4116 1,800 35,4 29,29 33,92 38
2) Triton 30,33 1,48 1 (?) 0,76 0,17021 rock 0,4116 1,800 35,4 35,4 40,97 38
Pluto 39,48 0,874 1 0,50 0,1565 rock 0,248 1,5533 37 37 41,6 44
Charon 39,48 0,874 1 0,2 0,1565 rock 1 2,2014 41,90 41,90 51,04 53