unbekannter Gast



H. Maurer, 2015

Long lasting very deep temperatures bring unexpected phenomena.

Having spent some 7 years on the prairies in Canada (mostly in Calgary) I am reporting here on some phenomena that are well-known locally but unknown to people in many other areas of the world. Note that in the prairie provinces of Canada every winter brings prolonged periods of very low temperatures: The thermometer never shows more than – 30 for, say, 5 weeks.

On sunny days with no wind this is surprisingly easy to endure: I remember outings with two small kids on such days, with some hiking, grilling something over an open fire, and enjoying the snow and the fresh air. Also, I have been stretched out on snow for hours, scarcely moving, waiting for some Canada goose or Ptarmigan to show up for our rifles. With overcast sky and wind, even temperatures of just -20 become hard to bear, however.

Cars are built to withstand deep temperatures. Every car has an oil-heater built in with a cord hanging out of the hood, to plug it in wherever your park: in the parking lots of shopping centers, schools, cinemas, universities, doctors, etc. such electrical outlets are standard. The electricity is always free, and you better not forget to plug in your car or your cold and weak battery has no chance to turn the starter when the oil has become very, very stiff!

If you drive to a mountain cabin with no plug-in, you have only one alternative: you have to take out your battery and take it with you to the hut, placing it close to the fireplace to keep it warm. Like this, the oil will still be very stiff in the morning, but at least your battery has enough power to possibly start the car. If it does not start, you can always hope that some other car starts and you might just use jumper-cables from the battery of the running car to your battery, but more often you don’t bother: The working car will just push you bumper to bumper as long as needed to get yours going. This does scratch the bumpers, but nobody cares: after all these are what bumpers are for, right?, and a car is there for locomotion not for a beauty contest!

When a car is parked at very low temperature something else happens: the tires freeze solid. Since tires in parked position are a bit flat where they sit on the ground, when you start the car you are not starting with four tires that are circles, but are circles with part of the curvature replaced by a straight area. Thus, it feels humpedy-dump like you have a flat in all four tires as you start going. Mind you, after a few hundred meters the tires become elastic again (they do survive this freezing and being knocked into shape again… something that has amazed me a lot).

The first time I heard about the city of Calgary (then less than 200.000 inhabitants, now well over one million!) was in 1961 when there was a report in the section “curiosities” in a daily Austrian newspaper: A man trying to create an ice-rink for his kids was just spraying water on the lawn, slipped, fell down on the ground and froze to the forming ice so rapidly and hard that he could not get up again! Fortunately, someone heard his shouts and rescued him from the predicament. At that time it sounded to me like a well invented story. I had to change my mind. In January 1967 I was standing behind our house in Calgary, spraying water with the hose on the lawn to make an ice rink for my two small children. At 40 below this was an experience: the water had hardly dropped to ground when it turned into ice. I was spraying water for an hour, rather satisfied that within this time I had already created a substantial layer of ice.

It was time to warm up and then finish the job! Suddenly I realized that my shoes were frozen to the ice: I had not watched out, some water had also sprayed on my shoes and I had not moved around. It was annoying! After trying for several minutes it became evident that I would not be able to free my shoes, so the alternative was clear: I had to get out of my shoes and run to the house in socks, getting an axe to recover my shoes. This is when I got scared: I could not untie my shoe laces, they were heavily coated with ice! I could not knock off the ice with my gloved fists and I had no stick or anything to knock the ice off! The attempt to thaw the ice by directly holding the hose with the running water against it just created more ice. I had to shout for help. And my wife might have just saved my life that evening!

Water pipes are buried deep into the ground (about two meters) to avoid that the water freezes in them. One winter, during a particularly long and cold spell, the waterworks sent a memo to everyone, to let the water flow from one tap all the time to avoid freezing. They would send a memo when it would be save to turn off the water. So, for months we did not shut off one faucet in the basement. Spring came, flowers started to come out, no frost overnight any more, nice spring days, young women sitting on green grass in their bikinis, everyone starting to plant vegetables and flowers. When harvesting the first radishes from the vegetable patch in late May it became clear to me that the waterworks had forgotten to inform us that we now could turn off the water in the house. So, I turned it off.

Next morning, there was no water: it had frozen solid in the underground pipes! My call to the waterworks was answered by a deep sigh: “You too!”. They came around and pushed incredible amounts of electricity from a distribution point through the pipes to our house, heating the long and thick pipes (!), enough to remove the ice.

I guess I should have been more careful: the temperature of the soil down to about one meter was already above freezing, but further down it was still much below freezing: In a way the deep temperature was sinking deeper and deeper into the ground! I am a mathematician: with a friend I evaluated some differential equation seeing how dramatic the cold spread slowly downward, independent of how warm it was already at the surface. I should have done those calculations before!

In winter the very cold air outside means that inside buildings the air is very dry. Together with the usually wall to wall carpeting (instead of wooden floors or tile in other parts of the world) one tends to collect quite a bit of static electricity. When touching the handle of a door one tends to get quite unpleasant electrical shocks. One learns fast: Before grabbing the handle one uses three finger to tap-tap-tap the area near the handle, thus apparently getting rid of some of the electrical charge, and only then opening the door. This tap-tap-tap before opening a door becomes such a routine that you always do it. When I moved back to Europe and (without consciously realizing it) I continued to do it. Friends would look flabberghasted at me, not knowing why I was doing it. It took me a long time to get rid of this habit again!

Calgary is located at a big river, the Bow. In some winter, the ice always drifting on the water piles up, blocking the way for further ice, thus creating a more and more massive barrier. If it gets too big, it can lead to dangerous flooding, and these days explosives are used to blow up the such dams of ice when they get too dangerous. But before this happens, there is a spectacle for eyes and ears: as the pressure from additional ice increases, floating ice is catapulted upwards with incredible noise. Those of you who have experienced the break-up of arctic or antarctic ice in spring will know what I am talking about: That this can also happen in a big city is, however, an unusual experience!

Some times the cold can be dangerous even in trivial circumstances. Here is one such case that I experienced myself. When I was graduate student at Calgary in 1962 the IBM 1620 computer, then state of the art equipment, was used so heavily that I often decided to use it during nights. One late evening I went to the campus, then a group of low buildings on the outskirts of the town. (Now, a beautiful campus with the new town completely surrounding it!). I did not dress heavily: the cab would drop me right at the front door of "Science A" building, and would pick me up there again 5 hours later. I arrive at the building, wave to the cab good bye, and I am about to enter the building. At this point I realize I have forgotten my keys! I first try to rouse attention, but nobody seems to be around. I start getting cold. The nearest houses are 15 minutes walk away, in a foot of snow and maybe 30 below and not dressed for such an undertaking I know this will be tough. Eventually, I realize I have no choice: I have to try to reach the next house. Well, I do manage or you would not read this story. I survived, without permanent damage because of frozen limbs or such, but I did have to spend that night in hospital and had I not been in very good physical shape at that time... who knows!

When I first lived in Calgary (in the early 1960-tis) there was one thing I am not sure it is still much in use these days: "Rubbers" they were called. Plastic overshoes to slip in and use when you were outdoors. You would take them off and put them into always available racks as soon as you entered a building or private home, to keep snow and dirt out. There was only one model: so it did not matter if you put on your rubbers, or the ones of someone else, as long as they fitted in size....

Enough stories for now! But there is much more to tell: Like about the Chinook that is the big brother of the warm winds some wintery Alpine value experience once in a while; or that getting gasoline on your skin in low temperatures is very, very dangerous; that European diesel engines would not work in cold winters; that fish caught when ice fishing would survive for hours without water; that roads in Western Canada would not be cleared of snow, traditionally, but you learnt to drive on ice, sliding around corners... lots of fun after some practice; or that there is no date in the calendar that had not snow in Calgary in some year. And that there may not just be a general climate warming, but there is definitely a warming of the local climate, e.g., in Calgary: The heating of buildings for well over one million people is not ignored by nature!