Lab experiment regarding CO2 “snow” in Antarctica at -113°F (-80.5°C) – not possible

Frozen CO2 at the poles of Mars - but not possible on Earth

A couple of days ago WUWT carried a story, talking about intense cold in Antarctica, carbon dioxide, and the icecap of Mars. This one passage stirred up a significant debate:

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.

It seemed (at the time) a reasonable statement. The freezing point of CO2 is -109.3 degrees Fahrenheit (-78.5 degrees C). There’s been mentions of this supposed phenomenon of CO2 freezing out of the air before on other blogs and websites. One of the best examples was even an entry in the website “ask a scientist” where the question of CO2 freezing out of the air was posed, and the answer from an Argonne National Laboratory scientist seemed to indicate that CO2 could indeed precipitate as a solid from the air if the temperature was low enough at Earth’s South Pole, specifically Vostok Station, which holds the record for the lowest temperature recorded on Earth at −89.2°C (−128.6°F)

Certainly, at least some of the carbon dioxide in the atmosphere at the poles does freeze out during the winter. However, there is not enough frozen out to accumulate to any extent at the present.

David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory

So, it seemed possible. But as WUWT commenters soon pointed out, temperature is only part of the equation needed to deposit CO2 as a solid from the free atmosphere at that temperature.

Soon we were discussing gas laws, phase diagrams, and partial pressures. The debate mainly centered on whether or not this phase diagram for carbon dioxide applied to 1 atmosphere of pressure of pure CO2 versus simply 1 atmosphere of pressure independent of the purity of the gas.

The author of the post, Steven Goddard wrote:

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

The PDF referenced doesn’t translate well to the blog size format, but this less detailed phase diagram for CO2 does fit and was mentioned in comments also:

Since many of us know from experience that with ice, be it water ice or CO2 (dry) ice, that a phase change can occur directly from solid to gas (sublimation). It seemed reasonable to conclude that the reverse could be possible, going from a gas to a solid as long as the temperature was below the “triple point” of CO2 as well as the freezing point at 1ATM.

The freezing point/sublimation point of CO2 at 1ATM is at -78.5C (-109.3F). In the situation described in the forecast for Vostok station, the temperature was forecast to reach below the freezing point for CO2 at -80.5 C (-113F ). It seemed reasonable then to concludes that CO2 would freeze right out of the air, much like frost does from water vapor. Plus we had a statement from a scientist at a National Laboratory saying it was possible also. What’s not to like?

One small detail: partial pressure.

The concentration of CO2 in the free atmosphere is very small. Thus the partial pressure of CO2 in the atmosphere is about 0.0004 atmospheres. But wait there’s more. Vostok station is at a high elevation, 3288 meters above sea level (10,787 feet) and the atmosphere is thinner. Thus the partial pressure of CO2 is even lower.

Commenter George E. Smith summed it up pretty well with this paragraph:

At -78.5 deg C (-109F), that equilibrium occurs at a partial pressure of CO2 of 760 mm Hg, one atmosphere. Below that pressure, there isn’t enough abundance of CO2 molecules in the vapor phase for collisions with the solid surface to occur at a fast enough rate to make up for the ones that escaped; so the solid CO2; dry ice, will continue to sublimate.

Basically, there are so few CO2 molecules in the free atmosphere, sublimation rules over deposition as a solid. Yes some CO2 may deposit on a surface at at -80.5 C (-113F ), but it would quickly sublimate back into the free atmosphere, and thus accumulation would not occur.

Meanwhile WUWT reader Ric Werme had written to Dr. David Cook of Argonne National Lab to ask about his original opinion he wrote for “ask a scientist” web site. Ric reports he responded with this:

Ric,

You are correct. In my attempts at being simplistic I made a mistake in my answer to “Freezing CO2″ on the Ask-A-Scientist page. -57 C is the boiling point of CO2. The freezing point of CO2 at atmospheric pressure is -78.5 C (-109.3 F). If the temperature reaches -113 F at Vostok, Antarctica, some carbon dioxide might freeze out of the air, assuming that the carbon dioxide vapor pressure drops to its saturation vapor pressure.

The vapor pressure must reach the saturation vapor pressure for dew or frost to form. This happens at the dew point or frost point temperature, which is dependent on atmospheric pressure and the absolute amount of vapor in the air. As atmospheric temperature increases, the dew/frost point temperature increases. As atmospheric pressure increases, the vapor pressure increases. At very low temperatures, the dew/frost point temperature is very low.

When the temperature of the surface (whether grass or a car window) is below freezing, frost will usually form instead of dew, although water can be super-cooled and not produce dew, fog, or clouds in some cases. Surfaces on the Earth cool off sooner than the air, so dew/frost will normally form on them before fog (water or ice) forms in the air.

The temperature being at “freezing” or below does not imply that frost will form on surfaces or in the air. The vapor pressure must be high enough (saturation vapor pressure) and the temperature low enough (the frost point temperature) for frost to form.

So it seems, Dr. Cook (and our own Steve Goddard) made the basic and simple error of not taking vapor pressure into account. Given our human experience with the everyday freezing of water, we don’t often think about it. I didn’t catch it either initially, nor did some WUWT commenters.

It does demonstrate though, how little CO2 there is in our atmosphere, we can’t even precipitate it to solid under any natural condition of earth.

But, even with the debate apparently settled, the CO2 freezing question was still all in the realm of opinions and phase diagrams. Some people really wanted to see some empirical proof. Some thoughts on experiments were tossed about.

Enter WUWT reader Dr. Thomas Thatcher of the University of Rochester who had not only an idea for an experiment, but the means with which to carry it out. He had a lab freezer which would “maintains -80˚C (-112˚F) in my lab, and it can be set as low as -86˚C (-122˚F).”.

He proposed that he could use that freezer to do a test with dry ice:

The argument, as far as I can tell, is that at the atmospheric partial pressure of CO2, dry ice at -113F will sublimate faster than it forms (which may be different than how a pure CO2 atmosphere would behave). I am in a position to test this, as described above.

…

Based on the arguments presented here, the two postulated outcomes are,
1) significant loss of mass, as the sublimation rate exceeds the deposition rate
2) no change, or negligible gain in mass.

(I suspect that any gain in mass will evaporate on the short walk from the freezer to the balance.)

It’s admittedly an imperfect experiment. But I expect the outcome will be rather obvious; the dry ice will be gone in the morning. We’ll see.

He conducted his experiment overnight between Thursday and Friday, and writes:

The freezer is a VWR brand ultralow temperature upright freezer, similar to models shown here.
http://www.vwrsp.com/catalog/product/index.cgi?catalog_number=14230-120&inE=1&highlight=14230-120

It is set to -86C, the temperature typically rises 1-3C when opened, and recovers in about 30 minutes. (Factory temperature calibration was NIST-traceable but it has not been recalibrated since it was installed here.) The samples were loaded at 4:30 pm and removed at 9:30 am, so the freezer will have been largely undisturbed during that time.

The interior is mostly filled with stainless steel racks that hold cardboard boxes for storing biological samples. I placed the test samples in two boxes on the bottom shelf at the rear of the freezer, the coldest zone and closest to the temperature probe.

One sample was placed in an open box with extra holes cut to allow air circulation. The other sample was placed in small zip top plastic bag inside a cardboard box. The samples were weighed by difference before being placed in the freezer and after removal in the morning. Additional weighings were taken to estimate the amount of sublimation during the weighing procedure and the amount of water that might condense on the boxes, but these amounts proved insignificant next to the overall results.

The samples were placed in the freezer at 4:30pm (reading -82C) and removed at 10:00am (reading -83C).

Open container, start weight 36.5g dry ice, end weight 0g, amount sublimated 100%.
Zip-top bag, start weight 27.6g dry ice, end weight 25.3g, amount sublimated 8.3%

Proving, I think, that CO2 will freeze and remain frozen at below -78.5C if the partial pressure of CO2 is near 1 ATM, but the CO2 will rapidly sublimate is the partial pressure of CO2 is near atmospheric normal.

And he concludes:

Bottom line, 40g of dry ice placed in an open container at -82C completely sublimated overnight, while 27g of dry ice placed in a zip top bag retained 90% of its mass. This proves two things, first, that the temperature of the freezer did not exceed -78.5C for any appreciable period of time, and second that yes indeed, the partial pressure of CO2 is the key to the problem.

Best of all, he sent photos of the experiment he conducted:

Interior of the freezer showing sample box racks

The placement of the two sample boxes for the CO2 sublimation experiment

The two sample boxes with dry ice of equal weights, enclosed on the left, open on the right, just before they were placed into the freezer for the night.

The sample boxes immediately after removal the next morning.

With the plastic bag removed, showing the leftmost sample still about 90% intact.

Thanks to everyone who participated in the debate, including Ric Werme for his correspondence help and especially Tom Thatcher for conducting the experiment and taking photos.

We all learned something, we had a little fun, some online yelling occurred, and some egos were bruised. Overall though it was worthwhile that this myth of “CO2 snow at Vostok station” was finally put to rest.

Snow in Saudi Arabia in May?

From the Saudi Gazette

In one of the rare occasions, Saudis enjoy the snowfall in Al-Baha city south-west of Riyadh, Tuesday. Torrential rains pouring down on Al-Baha accompanied by gusty winds were accompanied by snow capping the mountains and covering the valley areas and the forests of Al-Zaraeb and Khayrah.

The last report we had like this in mid January said that the snow and cold was the “worst in 30 years“. In January, snow isn’t unexpected in Saudi Arabia, it has happened before. But in May?

While the report says “snow”, the possibility exists that it could also be small hail from thunderstorms.

Looks like it is warming up fast though. The forecast calls for 93 degrees. Just remember, weather is not climate.

Snowiest Winter Ever Recorded in North Dakota

A snowmobiler negotiates the streets of Crosby, North Dakota. Photograph courtesy of the Crosby Journal.

Guest Post by Harold Ambler

Snow, wind, and cold have assaulted North Dakota yet again in the past 24 hours. In Bismarck Friday morning the temperature was 12 below zero with a new inch or two of snow expected following Thursday’s more significant storm.

According to USA Today, snow in the southern part of the state was bad enough Thursday that snowplow operators were pulling off the road, blinded by the whiteout conditions. A foot of snow was common in the heaviest band.

The National Weather Service predicts a high temperature of 3 degrees Fahrenheit Friday in Bismarck, as well as additional snow. As of Thursday, three-quarters of the state’s roads were still snow-covered, in whole or in part, from the storm that just ended the day before.

Howling winds and copious snow have combined to leave austere scenes like this in Cavalier County, North Dakota. Photograph courtesy of the ND Department of Emergency Services.

More than once during the winter, the Department of Transportation has issued a no-travel advisory, most recently on February 10.

Cecily Fong, spokeswoman for the state’s Department of Emergency Services, said that the winter got off to a bad start on November 4. “That first storm was definitely a blizzard with blowing and drifting snow,” she said. Since then, according to Fong, several counties have seen more than 400 percent of normal snowfall.

December was a record breaker for Bismarck, as it was at many other locations around the state. In Bismarck, the total for the month was 33.3 inches, the greatest amount ever received in a single month.

Those were early days, it turned out. Frequent storms, followed by howling northwest winds and record-breaking cold, have made it a winter to remember. On January 15, the morning low at the Bismarck airport was 44 below zero, the coldest ever for the date, and one degree shy of the all-time coldest reading for a state known to be less than balmy.

By the end of January, many counties had more than 400 percent of normal snow totals on the ground, and Governor John Hoeven had declared a state of emergency.

“There has been a repeated pattern,” said Fong, ”where the county will come and plow a road and then two days later, without any additional snow, the road becomes impassable again.” Relatively speaking, the people in Bismarck have gotten off light. Divide County, in the state’s northwest corner, has received 500 percent of normal snowfall.

Steve Andrist, who has lived most of his life in Divide county and is the publisher of the weekly Crosby Journal, commended the street department. “There has never been more than a day or a day and a half where the roads were

impassable,” he said.

Roads that were cleared once, and twice, have needed to be cleared a third time in various locations throughout the state. Photograph courtesy of the ND Department of Emergency Services.

After a lifetime living so near the Canadian border, did the last few months really amount to anything? “This winter got my attention,” he said. “The thing that’s different about this one is the volume of snow. It’s so much more than we anticipated. As far as snow and moving it, and moving it again, and having to move it again a third time, this has been very unusual.”

On February 19, the governor asked the federal government to provide emergency assistance for snow removal. “We’ve got roads that aren’t being plowed,” Fong said, “just because the funds aren’t available to do it.”

Although the spring melt is weeks away, Fong said that flooding is already a concern. “We don’t know where, and we don’t know when, but we’re keeping our eyes on it.”

Collapse of Ice Sheet would Shift the Rotation Axis of Earth

Geophysicists from the University of Toronto in Canada say that it is the coastlines of North America and the nations in the southern Indian Ocean in particular that face the greatest threats from sea level rises if there is a complete collapse of the West Antarctica Ice Sheet, according to their recent study.

The West Antarctic Ice Sheet.

If the West Antarctic Ice Sheet collapses, the rise in sea levels around many coastal regions will be as much as 25 per cent more than expected, for a total of between six and seven metres if the whole ice sheet melts,” says Jerry Mitrovica, a geophysicist.

Why is that?

1. If the West Antarctic Ice Sheet collapses, sea level will fall close to the Antarctic and will rise much more than the expected estimate in the northern hemisphere because when an ice sheet melts, its gravitational pull on the ocean is reduced and water moves away from it.

2. If the ice sheet collapses the depression (hole) in the Antarctic bedrock that sits under the ice sheet will fill with water. But, as the ice disappears, the hole will shrink as the region rebounds from the loss of ice, which will force some of the water out into the ocean.

3. The collapse of the ice sheet will cause the earth's rotation axis to shift 500 meters from its present condition, which will move water from the southern Atlantic and Pacific oceans northward toward North America and into the southern Indian Ocean.

There is still some question as to how much ice would actually disappear if the whole sheet collapses, but even still, the researchers state that the sea-level rise that would occur at many populated coastal sites would be much larger than one would estimate by simply distributing the meltwater evenly.

There is a link to an illustration of the process at the bottom of the University of Toronto press release.

Snow caused by Global Warming

As many people may have commented over the past few days - this snow isn’t what they were expecting from climate change!

Before you start worrying that maybe global warming is just a tax raising excise, the word is that this is exactly what the scientists were expecting!

From today’s Telegraph, the Met Office say that:

“As for snowfall that could actually increase in the short term because of global warming. We have all heard the expression ‘too cold to snow’ and we have always expected precipitation to increase.

However, there was this warning from another source:

“Just as the wet summer of 2007 or recent heat waves cannot be attributed to global warming nor can this cold snap,” said Bob Ward, spokesman for the Grantham Research Institute for Climate Change at London School of Economics.

This is neatly summarised here:

So there you have it from the horse’s mouth (or backside). If it is hot, its global warming, if it’s wet, its global warming, and if it’s cold, it’s global warming. And if it snows, it’s definitely global warming.

You might like to know how to apply for funding for an environment based project. The link points to the rules you need to know for projects running through to 2013.

Heaviest Snow in 18 Years Brings Much of Europe to a Halt

Feb. 2: Commuters walk over the Millenium Bridge to St Paul's Cathedral in London.

The British capital ground to a halt on Monday after the worst snowstorm in 18 years caused hundreds of flight cancellations and virtually shut down public transportation.

Shops, schools and courts shut down and long trails of commuters trudged through the streets, looking for scarce taxis or ways to work after more than four inches of snow fell overnight.

"We're not in Russia here," said Guy Pitt, a Transport for London spokesman. "We don't have an infrastructure built for constant snow."

Heathrow closed one of its two runways and reported more than 650 cancellations. Major delays and cancellations were also reported at London's other major airports at Gatwick, Luton and Stansted. London's City Airport was closed.

An Airbus 330 coming from Cyprus slid off the taxiway at Heathrow with 104 passengers on board. Cyprus Airways spokesman Kyriakos Kyriakou said there were no injuries or damage. No other incidents were reported.

There were massive traffic jams on many highways near London.

The Met Office, the country's national weather service, said it expected another four inches Monday afternoon.

"We are doing everything in our power to ensure that the services — road, rail and airports — are open as quickly as possible and we are continuously monitoring this throughout the day," said Prime Minister Gordon Brown.

London Mayor Boris Johnson said the city lacked snowplows.

"You can grit and you can salt it but the snow comes down again," he said. "You can make an investment ... in snowplows for London and then not use them for a couple of decades."

Johnson said many buses couldn't be sent out because "if they skid they become a lethal weapon."

London's subway network was hit hard because much of the system is above ground. Of some 12 lines, only the Victoria Line was unaffected.

After waiting in vain for an Underground train to arrive, office worker Caroline Samuel, 36, decided to retreat.

"There's no point in going to work today," she said. "I'm going home."

Many of the tracks were covered in snow or ice and some transport workers themselves struggled to get in to work.

Heavy snowfall in France also disrupted traffic and caused delays at Charles de Gaulle airport in Paris.

Southeast England was hardest hit with up to 10 inches reported in some areas

Met Office Report Card at the 2/3 Mark

The UK Met Office forecast last Autumn “the coming winter suggests it is, once again, likely to be milder than average. ” We have now passed the 2/3 mark of the meteorological winter, and it is time for another report card to send home. Yesterday’s press release was titled “Wintry start to February” which stated “So far, the UK winter has been the coldest for over a decade” and “Met Office forecasters expect the cold theme to the weather to continue well into next week with the chance of further snow.”

The UK is expecting the heaviest snow in about 20 years tomorrow. “Snow and freezing weather threaten to shut down Britain Arctic blizzards are set to cause a national shutdown on Monday as forecasters warn of the most widespread snowfall for almost 20 years.” “Now is the time you’d expect to see the daffodils coming out but we’re not expecting them for two or three weeks at best if it warms up.“

So why is this important? Climate is not weather, after all. The Met Office is one of the most vocal advocates of human induced global warming, and they have gotten into a consistent pattern of warm seasonal forecasts which seemingly fall in line with that belief system. Is it possible that their forecasts are unduly influenced by preconceived notions about the climate? It is worth remembering that London had it’s first October snow in 70 years this past autumn.

Or perhaps they know exactly what they are doing, and are just having a several year run of extremely bad luck with their long term forecasting.

Snow falls in the United Arab Emirates

Yes more anecdotal evidence of a colder winter in the northern hemisphere. This is the second time in 5 years. A USATODAY story says it was “the first time ever” in 2004. Even the BBC reported it. There seems to be some confusion on the precendence between news organizations. In the 2004 stories, USATODAY says “first time ever” while BBC says “every 20 to 30 years”. I would tend to believe the Abu Dhabi local newspaper (over the BBC) who now says “second time in recorded history” in their story below. - Anthony

This is the frozen north … of the UAE

by Anna Zacharias of The National, in Abu Dhabi

Snow settles on the Jebel Jais mountain in Ras al Khaimah yesterday. Courtesy of Ras al Khaimah government

RAS AL KHAIMAH // Snow covered the Jebel Jais area for only the second time in recorded history yesterday.

So rare was the event that one lifelong resident said the local dialect had no word for it.

According to the RAK Government, temperatures on Jebel Jais dropped to -3°C on Friday night. On Saturday, the area had reached 1°C.

Major Saeed Rashid al Yamahi, a helicopter pilot and the manager of the Air Wing of RAK Police, said the snow covered an area of five kilometres and was 10cm deep.

“The sight up there this morning was totally unbelievable, with the snow-capped mountain and the entire area covered with fresh, dazzling white snow,” Major al Yamahi said.

“The snowfall started at 3pm Friday, and heavy snowing began at 8pm and continued till midnight, covering the entire area in a thick blanket of snow. Much of the snow was still there even when we flew back from the mountain this afternoon. It is still freezing cold up there and there are chances that it might snow again tonight.”

Aisha al Hebsy, a woman in her 50s who has lived in the mountains near Jebel Jais all her life, said snowfall in the area was so unheard of the local dialect does not even have a word for it. Hail is known as bared, which literally translates as cold. “Twenty years ago we had lots of hail,” said Ms al Hebsy. “Last night was like this. At four in the morning we came out and the ground was white.”

Jebel Jais was dusted in snow on Dec 28, 2004, the first snowfall in living memory for Ras al Khaimah residents.

“I had flown there in 2004 when it snowed, but this time it was much bigger and the snowing lasted longer as well,” said Major al Yamahi.

At the base of the mountains, residents also reported severe hail on Friday night. “We had hail. Last night was very cold, but there can only be snow on Jebel Jais because it’s the tallest,” said Fatima al Ali, 30, a resident of a village beneath the mountains.

In Ras al Khaimah City, 25km from Jebel Jais, sheet lightning and thunder shook houses.

Main roads from Qusaidat to Nakheel were still badly flooded on Saturday, while temperatures at the RAK International Airport fluctuated between 10 and 22°C.

M Varghese, an observer at the RAK Airport Meteorological Office, told of the storms that hit the emirate on Friday night.

“We had thunderstorms with rain for more than 12 hours and we had around 18mm rain,” Mr Varghese said. “The rain, along with the cold easterly winds and low-lying clouds, could have bought the temperatures further down on the mountains.”

Giorgio Alessio, a meteorologist at the Dubai meteorology office, said: “In thunderstorms, the rain comes down very rapidly from higher levels, and the rain that usually forms can reach the ground in some places as snow. In the next few days the weather regime is completely different and will return to normal for the season, with a maximum temperature of 23°C or 24°C.

“The night might cool down in the desert below 10°C. There is variability in the weather from year to year but it hasn’t shown a trend in getting colder or getting warmer.”

The RAK Government plans to transform the 1,740m Jebel Jais into the UAE’s first outdoor ski resort, using Australian technology that will allow tourists to ski in temperatures up to 35°C.

Abu Dhabi and Dubai also had heavy rain on Friday night.