UPDATE2: The question has been resolved, please see this new WUWT story on the issue. – Anthony
UPDATE: There is a debate raging in comments about the validity of the statement “That is four degrees below the freezing point of CO2 and would cause dry (CO2) ice to freeze directly out of the air.”
On one hand we have an argument from several commenters that says that the temperatures, pressures, and phase diagrams only apply to a pure state of CO2, such as in the manufacture of dry ice.
“Certainly, at least some of the CO2 in the atmosphere at the poles does freeze out (of the air) during the winter.”
So there appears to be a debate. If it turns out the statement is wrong, and some empirical proof can be presented, I’ll retract and/or amend the article. There appears to be a wide interest in this question, so I’m not opposed to find the true answer, even if it means the statement is entirely wrong.
Feel free to post in comments, but leave the snark and ad hom out of it. I’m more interested in settling the question.
I’ve also changed the title to be more reflective of the question before us now. – Anthony
By Steven Goddard
The south pole of Mars (seen below) similarly has an eight metre thick layer of dry (CO2) ice on top of the H2O ice.
Mars, too, appears to be enjoying more mild and balmy temperatures. In 2005 data from NASA’s Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide “ice caps” near Mars’s south pole had been diminishing for three summers in a row. Habibullo Abdussamatov, head of space research at St. Petersburg’s Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun. “The long-term increase in solar irradiance is heating both Earth and Mars,” he said.
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“- A partial pressure of gases that is different from that which most humans are used to.
– A lack of carbon dioxide in the air, which leads to irregularities in a person’s breathing mechanism.
– Anthony”
please pardon my ignorance, but why is there less carbon dioxide in the air at Vostok Station? Would a person climbing Mt Everest face similar challenges?
–dean
“”” “”” dean (14:21:00) :
please pardon my ignorance, but why is there less carbon dioxide in the air at Vostok Station? Would a person climbing Mt Everest face similar challenges?
–dean “””
Well the altitude at Vostok Station is some 11,443 feet above sea level, so the atmosperic pressure is much lower than at sea level.
People climbing Mt Everest may have similar problems to Vostokese
Could you please use degrees Celsius, like the rest of the world does?
Or if you must use Fahrenheit, please use both C and F?
George E. Smith (11:08:56) :
Hi George,
Thank you for that, you’re a gentleman.
Yes Dome A is one of my favourite sites and I’m happy to talk more about it 🙂
First things first, the sub-surface 10 metre temperature line is a very faint yellow colour and may be difficult to see on your monitor. It is just below the 3m brown trace on this week’s graph at about -57.5C and above the 1m cyan trace which is at -60C today. The mauve sub-surface 0.1m trace is powering away down to -63C as this winter’s cold kicks in. From this we can estimate the ice surface temperature as being no warmer than -63C today and probably lower when the air is still and the temperature inversion is strongest. We can deduce this because the 0.1m sub-surface temperature continues to drop day on day, as the ice surface looses heat to space.
It’s late here and the boss is looking at her watch, so I’ll continue this tomorrow.
now I am totally confused – and yes I revised the phase states via Phil’s reference (thanks)
I think the argument is this
-103 f is cold enough for solid CO2 (at NORMAL pressure -103f is in the SOLID part of the phase state diagram)
to be liquid CO2 needs a pressure of some 5atm.
I do NOT see the relevance of this statement. Surely we have a vapour/solid phase transition at -103C at NORMAL pressure ?
So is -103 f cold enough at 1 atm for a vapour/solid (deposition) phase change ?
If the answer is YES then surely there may be some deposition
So what we have is a problem in the title – NO CONDENSATION is not possible BUT deposition IS and you will be able to find solid CO2 …
I think that is where I got confused; can some one (Phil et al) confirm ??
well Hans; we don’t really use Temperature any more when it comes to climate; we use anomaly instead, in which case it only matters what the base line period is; and degrees don’t matter.
This is done for the benefit of Al Gore, so he can plot graphs without a scale.
But it wasn’t us that gave the world the Fahrenheit degree. Why on earth would anybody set the zero of their scale at 32 instead of zero; and why would they have a range of 180, instead of 100
I like Kelvins myself; but then the guy’s name wasn’t even Kelvin anyway.
I don’t think we invented barns or parsecs either; let alone using the barn parsec as a unit of volume; I would steer clear of that one if I were you.
And what was the point of that 1/10,000 of the earth’s quadrant of latitude though Paris; that’s nearly as arcane as the size of somebody’s foot; everybody caries a couple of Paris quadrants in their pocket.
But i’m with you on old F. I get tired of the add 40, times 5/9 or 9/5, and subtract 40 ritual; never can tell if I’m going the right way.
We’ll take up your suggestion.
just noted I had a major mis-typing session & kept using 103F instead of 113F
Can I suggest that we have reached a conclusion, and sorry, Steve Goddard, but in this case you are incorrect and it is time to review your understanding of the matter. It is quite clear from the relevant equations and data that at the current CO2 concentration in the atmosphere, that it will not condense until the temperature reaches around -140 C. Thus at -90 at Vostok there will be no CO2 ice formation under normal circumstances. Thank you Phil, Dennis. George, and others.
If one was to create an area of high concentration CO2 at Vostok, one could see condensation if the partial pressure was high enough. Also, it appears, and correct me if I’m wrong, that if one created a block of solid CO2 and put it outside at Vostok at -90, it would not sublime, which seems a little paradoxical.
dean (14:21:00) :
“- A partial pressure of gases that is different from that which most humans are used to.
– A lack of carbon dioxide in the air, which leads to irregularities in a person’s breathing mechanism.
– Anthony”
please pardon my ignorance, but why is there less carbon dioxide in the air at Vostok Station? Would a person climbing Mt Everest face similar challenges?
–dean
Seems to be an inconsistency between the claim of no CO2 to breath and the ice cores at Vostok:
http://en.wikipedia.org/wiki/File:Vostok_420ky_4curves_insolation.jpg
How would CO2 get in the ice from the atmosphere and bypass the level humans breath in?
It appears many people do not read the other posts (like Phil’s and Jari’s and mine). If the CO2 were at a pressure of one atmosphere (that is the local atmosphere were almost totally CO2), there would be some CO2 frost forming at -113 F. However at the actual concentration of 385 ppm (at sea level) the partial pressure is only about 0.3 torr, and the temperature to form CO2 frost is -220 F (-140 C). At higher altitudes, the partial pressure is even lower, so the temperature to form CO2 frost is even lower. Please read the other posts and quit going back and forth on total vs partial pressure as being critical to the process. CO2 frost cannot form at Earth’s poles.
peter_dtm (15:45:28) :
> I think the argument is this
> -113 f is cold enough for solid CO2 (at NORMAL pressure -113f is in the SOLID part of the phase state diagram)
CO2 can exist as a solid at that temperature or lower or a little higher.
> to be liquid CO2 needs a pressure of some 5atm.
> I do NOT see the relevance of this statement.
It has no relevance in this discussion unless someone were to start talking about CO2 fire extinguishers containing liquid CO2. And that would be Off Topic, which never happens. Or “I wonder how a CO2 fire extinguisher would work at Vostok?” But you didn’t hear that from me.
> So is -113 f cold enough at 1 atm for a vapour/solid (deposition) phase change ?
Yes, but…. If the atmosphere is all CO2, then deposition will occur. At Vostok it isn’t, and a block of CO2 will sublimate and none will deposit.
> So what we have is a problem in the title – NO CONDENSATION is not possible BUT deposition IS and you will be able to find solid CO2 …
Condensation and deposition are essentially the same. The title has a question mark: “CO2 condensation in Antarctica at -113F?”, the answer is “No!”
At a molecular level there’s always an exchange of CO2 molecules between ice and vapor. The warm (relatively speaking) ice will be shedding molecules readily, but the low vapor pressure of CO2 in the air means not very many CO2 molecules will be hitting the ice or be captured by it.
Down at -140F, then the ice will really hang on to its molecules, and it will be releasing about as many as it captures from the air. Below that temperature, CO2 vapor will condense faster than the ice sublimates, but it will be a slow process.
Hope this helps!
BTW, if the CO2 extinguisher is left outside, it will be frozen solid so you should throw the block of dry ice at the fire you want out, and light a new fire to heat up the extinguisher.
I’m sure that doesn’t help. 🙂
George E. Smith (15:52:31) :
> But I’m with you on old F. I get tired of the add 40, times 5/9 or 9/5, and subtract 40 ritual; never can tell if I’m going the right way.
Hey, that’s the formula Dad taught me! So much better than the infinitude of other formulae. It’s 9/5 going to F – I remember it because Fahrenheit temps are larger than Celcius except in a rather small range.
$ units 2438 units, 71 prefixes, 32 nonlinear units You have: barn You want: cm^2 * 1e-24 / 1e+24 You have: parsec You want: m * 3.0856776e+16 / 3.2407793e-17 You have: barn * parsec You want: furlong^3 * 3.7903023e-19 / 2.638312e+18 You have: barn * parsec You want: nanogill * 26.084793 / 0.038336513I.e. a barn parsec is 26 nanogills. Remarkable something that long can be so small.
AndyW35 (10:02:22) :
“The great thing about science is that theory has to be proved by experiment and therefore before anyone says that Steve’s claim of –
“According to Weather Underground, Vostok, Antarctica is forecast to reach -113F on Friday. That is four degrees below the freezing point of CO2 and would cause dry (CO2) ice to freeze directly out of the air.”
One thing needing to be shown is the concentration of CO2 in the air at Vostok.
Glenn (18:31:12) :
One thing needing to be shown is the concentration of CO2 in the air at Vostok.
Would the South Pole do?
http://cdiac.ornl.gov/trends/co2/graphics/South_Pole_CO2.jpg
Phil. (23:48:13) :
“Glenn (18:31:12) :
One thing needing to be shown is the concentration of CO2 in the air at Vostok.
Would the South Pole do?”
http://cdiac.ornl.gov/trends/co2/graphics/South_Pole_CO2.jpg
Would the latest measure be the same at all altitudes and locations?
Ed Snack
In order for CO2 to sublime, energy is needed to overcome the heat of fusion. At the lower temperature at the South Pole, the cold surrounding would result in a low heat transfer rate, so it would sublime slowly. Nevertheless it would sublime. If a CO2 block at atmospheric conditions anywhere is put in a well insulated container, again the heat transfer rate would be greatly reduced, so it would sublimes slowly. Don’t confuse energy for phase changes and energy flux rates with steady state processes. CO2 will not condense/freeze at the South Pole period.
Ric Werme
That is -140 C not F. This corresponds to -220F.
If the temperature were below -71 F, a CO2 fire extinguisher would have solid CO2 inside, but would still be at a slight pressure. Below -108 F, the pressure would be below atmospheric. In all cases below -71 F, they would not work.
Hans Errin
I also wish all would use C rather than F. Having both (like feet and meters) is a possible source of error. A spacecraft was lost due to the feet to meter problem. However, the Americans and British insist on holding on to feet and F, so you have to grin and bear it.
Correction on temperature units to Praxair’s The facts about Carbon dioxide
Glen, Phil
No CO2 in air at Vostok:
http://www.absoluteastronomy.com/topics/Vostok_Station
Anthony sent me this when I was blabbing on about a way CO2 could concentrate in the region (high CO2 in the cold water, outgassing when freezing)
Dry ice placed in a -82C freezer overnight in an open container completely sublimated overnight. Dry ice placed in a zip top bag (so that the atmosphere in the bag with the dry ice would be nearly 100% CO2) retained >90% of its mass. Anthony has pictures.
Answer: For normal atmospheric concentrations of CO2, at -82C it sublimates faster than it freezes. CO2 “snow” will not accumulate at Vostock station or anywhere else.
REPLY: Agreed. Tom sent me photos via email showing this, and I’ll put up a summary post tonight. Tom if you are reading, I sent you an email, some of the photos sent I can’t open. Can you place them on an http or ftp server someplace for direct download? Please reply to my email sent.
– Anthony
Well, since a consensus seems unlikely, we should form a committee to lobby Catlin to send an expedition. In short order the answer will be known beyond all reasonable doubt.
Regarding the information from Praxair, they have erroneously given a “boiling point” temperature of -56.6 C at 1 atm. This is the temperature of the triple point (-56.57 C), which occurs at a pressure of 5.185 bars (5.117 atm). The definition of the triple point precludes liquid/vapor thermodynamic transitions at lower pressures. Please consult the Wikipedia entry on carbon dioxide [en.wikipedia.org/wiki/Carbon_dioxide, with extended data page at en.wikipedia.org/wiki/Carbon_dioxide_(data_page)].
I cannot determine the “state” of the discussion at this point, but I would like to remind everyone that physico-chemical state diagrams are premised on the pressure of the chemical constituent. The boundary between liquid and vapor (or solid and vapor) represents the vapor pressure in equilibrium with the liquid (or solid) at that temperature. Adjacent to the surface of the material, that is the pressure of the vapor that may be evaporating or subliming—provided that the partial pressure of that compound in the ambient air is lower (so that the vapor can physically diffuse away from the surface). If the partial pressure of the compound is higher, there is no way for evaporation or sublimation to occur, and instead the vapor will condense or freeze. Don’t get hung up on partial pressure vs. total pressure as signifying some kind of mechanical environment. So far as these processes are concerned, partial pressure is directly analogous to a chemical concentration.
lweinstein (04:49:41) :
> Ric Werme
> That is -140 C not F. This corresponds to -220F.
Oh dang. I almost went and checked before I posted. That does it – I’m not posting another Fahrenheit temperature in any discussion that involves CO2. Thanks, I likely would have used that bogus temperature elsewhere.
I may also silently convert F->C in anything I quote too.