Discussion > Its the Gas Laws what dunnit!
In N&Z's reply to questions they state that rotation of an airless planet does not affect mean temperature....Disputed by some at BH.....
"In a recent analytical study, Smith (2008) argued that Eq. (5) only describes the mean temperature
of a non-rotating planet and that, if axial rotation and thermal capacity of the surface are explicitly
accounted for, the average temperature of an airless planet would approach the effective emission
temperature
. It is beyond the scope of the current article to mathematically prove the fallacy of
this argument. However, we will point out that increasing the mean equilibrium temperature of a
physical body always requires a net input of extra energy. Adding axial rotation to a stationary
planet residing in a vacuum, where there is no friction with the external environment does not
provide any additional heat energy to the planet surface. Faster rotation and/or higher thermal
inertia of the ground would only facilitate a more efficient spatial distribution of the absorbed solar
energy, thus increasing the uniformity of the resulting temperature field across the planet surface,
but could not affect the average surface temperature. Hence, Eq. (6) correctly describes (within the
assumption of albedo uniformity) the global mean temperature of any airless planet, be it rotating
or non-rotating."
The full document can be found at the following address.....
http://tallbloke.files.wordpress.com/2012/01/utc_blog_reply_part-1.pdf
RKS
"Adding axial rotation to a stationary
planet residing in a vacuum, where there is no friction with the external environment does not
provide any additional heat energy to the planet surface. Faster rotation and/or higher thermal
inertia of the ground would only facilitate a more efficient spatial distribution of the absorbed solar
energy, thus increasing the uniformity of the resulting temperature field across the planet surface,
but could not affect the average surface temperature. Hence, Eq. (6) correctly describes (within the
assumption of albedo uniformity) the global mean temperature of any airless planet, be it rotating
or non-rotating."
This is non-physical gibberish. One wonders whether it is intentionally disingenuous or merely through confirmation bias.
rhoda
I am enjoying the continued appeals to authority...but if someone called davidmhoffer says it's good why should I not believe him?
More telling are exchnages like this from WUWT:
Willis Eschenbach says:
January 24, 2012 at 9:09 am
Nick Stokes says:
January 24, 2012 at 3:23 am
“that still leaves four parameters and eight data points”
It’s only six data points. If you look at the table in their original post, they didn’t try to fit the Moon or Mercury.
Story just gets better.
w.
Robert Brown says:
January 24, 2012 at 9:17 am
Willis Eschenbach says:
January 24, 2012 at 9:09 am
Nick Stokes says:
January 24, 2012 at 3:23 am
“that still leaves four parameters and eight data points”
It’s only six data points. If you look at the table in their original post, they didn’t try to fit the Moon or Mercury.
Story just gets better.
w.
And note from my argument (and a bit of actual arithmetic, sigh), one of the two forms fit is “one” for all but two points. So really what they have done is joined two fits — an exponential that is 1 for mars and pressures below but a two-parameter fit of Earth and Venus that is as “miraculously” good as you like — I think I could make it 100% accurate with algebra and a hand calculator, but that’s just me, trying to fit an arbitrary two parameter monotonic function that can be made to cut off arbitrarily sharply for pressures below a cutoff with two data points, or I could let a routine split the 2% maximum error up among Mars, Venus and Earth.
The three moons — all with very similar insolation and atmospheric pressures — and Mars are then fit with the two remaining parameters (the ones where 54 Kbar is the characteristic pressure). And look at the exponent! 0.065! It can transform even a tiny number into a big one! Talk about sensitivity…
rgb
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or:
Willis Eschenbach says:
January 25, 2012 at 1:11 pm
Nick Stokes says:
January 25, 2012 at 4:09 am
One of the mysteries of this paper is where the observed T_s values (which they claim to predict) came from. For most, no information on sources is given at all. Europa? Triton? What did they use and how did they get a global figure?
Indeed, that has been asked before and not answered as far as I know. Nor do I know at what level one measures “surface pressure” on a planet with no ocean.
w.
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or:
Nick Stokes says:
January 23, 2012 at 4:11 pm
I agree. They actually fit their multi-parameter formula to only six planet bodies; two are said to have too little atmosphere. But one of those fitted is Europa. As they found in Wikipedia, it has a notional pressure of 10^-7 Pa. About a tenth of a milligram oxygen per sq m, estimated by spectrum. That is the whole “atmosphere”. And this, they claim, enables them to predict the “climate” to 3 figure accuracy using their miracle formula. Despite the fact that pressure has barely one significant figure accuracy, and the measure of “climate” little better.
...
That last quote is a side-splitter. Ideal gases....so I guess you are busy telling me what the temperature will be if the pressure is 1033 bars, rather than 1031 bars...and you can explain how temperature changes over a day without any noticeable change in pressure...because the unmeasured volume and mass of gas has changed somehow. As a hypothesis, it does not even stand up to any level of scrutiny.
diogenes
RKS,
Are you describing an open system or a closed system?
michael hart
sadly RKS lost interest
diogenes
Unlike some poor sods who seem to live their whole lives through the pages of the BH blog, I do have a normal private life to attend to so post as and when I can spare the time. As for the post quoted below - If the author had taken the trouble to read N&Z's paper he would know that they are discussing long term mean global atmospheric temperatures as opposed to the local weather events he refers to, although I think a pressure of around 14,980 psi the supposedly scientifically literate Diogenes refers to is not really relevant to a discussion of the atmosphere. As for Michael Hart's question, I suggest he reads N&Z's theory to answer his questions. I have provided links elsewhere......
"That last quote is a side-splitter. Ideal gases....so I guess you are busy telling me what the temperature will be if the pressure is 1033 bars, rather than 1031 bars...
Jul 7, 2013 at 6:32 PM | diogenes"
RKS
"As for Michael Hart's question, I suggest he reads N&Z's theory to answer his questions. I have provided links elsewhere......"
Jul 12, 2013 at 7:32 PM | Registered CommenterRKS
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I was actually trying to explore your understanding of the matter. A "yes", "no", or even "maybe" would have been a start.
michael hart
I detect bluster. and I never claimed any scientific expertise. But I know Boyle's law and Charles's law and can google the ideal gas laws. So I look at plots from weather stations that show stable pressures but fluctuating temperatures and ask for an explanation in the terms of this miraculous all-explaining paper...and those explanations need to be read by me rather than explained to me.
By now it is bullshit to the power 2. And the increase in bluster from the magus RKS probably adds another 2 levels of power.
diogenes
I think there's enough information in the thread by now to acquaint the casual reader, which is who the thread is aimed at, with the basics of Nikolov and Zellers 'Unified Theory of Climate, and enough to show there are plenty of positive comments as well as the negative ones referred to by some. As I stated earlier, there are plenty of references and related threads on the Tallblokes Talkshop blog.