Written by Christos I. Vournas,
M.sc. mechanical engineer
We do planets and moons surface temperatures comparison.
The presence of atmosphere doesn't warm Earth's surface.
It is the other reasons, not the presence of atmosphere, that make Earth warmer than the Moon by +68°C.
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Key words:
Specular Reflection
Φ - Solar Irradiation Accepting Factor (spherical shape and surface roughness coefficient), for smooth bodies Φ = 0,47 and for rough / porous Φ = 1
Immediate IR Emission
Rotational Warming Phenomenon ( N*cp )1/16
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Φ - Planet surface Solar irradiation accepting factor.
Mathematician Pierre-Simon Laplace once said, "The more shocking an event is, the stronger evidence it needs."
The American cosmologist, Carl Sagan, famously restated it as follows: "Extraordinary claims require irrefutable evidence."
Let's work on Φ -factor hard. It is very important!
1. I did not calculated it. I took it from the table of Data:
The number 0,47 for smooth surface in a parallel fluid flow is taken from the well measured and long ago known Drag Coefficient Data, where Cd =0,47 is for sphere.
It is the portion of incident on sphere energy which should be resisted by sphere to remain in balance.
2. I checked it on the planets without-atmosphere Mercury, Moon, Mars and also (for comparison reasons) on Earth. (Φ =0,47)
Then I continued with other without-atmosphere planets and moons.
Io
"With over 400 active volcanoes, Io is the most geologically active object in the Solar System."
(For Io Φ=1)
Europa
"Europa has the smoothest surface of any known solid object in the Solar System. The apparent youth and smoothness of the surface have led to the hypothesis that a water ocean exists beneath the surface, which could conceivably harbor extraterrestrial life."
(For Europa Φ=0,47)
Ganymede
"Its surface is composed of two main types of terrain. Dark regions, saturated with impact craters and dated to four billion years ago, cover about a third of it. Lighter regions, crosscut by extensive grooves and ridges and only slightly less ancient, cover the remainder. The cause of the light terrain's disrupted geology is not fully known, but was likely the result of tectonic activity due to tidal heating."
(For Ganymede Φ =0,47)
Calisto
"The surface of Callisto is the oldest and most heavily cratered in the Solar System.[16] Its surface is completely covered with impact craters."
(For Calisto Φ =1)
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But has a coefficient from fluid dynamics a relevance to radiative physics?
There are universal laws describing for the matter interacting with energy flow.
I considered a parallel fluid flow as an analogue to the parallel solar rays...
It is the energy interaction with matter. The laws of reflection...
We can observe it in sports, football, basketball etc.
A bullet ricocheting from a target is also an analogue of reflection. The new trajectory is angular incidence on the target dependent direction.
Thus, we are fully convinsed - there is a very important relevance between the coefficient from fluid dynamics and the radiative physics the Φ - Planet surface Solar irradiation accepting factor (the planet spherical shape and planet surface roughness coefficient).
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Io and Europa
Io and Europa is an example of the planet or moon surface temperatures comparison:
Io and Europa are at the same distance from the sun. Both have the same satellite measured Albedo.
Io (Jupiter's satellite), Albedo a =0,63
Flux _ 50,37 ( W/m² ) Te = 95,16 K
Te.correct = 95,16 K, Φ = 1
Warming Factor (β*N*cp)¹∕ ⁴ = 1,8647
Tsat = 110 K
Europa (Jupiter's satellite), Albedo a =0,63
Flux _ 50,37 ( W/m² ) Te = 95,16 K
Te.correct = 78,83 K, Φ = 0,47
Warming Factor (β*N*cp)¹∕ ⁴ = 2,5494
Tsat = 102 K
110K /102K = 1,0784
[ (1*1,8647 ) /(0,47*2,5494) ]¹∕ ⁴ = 1,1169
1,1169 /1,0784 = 1,0357 or 3,57 %
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Table of contents - Links
0). Explain Rotational Warming Model.
Demonstrate the Initial PREMISE, Links: (1) and (2)
3).The Planetary Temperatures Comparison Criteria.
4). "The total amount of the specularly reflected portion of solar flux"
5). How A Planet Retains The Solar Energy - the role of the Immediate IR emission.
6). Φ -Factor is an analogue of the well known Drag Coefficient Cd=0,47
7). “What ‘portion’ of ‘sunlight’ reaches surface of Earth?”
8). The satellites do not measure Bond Albedo.
9). Stefan-Boltzmann formula J = σ T4 W/m² doesn't apply to terrestrial temperatures.
10). The Theoretical Equation.
12). The actual reason of the observed Global Warming.
13). The Axial Precession's role in Global Warming.
14). The Original Milankovitch cycle.
15). The Reversed Milankovitch cycle.
16). The higher CO2 content in ice core samples relates to colder periods.
17). Sensible Heat /Latent Heat ratio.
18). The conventional greenhouses, and the role of immediate IR emission.
19). NASA Technical Memorandum An Earth Albedo Model
20). The yearly total Immediate IR Emitted solar energy - in our times - is lower.
21). The yearly total reflected solar energy - in our times - is lower.
Appendix - Links
1). Earth's Corrected Effective Temperature (210 K ) calculation.
2). Earth's Average Surface Temperature (288 K ) calculation.
3). Moon's Corrected Effective Temperature (224 K ) calculation.
4). Moon's Average Surface Temperature (220 K ) calculation.
5). Mars' Corrected Effective Temperature (174 K ) calculation.
6). Mars' Average Surface Temperature (210 K ) calculation.
7). Mercury's Corrected Effective Temperature (364 K ) calculation.
8). Mercury's Average Surface Temperature (340 K ) calculation.
9). Titan's Average Surface Temperature (93,7 K ) calculation.
10). Earth / Mars satellite measured mean surface temperatures 288 K and 210 K comparison.
11). Earth's /Moon's temps 288K /220K comparison.
13). Blog.
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The table of contents will be completed some time soon. For more pages view the menu at the top.
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