Effect of thickness of atmosphere on the incident light on land

Click For Summary

Discussion Overview

The discussion centers on the hypothetical effects of a thicker atmosphere on the appearance of snow, particularly focusing on how changes in atmospheric thickness might alter the spectrum of incident light and the perceived color of snow. The scope includes theoretical considerations of light scattering and absorption, as well as implications for color perception.

Discussion Character

  • Exploratory
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that a thicker atmosphere would cause snow to appear red due to increased scattering of blue light, leading to predominantly red light being reflected off the snow.
  • Another participant acknowledges that while scattering is a factor, the absorption characteristics of different frequencies of light would also significantly affect the spectrum of light reaching the ground.
  • A request for further detail on the effects of absorption and scattering indicates a desire for deeper exploration of the topic.
  • A later reply references a link to a solar spectrum image, noting that atmospheric absorption modifies the light spectrum and that these effects would become more pronounced with a thicker atmosphere, particularly at non-optical frequencies.
  • Concerns are raised about the impact of denser atmospheric molecules on light absorption, suggesting that this could lead to more noticeable color changes in the light reaching the surface.
  • There is a mention of human color perception, proposing that people might adapt to changes in light conditions under a thicker atmosphere, similar to how they perceive colors under different artificial lighting.

Areas of Agreement / Disagreement

Participants express differing views on the primary factors affecting the color of snow under a thicker atmosphere, including the roles of scattering and absorption. The discussion remains unresolved, with no consensus on the specific outcomes of these effects.

Contextual Notes

Limitations include assumptions about the uniformity of atmospheric composition and the complexity of light interactions with various atmospheric components. The discussion does not resolve the mathematical or physical details of these interactions.

Pranav Jha
Messages
141
Reaction score
1
How would the whiteness of snow appear if Earth's atmosphere were several times thicker?

I think it would appear red as most of the blue frequency light would be scattered before reaching the Earth and the majority of light being reflected of the snow would be red.

Am i right?
 
Science news on Phys.org
Whilst this must be an effect, I think the difference in absorption at the different frequencies, as well as the scattering, would have an effect in the spectrum of the light reaching the ground.
 
sophiecentaur said:
Whilst this must be an effect, I think the difference in absorption at the different frequencies, as well as the scattering, would have an effect in the spectrum of the light reaching the ground.

Could you please be more detailed about the effects you were referring to in the above answer?
 
http://en.wikipedia.org/wiki/File:Solar_Spectrum.png"
If you look at this link it shows that atmospheric absorption modifies the spectrum (in the fine detail) of the incident Sunlight in addition to the effect of Raleigh scattering (the general trend). Absorption effects are more marked at non-optical frequencies, of course, with huge amounts of absorption of microwave frequencies by water vapour. Both effects on the optical bands would get more and more pronounced as the atmosphere gets thicker and thicker.
I have a feeling that, in a thicker atmosphere, the effects of absorption by some of the more dense but more rare molecules (which collect more in the bottom layers) would be more marked than at the present atmospheric thickness and pressure. This would produce proportionally more noticeable colouring.

I assume you are taking snow to be a good reflector of light at all wavelengths, producing what we would call 'white' with the Sun overhead. Our (brain) colour compensation circuits do a lot better than those in cameras and I have a feeling that we would very soon accept a modified version of this if we were to spend much time under a more dense atmosphere, in much the same way as we 'see' white things as white under tungsten and flourescent lights.
 
Last edited by a moderator:

Similar threads

  • · Replies 40 ·
2
Replies
40
Views
5K
  • · Replies 4 ·
Replies
4
Views
12K
  • · Replies 4 ·
Replies
4
Views
8K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 7 ·
Replies
7
Views
5K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
23
Views
8K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 5 ·
Replies
5
Views
3K