CO2 condensation in Antarctica at -113F?

How cold is it in Antarctica? 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.

Uhm, no. Vapor pressure and all of that.

our utility is going to start charging an additional tax of $1.00 for over use of power.
http://www.cherrylandelectric.com/

jorge,
I think your beer would be frozen solid at -113F.
I wonder when legislation will be passed requiring reduced carbon or no carbon beer?

In the National Geographic link mentioned by the article was the following statement:
“without the greenhouse effect there would be very little, if any, life on Earth, since our planet would pretty much be a big ball of ice,” said Evan, of the University of Wisconsin.
Is this really true? Surely our oceans do a better job as a heat sink than the atmosphere, and they teem with life.

Dome A has been around -70’C for the last two days:
http://www.aad.gov.au/weather/aws/dome-a/index.html
I’ve asked this before, but can anyone explain why the Subsurface 10m temperature is always slightly lower than the temperature at -3m? Sensor wires or graph labels mixed up?

Steven Goddard (00:08:31) :
Oh, how absolutely Green of them… Have an ice cold frosty Flat Coors.
The Carbon Police will be raiding illegal pubs looking for anyone selling carbonated drinks.
“what are you in for?”
Running carbonated beer.
“stay away from him, boys, he’s crazy”.
No champagne. No sodas. No beer. No seltzer water.
The New Prohibition.
The Carbonance Movement.

“But if CO2 did freeze in Antarctica during the winter”: it doesn’t, it can’t; don’t you understand, the temperature at which pure CO2 gas at one atmosphere pressure would solidify is far, far higher than the temperature at which some CO2 frost would form from air where the CO2 constitutes just a few hundred ppm! The stuff squiddly quotes is just rubbish.

Re Squidly (23:25:51) :
According to data in my books CO2 sumlimes at -78.5°C at 1atmosphere pressure. The liquid phase is only possible at a minimum pressure of 5 atmospheres, where the solid melts at -56.7°C.
Given that the partial pressure of CO2 in the atmosphere is about 0.0004 atmospheres, at -80°C (~-113°F) freezing it out of the atmosphere would not be possible – or am I missing something?
Mike

@Paul H Clark
The BBC blog is a double act.
http://www.bbc.co.uk/blogs/climatechange/2009/06/the_unpredictable_weather.html
Richard Cable has wandered off the reservation and has questioned the computer models, the UN ‘300,000 dead’ claims and even the ludicrous Catlin Climate Cadets.
Meanwhile, Shanta Barley goes on a jolly to the Hay Festival and seems to be writing for a school newsletter.

“I’d go for CO2 frost at the south pole whenever the temp dropped below -109°F. ” No, Mike, no. Only if the atmosphere were 100% CO2. Look, the condensation point of water vapour is 100C. That is to say, if you have pure water vapour (= steam) at one atmosphere pressure in a container and you reduce the temperature from something higher down to 100C, it begins to condense. Now consider an impractically hot day. If you reduce the air temperature to 100C, does that mean that the water vapour in the air begins to condense? Of course not, because the atmosphere isn’t pure water vapour. The dew point, at which water begins to condense, is far, far below the condensation temperature for (pure) water vapour. And similarly for CO2.

Mike (02:35:19) :
Re Squidly (23:25:51) :
“According to data in my books CO2 sumlimes at -78.5°C at 1atmosphere pressure. The liquid phase is only possible at a minimum pressure of 5 atmospheres, where the solid melts at -56.7°C.
Given that the partial pressure of CO2 in the atmosphere is about 0.0004 atmospheres, at -80°C (~-113°F) freezing it out of the atmosphere would not be possible – or am I missing something?”
Not sure, but no one has shown Steven to be wrong. At first blush it would appear that everything in the atmosphere is under a certain pressure under certain conditions, including CO2, regardless of it’s concentration. Your figure if correct would be the atmospheric pressure of a pure CO2 atmosphere, which of course it is not.

TonyS (03:11:13) :
“Are there clouds on Mars?”
http://mars.jpl.nasa.gov/MPF/science/clouds.html

Steven Goddard (00:08:31) :
jorge,
I think your beer would be frozen solid at -113F.
I wonder when legislation will be passed requiring reduced carbon or no carbon beer?

Beer is a basic human, if not civil, statutory and constitutional right. If it’s not protected, explicitly, it should be.

Two short remarks:
– the opposite of sublimation is deposition, not freezing (which is associated with melting)
– deposition will only take place (as was mentioned) if the partial pressure of CO2 in the atmosphere becomes higher than the solid-gas vapor pressure of CO2 at the temperature of interest. I really doubt it is the case, given the low pCO2 we have here.

If you want to hold the conference in Vostok next week, I’d advise all male attendees to visit a sperm bank before going……..you never know what might happen to you down there…….

” Does anyone have any information about this? ”
I have asked this question before in previous threads. There must be information tracking the temperatures of other nearby planets. Surely the correlation of these planetary temperatures with that of the earth (warming spells followed by cooling spells), although tempered by many factors on each of the planets (clouds, %land mass, atmospheric makeup, etc) would suggest that the big glowing thing in the sky (i.e., our sun) is primarily responsible for the ups and downs of temperatures on the earth and other nearby planets. To me, this is crucial information, but I have yet to find it anywhere.

Boy, the arctic ice extent is dropping fast the last few weeks… Wonder why?

Maybe the great Ray Bradbury will, as he approaches the age of 90, add a chapter to __The Martian Chronicles__around the theme of playing hockey on the ice caps of the fourth rock from the Sun.
I’m sorry; I’m just being puckish.

If any freezes out, it will likely be trace amounts.
It would be interesting to test in a lab condition with sensitive instruments.

I was thinking about dry ice last week and thought if carbon taxes or carbon trading took effect, how damaging would it be to dry ice manufacturers and ice cream makers (they use dry ice)? Or would they be seen as part of the solution?

We have a number of posters here boldly proving that according to their misinterpretation of how phase diagrams work, polar ice caps can’t exist on earth. Look at the phase diagram for water.
http://www.lsbu.ac.uk/water/phase.html
Water vapor partial pressure near the poles is close to zero during the winter. Using the brilliant interpretation of Phil et al, the freezing point of water in Antarctica and the Arctic would be close to -70C, and there could be no ice.
The reason why water freezes at 273C is because of the atmospheric pressure of 1KPa, not because of the partial pressure of water – which is much lower, and varies hugely from the poles to the tropics.
The freezing point of water (and CO2) is fixed by the atmospheric pressure – not the partial pressure. Likewise, the boiling point of water is fixed by the atmospheric pressure and is independent of the humidity or partial pressure of water in the air.
Does Phil also believe that water boils at room temperature on earth, due to the low partial pressure of water?
http://en.wikipedia.org/wiki/File:Water_vapor_pressure_graph.jpg
As usual, Phil got distracted and missed the point of the article – which is wondering whether the Martian ice caps have stopped shrinking.

A bit OT –
Here we go with the newest study, hot off the AP:
http://news.yahoo.com/s/ap/20090610/ap_on_sc/us_sci_diminishing_winds
Winds are dying! It’s global warming again. Wind power is doomed!
And, from highly respected (*choke – cough*) scientists –
M. Mann – sounds about right
G. Schmidt – no they’re not
So much for a monolithic AGW movement. There are caveats in the study, but as usual, those will be forgotten in the quest for headlines.

It is rather ironic this polar cap is frozen CO2 isn’t it. Has any one of you clever people out there observed a time frame for this Anthropological Marsian Warming. There must be photographic evidence of the Marsian Polar Cap from previous space expeditions for comparison, surely? The time frame I would assume have some sort of periodicity coupled with the greater eliptical orbit that Mars has.
As to the apparent change of heart by the BBC displayed in the two recent posts they’ve made & commented on above, the cracks may be getting bigger, Dr Pope claiming alarmists are damaging the cause & claiming that Arctic sea-ice melt could be perfectly natural after all, etc. as I have pointed out elsewhere, they are doing the backside covering exercise many do when it starts to look like the game is up, people are beginning to know it, they become all embarrassed, feeling awkward, so they hedge their bets to save faces by reducing the level of commitment to the cause. This way, they can turn around to their accusers (& there will be many rightly or wrongly) & imply they were innocent all along! I must say this really is quite an extraordinary turn of events fromt he BBC, probably the most staunch supporter of AGW. They recently made cut backs in certain departments & arch AGW eco-champion Roger Harrabin had to walk! Roger Black appears to have been rather quiet too of late.
Could it be that they are becoming eh……..what are the words I am looking for, for a publically funded organisation, eh……oh I know, IMPARTIAL, FAIR, & BALANCED in their reporting of Global Warming!

Thanks Steven Goddard, a beautiful photograph: She’s LA NINA laughing of all Gwrs, while breathing a little of refreshing cold CO2.
Philip Johns: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. That were his words about 1997-1998 el Nino warming, now he says:
We expect that the next relatively deep minimum of the solar activity, radius, and radiation flux in the 200-year quasi-cycle will be close to the Maunder minimum level and will occur in the year 2040 ±10.
http://www.giurfa.com/abdusamatov2.pdf

“During the ice ages, more [CO2] probably froze out and accumulated, effectively removing carbon dioxide from the atmosphere and contributing to the cooling of the atmosphere.”
–David R. Cook, Atmospheric Research Section, Environmental Research Division, Argonne National Laboratory
One more reason why fossil plant stomatal index (SI) studies indicate 320ppmv to 360ppmv CO2 during periods in which the ice core data indicate 285ppmv.
If the plant SI data are more analogous to the modern instrumental CO2 record than the ice core data are…385ppmv is not particularly anomalous.

“I must say this really is quite an extraordinary turn of events fromt he BBC, probably the most staunch supporter of AGW. They recently made cut backs in certain departments & arch AGW eco-champion Roger Harrabin had to walk! Roger Black appears to have been rather quiet too of late.”
No, Roger and Richard are still around and the BBC’s reporting line has not changed at all
http://news.bbc.co.uk/1/hi/sci/tech/8092866.stm

Flanagan,
The nucleation of ice is dependent on many factors. Frost will form on a dirty windshield but will not form on a clean one. In the upper atmosphere, ice can nucleate around salt particles and dust at extremely low humidities.
The point of mentioning that Vostok is running below the dry ice freezing point was tongue in cheek and was merely intended to point out that Antarctica is incredibly cold. This article is about the current opportunity to test Dr. Abdussamatov’s theory of solar induced global warming.

crosspatch (23:18:31) :
How cold is it in Antarctica? 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.
Uhm, no. Vapor pressure and all of that.
————-
Can’t see that vapour pressure has anything to do with it. At 20 deg C, the vapour pressure of atmospheric humidity is a little over 2,3 kPa, within a sea level atmospheric pressure of 101 kPa. Thus, in a sea level environment which happens to have a dewpoint of 20 deg C, an object at 15 deg C will sweat. Atmospheric moisture will sublimate onto an exposed pipe surface which is at minus 5 deg C, yielding frost. (eg. The compressor suction valve of a freezer refrigeration application). These situations are absolutely commonplace, and are plainly observable. The situation with atmospheric CO2 cannot be any different, save for the difference in operative temperature.

Keith W (08:45:23) :
[…]
What effect is there on the chemical composition of air bubbles trapped in the the deepest ice cores from the extended pressure and temperature difference on those deepest cores?

According to the ice core folks…There are know effects from burial or the core extraction process.
But there are at least three other estimates pre-industrial CO2 levels…
1) 19th Century direct measurements ranged from 280ppmv to 550ppmv.
2) Becks’ recent chemical analyses yielded 300ppmv to more than 400ppmv.
3) Plant stomatal studies yielded 320ppmv to 360ppmv.
The ice core data put the pre-industrial level at 285ppmv. It fits the narrative; so it’s the one that’s used.

Does anyone know of laboratory-controlled validation tests of the chemical composition of air bubbles in ice tested under the same pressure and temperature as that from the deepest ice cores themselves?

I’m not aware of any.
On the other hand, plant SI data can be empirically calibrated and SI data over the last 60 years (Wagner, 2004) correlate very well with Mauna Loa and other modern instrumental records.
So…The warming of the late 20th century was not anomalous…And if the plant SI data are correct, 385ppmv CO2 is not anomalous.

Re: Geoffrey Alder
Vapour pressure and partial pressure has everything to do with – suggest you look at this link to understand principles at work here. http://en.wikipedia.org/wiki/Dew_point

16,500 condoms at McMurdo – but are there any women?
http://abcnews.go.com/International/story?id=5027989&page=1
Best not to think about that too much.

Bin there and done that……We had this discussion ages ago; and I was one of the proponents of CO2 freezing out of the atmosphere at Vostok.
_113 F is mega global warming at Vostok Station, where the temperature can get down to -90 C (-130 F).
And I believe it was Phil back then who disabused me of my silliness.
Even at -90 C the vapor pressure of CO2 is way above 385 ppm of earth’s atmospheric abundance.
And I have the phase diagram of CO2 right under my nose, thanks to Phil’s tuition.
Man; the thrill one gets when you finally understand some of this stuff and can yell Eureka ! I got it, how could it ever have been so hard to understand.
So Nyet ! on the Gopher getter ice at Vostok; we are cleansed of that science pestilence once and for all.
Thanks Phil; dunno how to thank you for the insight; whatta dummy I am at times.
I wouldn’t want to be David R Cooke; at the Argonne labs; maybe tomorrow, his boss is gonna walk up to him and say; David you Ar gone from this place. We’re hiring Phil in your stead.
George

@Indiana Bones (10:24:31). In England, English is spelled differently than it is in Indiana. The first B in BBC stands for British. I hope this helps.

Much as I love this site, I think this type of posting feeds the fire at other blogs that make the claim that WUWT is unscientific or posts poorly substantiated claims.
As has been aptly described above, CO2 will not sublimate at the temperatures described at normal air pressures. This should not have been posted as a topic.
Thanks
Ed

Phase diagrams are for pure substances and assume ideal gas behavior, neither of which are applicable to earth’s atmosphere at very low temperatures.

“”” Steven Goddard (10:42:14) :
Phil,
The boiling point of water is independent of the humidity of the atmosphere, just as the freezing point of water is. The boiling point of water at the South Pole is depressed because of altitude (atmospheric pressure.) Why are you spreading rubbish? Ice gets thicker every year in Antarctica, despite the extremely low vapor pressure of water.
2-D Phase diagrams refer to atmospheric or ambient pressure, not vapor pressure or partial pressure. Why don’t you censor yourself instead of spreading nonsense? “””
Imagine a stiff solid container with a moveable plunger; a cylinder if you will.
So we fill the cylinder up with water occupying all the space; so there is no atmospheric gas at all in the cylinder.
Now we can apply pressure from negative to positive to the water. Water vapor will escape if we pull the plunger away from the water (or try to), and any small space will fill with water vapor at whatever the saturation vapor pressure is at whatever the water temperature is.
Now if we heat the container and its contents, the vapor pressure will rise. if we heated it to 100 deg C, the vapor pressure would reach 760 mm of Hg pressure which is the normal atmospheric pressure. But so long as we apply more than that presure with the piston; the water will not boil. If we lowered the pressure on the piston, the water would boil before it got to 760 mm or 100 deg C.
The boiling point is simply the temperature at which the saturated vapor pressure becomes equal to the ambient pressure; whatever that pressure is.
Water boils at Vostok station at 90 C because it is 14,000 or so feet high, so the ambient pressure is lower.
The thing that is different about boiling is that since the saturation vapor pressure is equal to the ambient pressure, then bubbles of saturated vapor can form inside the bulk of the liquid; so the evaporation is no longer constrained to the open surface, like ordinary evaporation is.
Actually in order for the vapor bubbles to form, the internal pressure has to exceeed ambient by 2T/r, where T is the surface tension of water, and r is the radius of the bubble. Since r must presumably start at zero, the required internal overpressure would be infinite, which is why very clean water can sauperheat and fail to boil at the appropriate temperature. So dust particles or even cosmic rays can start superheated water boiling, by providing a non zero starting radius for the bubble (neve nuke clean water to make coffee; always put the coffee in first to allow finite radius bubbles to form, should the temperature get to boiling.)
I found some Vostok temperature record data on their website; and in addition to the daily temperature plots they also plotted the dew point, which mostly was always below the ambient temperature; so the humidity was less than 100% most of the time.
Under those conditions the equilibrium would normally move towards evaporation; or in this case sublimation since we are way below the triple point for water.
I believe that temperate or tropical ocean evaporation brings moist air over Antarctica all the time, which greatly exceeds the amount of water the colder air is capable of holding, and it is that moisture which provides the constant thickening of the Antarctic ice sheets; whcih continue to grow.
But when all that excess moisture deposits out as new ice; the humidity can still drop below 100% so the dew pint falls below ambient.
The dry ice on Mars is there because the bulk of the atmospheric pressure is CO2, and the polar temperatures are way colder than the triple point.
At 1atm (760 mm Hg) I have -78.5 C for the sublimation point; at 76 mm it is about -100, and at 7.6 mm it is about -120 C. Not sure what Martian atmospheric pressure is but if we used parachutes to slow stuff for landing, I suspect it is more than 1% of earth pressure.

When the air temperature is below 0˚C, all the water does not immediately freeze out. The question is, how cold does it have to be for ~300ppm of CO2 to condense onto a cold surface.

Adam from Kansas (10:33:04) :
Is there any legitimacy in this?
…
They seem to be forecasting a heatwave …
They were produced by the Center for Ocean-Land-Atmosphere Studies (COLA). “COLA and IGES make no guarantees about and bear no responsibility or liability concerning the accuracy or timeliness of the images being published on these web pages. … These products are not a substitute for official forecasts and are not guaranteed to be complete or timely.”
The President of COLA is Jagadish Shukla, who among other things was Lead Author (2007), Intergovernmental Panel on Climate Change (IPCC). I believe he’d be predicting a heatwave if the daily high in Panama City was -10C in the middle of August.
To answer your question, I doubt they’re worth the electrons it takes to transmit and render them.

REPLY: Maybe so, but for us that don’t deal with the subject every day, could you provide a link or citation for “CO2 doesn’t have a freezing point at a pressure below 5.11 atm”. I’ve looked for references about CO2 freezing point and pressure, and so far have found none. I’ll be away for a bit, so take your time. – Anthony
I don’t think Phil understands the phase diagram. From the Wikipedia article on dry ice,
In 1835 the French chemist Charles Thilorier published the first account of dry ice.[3][4] upon opening the lid of a large cylinder containing liquid carbon dioxide, he noted much of the carbon dioxide rapidly evaporated leaving solid dry ice in the container.
I’m prepared to believe that the behavior of trace amounts of CO2 in air is different than that of pure CO2, just as the behavior of trace amounts of water vapor in air is different than that of pure water. But Phil, even if you were 100% right your behavior is appalling, and you are not 100% right. I wonder what university you are affiliated with.

In my misspent youth, I was a Cryogenics Cargo Engineer on a couple of 125,000 cubic meter LNG tankers. We carried about 125,000 cubic meters of Liquefied Natural Gas cooled to minus 158-160 C. It was my job to maintain/operate the cargo handling equipment. I was on several runs back then: from Algeria to the East Coast of the United States, later between either Sumatra or Borneo to Japan.
http://en.wikipedia.org/wiki/LNG_carrier
If anyone cares, one load port is at Bontang, Borneo. It is on the east coast, eight miles north of the equator. Google Earth shows a tanker similar to the one that I was one with five spherical cargo tanks. (It is in the harbor at the end of a long pier-it “crosses the “T”.)
The tanks I am familiar with were some 33 meters in diameter and made of aluminum (aluminum doesn’t display a non-ductility transition at low temperatures as does carbon steel).
The loading/discharge piping was not insulated so the surface temperature of the lines dropped to near the temperature of the cargo during the times we were loading or discharging.
Finally to the point:
When we disconnected the pipe lines, we had to remove the ice before un-bolting the joints. At that time, the solid CO2 and mixed with the water ice would crack and pop on the deck, especially if it had been raining.
So……
Yes, I know from personal experience that CO2 will condense out of the atmosphere. I don’t know from that experience the temperature at which it first starts to condense.
Regards,
Steamboat Jack

Based on my mental model of what happens to gas molecules under pressure, I would think the pressure of the mixture of gases would be what applies in these phase diagrams. It’s also quite possible that it is neither partial pressure nor mixed gas pressure but something intermediate. I seem to remember a college chemistry lab that involved determining the eutectic point of a solution of waxes. This brings up the next question: is a mixture of gases a solution or just a mixture?
Richard Alley in his book “The Two Mile Time Machine” describes ice popping and snapping after deep samples are relieved of pressure on them. ( see page 49 and 50 of the preview at http://press.princeton.edu/titles/6916.html ). I always wondered if he was entirely correct about that since we’ve all heard ice cubes crack when making cocktails. I also wondered if he handled the cracking of the ice in the best possible way. It occurred to me that letting the cracking process occur could change the data being collected, and there was no mention of trying to contain, collect and analyze anything coming out.
Being a skeptic has natural advantages. All you really need to demonstrate is that the other guy is ignorant and hasn’t imagined all possibilities.

Again, the phase diagrams are for atmospheric pressure – not for partial pressure of the compound. For example, the boiling point of water is a function of atmospheric pressure – it is not a function of humidity. Water boils at the same temperature in the desert and jungle.

Now please, are you actually making a debate out of this? Maybe we could discuss also for hours whether 1+1=2?
It’s so obvious that the CO2 pressure will affect the deposition temperature I don’t really know how to say it in another way. Maybe this one: CO2 will deposit at -70 degrees whatever the CO2 pressure, in your opinion. It would all depend on the global pressure… So if one has an atmosphere with no CO2 at all, following these arguments, it should solidify anyway at -70? No molecule, but deposition? Mmmmm….
REPLY: The purpose here is to find out the true answer, we have authoritative answers from both sides. Drop the snark or find another blog to bother. – Anthony

On the phase diagrams the pressure is atmospheric which is going to be somewhere in the area of one atmosphere in the Antarctic. (and is of course somewhat variable)
I have no idea how a value of 0.3 torr has anything to do with the phase diagrams for natural conditions on Earth. Please explain.

Below the freezing point of a gas, it can exist as a solid. In the winter, we see the transition from gas to solid as frost. Frost occurs even at extremely low humidities.
There are other things going on as well. The ice may be getting hit by photons or other energetic particles which cause them to convert back to gas. This can be seen when the ice is exposed to sun or wind, even on a very cold day. The higher the humidity, the greater the tendency for water molecules to form ice. This phenomenon is not covered by phase diagrams, which simply show the preferred state at a given ambient temperature and pressure.
At -113F and 1atm, that state would be solid for CO2.

@TonyS… Here another article on clouds on Mars:
http://www.sciencemag.org/cgi/content/full/sci;282/5396/2053?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=clouds+on+mars&searchid=1&FIRSTINDEX=20&resourcetype=HWCIT
Fragment of the abstract:
“Clouds observed over the polar cap are likely composed of CO2 that condensed out of the atmosphere during northern hemisphere winter.“

There is nothing magical about -140F, just as there is nothing magical about Hansen’s Armageddon value of 350 ppm CO2 . The freezing point of CO2 at 1 atmosphere is -109F.
Once again, the phase diagram for CO2 does not consider the partial pressure of CO2. It considers only the atmospheric pressure, which is much higher. The equilibrium between sublimation and deposition is a complex function of wind, sun, chemistry, surface roughness, etc. and can not be inferred from a phase diagram.
The case we are all familiar with is frost forming on a dirty windshield, but not on a clean windshield – with everything else identical.

The phase diagram shows unambiguously that the equilibrium state of CO2 at one atmosphere at 113F is solid. The freezing point of CO2 is -109F at 1 atmosphere.
http://www.chemicalogic.com/download/co2_phase_diagram.pdf
I see Phil has created a new magic number of -130F.
Personally, I think the world was doomed at 300ppm CO2. I’ve got work to do. l8r

The atmospheric pressure of Mars is less than 1% of earth.

So basically everyone is correct, the argument is one of at what temperature it happens? By the way −128.6°F is not that far off -140F, just 8’K or 4.5%?
“At this point, after doing research of my own, including a telephone call to a local expert on compressed gases (since I am no expert in that field) and reading comments, particularly that of George E. Smith which answered the question in my mind of why we could have solid to gas phase transition of CO2 (sublimation) but not the other way around (at least at -113F) I’m ready to call this myth of CO2 “snow” condensing from the free atmosphere at the south pole at -113F as transitioning from “plausible” to “busted”.
Though, it will happen in the free atmosphere at -140F, of that there is no doubt, but since the coldest natural temperature ever recorded on Earth was −89.2°C (−128.6°F) at the Russian Vostok Station in Antarctica July 21, 1983, I don’t think we’ll see this effect in the free atmosphere today, and I sincerely hope I never witness it firsthand ;-)”

“”” George E. Smith (13:52:09) :
The triple point of CO2 is -56.6 deg C at a pressure of 5.11 atmospheres; that’s 3883.6 mm Hg pressure.
Below that temperature, liquid CO2 canot exist. At zero degree C you can liquify CO2 at a pressure of about 15-20 atmospheres, and solidify it at about 1000 atmospheres.
In the case of the Antarctic plateau, the CO2 vapor pressure stays about constant at around 0.447 mm Hg, and that is not enough to stop continued sublimation till the temperature is about -140 deg C.
So any remaining amount of CO2 ice would be very hard to locate at -113 deg C.
REPLY: Well said, and without labeling anyone, insults, or snark being tossed. Phil. could learn a few things from you. BTW I think you meant -113 and -140 deg F – Anthony “””
Well thank you Anthony, and yes that was supposed to be F rather than C.
When we had this discussion before; I was pretty darn sure I was right; particularly since I ran into a chap who had been to the south pole and he claimed he had been walking around on dry ice at the south pole, and it wasn’t anywhere near as cold as Vostok. And I thought I understood it; because I sure know what happens with the vapor pressure of Arsenic over hot gallium Arsenide in a diffusion sealed ampoule.
But Phil; and I believe it was Ric Werme kept insisting I was wrong; and I couldn’t see it, till I had the phase diagram that Phil posted; and I started thinking about the fact that it is a dynamic equilibrium if both species coexist like water vapor over a dish of water under glass, and then I could see that no reasonable amount of dry ice could survive even at -78.5 C because it would all evaporate without raising the population of CO2 molecules in the vapor phase to where the rate of returning molecules to the solid surface increased enough to balance the loss rate.
And once I “got it”, I got mightily embarrassed that I hadn’t seen it on my own without Phil’s and Ric’s prodding. Now I can’t figure out why I didn’t figure it out by myself.
But on Mars since most of the atmosphere is CO2 (90% I believe), then most of the atmospheric presssure; even though it is low is CO2 vapor partial pressure, and it is enough to equilibrate with solid CO2 at the -120 to -125 deg C polar temperatures on Mars. So I have no doubt that CO2 ice does exist on Mars, and pretty much doesn’t on earth; I suppose one could calculate how many molecules of CO2 clumped together, would be small enough dry ice sample to remain in equilibrum with 385 ppm of CO2 in the atmosphere; and at Vostok or South pole altitude where the atmospheric pressure is diminished.
But it was Phil’s nudging that convinced me that it was the partial pressure of the species that had to be in equilibrium with the solid because those are the two parties exchanging molecules. It is true that the total pressure affects the boiling point; because the boiling point is simply that temperature at which bubbles of the vapor species can appear in the bulk of the liquid, because the vapor pressure at that temperature is equal to the ambient pressure. (remembering in the case of at least water with a sizeable surface tension, that there must be an internal excess pressure of 2T/r in the bubble. You can prove this by using the principle of virtual work. Imagine a miniscule increase in radius doing a miniscule amount of work equal to the excess pressure times the surface area times that miniscule radius increase. that has to be equal to the work done against surface tension, which is simply the surface tension (T) timews the increase in surface area due to the radius increase. Put those two equal, and you get p = 2T/r
In the case of a soap bubble you have two surfaces so the internal excess pressure is 4T/r.
George

Mark T (15:48:11) :
Your breath.
Exactly, or even more dramatic, near the exhaust pipe of any combustion engine, generator, boiler, or furnace. These should have significantly higher concentrations of CO2 and could likely lead to CO2 condensation (deposition) at temperatures near -128F.

I think I see where Steve Goddard is getting confused. As George E. Smith points out, boiling is evaporation from inside the liquid, which does indeed depend upon atmospheric pressure, whatever that atmosphere is made of. Evaporation from the liquid’s surface, however, depends on the partial pressure of the liquid and gaseous phases, i.e. the net movement of molecules depends on the number leaving the liquid phase vs. the number entering. Perhaps a good thought experiment would be to compare the evaporation of pans of water in identical sealed terrariums, one of which also has a container of drying agent.
BTW, I bet knowing the vapor pressure of Arsenic over hot gallium Arsenide in a diffusion sealed ampoule makes George very popular at parties! 🙂

SteveG “”Water boils at the same temperature in Phoenix, Barrow and the Amazon.””
No, it does not. The atmospheric pressure due to elevation is different. You are correct, if you are reading the phase diagram correctly. The freezing point for CO2 is set by the pressure, not the partial pressure. Most interesting point is that waters critical point is oC, and standard pressure. One can have water in all three phases at these conditions.

“”” Gary Hladik (16:47:26) :
BTW, I bet knowing the vapor pressure of Arsenic over hot gallium Arsenide in a diffusion sealed ampoule makes George very popular at parties! 🙂 “”
Well silicon process engineers have it very cushy dealing with an elemental semiconductor. The problem with the III-V compounds such as gallium arsenide, is that they are chemical compounds and as such, at elevated temperatures as in a diffusion step, they actually can dissociate and that can wreck a crystal surface that you are trying to make diffusions into.
A dopant source such as a Gallium zinc alloy works fine at low diffusion temperatures, but it cannot easily make high concentration layers at those lower temperatures. But if you use a dopant like zinc arsenide, then it completely dissociates and evaporates, and maintains an arsenic overpressure that stops the crystal surface from decomposing. The vapor pressure of Arsenic over Gallium arsenide is almost one atmosphere at the melting point of Gallium arsenide; so you can diffuse it in a sealed ampoule, with Zinc Arsenide, and not blow the ampoule up.
We had many hundreds of Kg of high purity Arsenic in our building growing about one Kg GaAs single crystal ingots (for LED substrates); more than enough to poison every thing in the known universe; and likely some of the parallel ones too. In 12 years of operations we never once had a single employee ever test positive for arsenic contamination; and every single one who worked with it was tested every month. But the real problem was the Arsine in Hydrogen gas used for growing epitaxial Gallium Arsenide Phosphide on the GaAs wafers. It smells like garlic; which is an odor you never want to get around an LED operation.
No Climate consequences of Arsine that I am aware of.

edit
But it still has to be above it’s equilibrium absolute saturation pressure to condense out .

Actually, the III-V compounds can give us a different input on the H2O versus CO2 situations.
As I said above the saturation vapor pressure of Arsenic over molten gallium arsenide (at the melting point), is slightly less than one atmosphere; so you can safely grow single crystal GaAs by variations of the Horizontal Bridgeman process such as Gradient Freeze; and you can if you want do open tube diffusions into GaAs somewhat below the melting point of course.
On the other hand, Gallium Phosphide has a vapor pressure of Phosphorous at the melting point, that is around 40 atmospheres, so you can’t grow single crystals of GaP in any atmospheric pressure vessel, and it is typically done by encapsulating the melt under Boric Oxide molten glass (so you can see through it) in a high pressure vessel (bomb) at about 45 atmospheres pressure.
That is similar to the CO2 case where you need over five atmospheres of CO2 pressure to have stable liquid CO2.

@Phil, thanks for your postings on this thread. It is important that the science comes first, not people’s egos. If folks don’t like being robustly questioned on their hypotheses then they should not be posting on a website that has an agenda of questioning other theories. Indeed, Phil, your obvious correctness should vindicate the vociferousness of your posts.
REPLY: There is never an excuse for rudeness. – Anthony

Goddard fired from the hip with his comments about the overall atmospheric pressure determining the transition point of CO2, rather than the individual partial pressure. He is fundamentally wrong. This is basic junior year P-Chem. Even in some cases, basic first year chemistry. It’s sad that he fired from the hip in defending himself this way. [snip ]

Experiment? Well, I have a freezer that maintains -80˚C (-112˚F) in my lab, and it can be set as low as -86˚C (-122˚F).
I can already tell you that dry ice placed in the freezer at -80˚C will sublimate, although much more slowly than at room temperature, of course, because I’ve done it many times. I can also tell you that the snow from the freezer does not “pop” when thrown in water the way that dry ice does, but this is an admittedly poor test.
It should be relatively trivial to find 5 or 10 scientists with ultra low temp freezers, and place a weighed cup of dry ice in them to see what happens. I’m willing to do this, although to do it properly would require setting the temp down to -86 in the morning, then placing a weighed cup of dry ice in at at the end of the work day, so the internal freezer temp won’t be disturbed by people opening it up. So I wouldn’t have an answer until 10AM EDT Friday.
But, from my past experience, this is unnecessary. The freezer manuals do not warn about the hazards of CO2 accumulation in the freezer, and I have never, in 20+ years of life sciences research, seen anything that looks or acts like CO2 snow. (I can tell you, however, what happens if you put a glass 20oz bottle of diet coke in the freezer to chill it, and then forget it’s there. It’s not pretty.)
In fact, I’m rather embarrassed that I did not think of this rather obvious answer earlier. I’ll run the experiment if you want.
REPLY: Hi Tom, Yes we’d love to see it, especially if you can take a photo or two along the way. Thanks for your kind offer. – Anthony Watts

So 1 m^3 of freezer space contains 380 cm^3 of CO2, ignoring colder => denser, this is approx .38/22 moles of CO2 @ 44g / mol, ie. 0.76 grams .
As a quick bodge temp correction multiply by 300K/180K => 5/3 so I’ll offer 1.25g per m^3 as max achievable CO2 frosting.
I’d be interested to know how you’ll get all the frosting to occur on the CO2 block?

Anthony, it may be staring me in the face, but I don’t see a direct email address for you. Email me at the address I’m using for this post so I can email you the photos and results.
REPLY: sailing through the ether as we speak.

Well Anthony thank you for your personal implication in this stuff, and for the courage to recognize faults when you see them, even on your own blog :0)
I hope this will settle the discussion, because it looks like these comments could go on and on for ever. IMHO this is because there is no “authority” on a blog. Even if I (or you or Phil or any other) says he’s a “specialist” on a topic, the absence of direct dialogue and possibility to verify such assertions provoke never-ending discussions.

Unfortunately Steven Goddard got this one completely wrong.
The Argonne scientist got it wrong too.
Phil is correct in this case.
CO2 phase diagram is very simple in comparison to water phase diagram. Please study it. It is all in that diagram.
The sublimation temperature of CO2 at 1 ATM is -78.5 C. At this temperature the vapor pressure of the solid CO2 is equal to the total pressure of the gas phase in contact with it which is 1 ATM. If the atmosphere would have 100% CO2, the pressure is 1 ATM and the temperature is -78.5 C, then an equal amount of CO2 is deposited as solid as is sublimed as gas. Things would be in balance. Again, if the atmosphere is 100% CO2, pressure is 1 ATM and the temperature is below -78.5 C, then more CO2 is deposited than sublimed (you are on the left side of the “solid-gas” line in the solid area in the phase diagram).
When the pressure of CO2 goes down, the sublimation temperature goes down too. That is the “solid-gas” line in the phase diagram. With 385 ppm CO2 concentration the partial pressure of CO2 is so low that the temperatures needed for deposition to take place do not naturally occur on this planet.
There is no freezing of CO2 below 5.11 ATM because liquid CO2 does not exist below 5.11 ATM. CO2 triple point is -56.6 C and 5.11 ATM. Below 5.11 ATM only solid and gas phases exist.
There is no need to make any experiments about this (unless you want to learn thermodynamics). This has been experimented years ago, that’s why we have the accurate CO2 phase diagram available.

I get impatient when I see >180 comments, but this has been a pretty good thread.
Question, though: has anyone actually seen any CO2 ice at the site in question?

Perhaps an indirect method of sequestering CO2 in the Antarctic: There is a differential solubility in water of the component gases in air that results in the preferential concentration of CO2 and, as is well known, it increases with declining temperature:
http://www.engineeringtoolbox.com/gases-solubility-water-d_1148.html
Some solubilities in g/Kg at 0C, 10C and 20C
Ar: 0.1g; 0.08g; 0.06g
CH4: 0.28g; 0.22g; 0.14
CO2: 3.4g, 2.5g 1.7g
N2: 0.03g; 0.025g;0.02
O2: 0.07g; 0.06g; 0.04g
Look at the enormous solubility of CO2 relative to the other atmospheric gases. “Air” dissolved in water would therefore have a much higher concentration of CO2 to outgas – say if warm water circulated down to the Antarctic, thereby increasing the local atmospheric concentration of CO2. The CO2 could get quite high if a sub sea volcano were to feed in CO2. A breeze over the continent from the sea…… Recall mention in another post of dissolved CO2 in an East African Lake outgassing and killing a number of people. (OT; I’ve mentioned in another post the possibility of a terrible accident if we start sequestering CO2 in underground reservoirs….potential for breach…faults, seepage into a valley…). Perhaps some physical chemists may be able to carry this discussion further.

Moderator:
Last night’s comment about too steep a thermal gradient
really was from me — but from another machine. The
comment seems to have been filtered out. It is still
pertinent, so feel free to include it.
REPLY:AFAIK gone, but I don’t moderate overnight, sorry, feel free to resubmit- Anthony

Absolutely great debate ! A fine example of what has been missing in the climate debate. An open and real time exchange of ideas that reflect primary understandings, but does not exclude experiences or new thinking and data.

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.
is wrong I’d like to point out that
1) It ain’t Friday
2) When it is Friday it’s going to be hard to disprove unless you are actually on site.
So in theory you may have your own conclusion but in actuality the actual proof one way or another is unlikely to ever be published.
Not that I condone tabloid headlines of course.
Oh, and what is this F stuff ? We don’t do polar extent in square furlongs anymore so lets drop the silly old fashioned temp scales.
C or K please, preferably C.
Regards
Andy

All this chatter about phase diagrams but I didn’t see anyone mention the 3D – phase diagram.
http://biomodel.uah.es/Jmol/plots/phase-diagrams/

One other thing Philip.
I have on several occasions posed the question: Why on earth do they have all that ice down in Antarctica and also up in the Arctic ocean where it melts back every year. It is important because when it melts leaving ocean that absorbs sunlight; we lose albedo, and gain near black body absorption.
Well we don’t have tons of ice all over the place in Silicon Valley; yet we have plenty of water around, in the Bay, and off the coast. I think the answer lies in all that sunshine that California is famous for .
It appears that the Arctic, and the Antarctic must be severely deprived of sunlight; and I’ll bet that is why it is so bloody cold in those places. It is NOT cold there because of all of that ice and snow; and your Dome_A graphs prove that; at the coldest times the air is even colder than the ice; so the ice certainly isn’t making things cold; it is there ONLY because it is cold; and it is cold ONLY because THERE’S NOT MUCH SUNLIGHT.
And of course since there is not much sunlight anyway; it matters very little that the arctic ice melts and turns into a black body absorber; there ain’t much of anything to absorb anyway. So the effect of polar albedo is pretty minor in the overall scheme of things.
Climatology seems to get the cart before the horse all the time.
The surface Temperature changes CAUSE atmospheric CO2 changes; NOT the other way round. The polar regions have a lot of ice because it is lacking sunlight and therefore cold; NOT the other way round. You get wispy high clouds at night BECAUSE it is warm and balmy; and no clouds at night BECAUSE it is cold and dry; NOT the other way round.
AlGore gets the correlation; he just doesn’t get the causality.
End of Rant.

“- 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

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?

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 ??

just noted I had a major mis-typing session & kept using 103F instead of 113F

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?