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Old 8th July 2010, 02:45 PM   #61
Trakar
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Originally Posted by wogoga View Post
Do you have evidence for the non-reflectivity of atmospheres based on more than wishful thinking?

From On observing the compositional variability of the surface of Venus using nightside near-infrared thermal radiation:

A simple radiative transfer model demonstrates that multiple reflection of thermal radiation between the atmosphere (including clouds) and the solid surface has a significant influence on the observed radiance under the condition of Venus, where reflectivity of overlying atmosphere and clouds is high.
I'm sure "cherry-picking" and misrepresentation weren't your intentions, but do you not understand the difference in meaning between the sentence you present and the full context of the abstract from which you extracted it?
Quote:
There are several windows in the near-infrared wavelength range (∼1 μm), in which thermal radiation emitted from the planetary surface penetrates through the thick Venus atmosphere and clouds. In this study we develop an improved method to estimate the surface emissivity on the basis of near-infrared thermal emission from the nightside Venus, which is observed through these windows. A simple radiative transfer model demonstrates that multiple reflection of thermal radiation between the atmosphere (including clouds) and the solid surface has a significant influence on the observed radiance under the condition of Venus, where reflectivity of overlying atmosphere and clouds is high. Thus it is necessary to take the effect of the reflection by the planetary surface into account in order to estimate accurately the variation in the surface emissivity on the basis of near-infrared observation of Venus. The net effect of multiple reflection of surface thermal radiation between the atmosphere and the surface is to significantly reduce the spatial contrast in thermal radiation due to surface compositional variation. The model calculation demonstrates that despite this effect, detection of granitic rocks on the Venus surface using near-infrared windows is feasible. Since granitic and basaltic rocks have dramatically different 1 μm emissivities, granitic rocks are distinguishable from basaltic rocks by ground-based telescopic observation. A Venus orbiter that measures both the near-infrared thermal radiation and the surface altitude with great accuracy will provide us with a reliable surface emissivity map of Venus, which is a very valuable tool to detect granitic (i.e., Earth-like continental) rocks on Venus.
Quote:
From Warming Early Mars with Carbon Dioxide Clouds That Scatter Infrared Radiation:
Model calculations show that the surface of early Mars could have been warmed through a scattering variant of the greenhouse effect, resulting from the ability of the carbon dioxide ice clouds to reflect the outgoing thermal radiation back to the surface.
Exactly what relationship (other than having common search terms like "CO2." "infrared" and "Reflection") do you perceive between "carbon dioxide ice clouds" and anything that has or is being discussed?

Quote:
From Thermal radiation fluxes in the lower atmosphere of Venus:
It is found that with an H2O content of about 0.00001, the fluxes may agree if the clouds reflect more than 60% of the thermal radiation incident on them.
Again, from a 45 year old Russian paper, speculating about issues long since resolved, and discussing the H2O content of the atmosphere and how it may interact with CO2 to alter the IR windows, rather like Lowel's speculations upon how the Martian canals were maintained, and about as relevent to what is being discussed

context and content are much more important than the simplistic term searches you seem given over to.
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