What minus 20 degrees feels and looks like

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What minus 20 degrees feels and looks like

Postby Tommydoodle » Tue 08 Jan, 2019 1:46 am

Stupid question I know: sooner or later someone is going to post "cold".

But here's the rub: one of my students asked me today: "if you don't have a thermometer, how can you tell the difference between 0 degrees Celsius, and 20 degrees below zero Celsius?

I thought this was quite an interesting question if you break it into two parts: what does the landscape look like at 20 degrees below zero (in the absence of wind): will the ice and snow somehow look different? Does the light appear different? Do things look different?

Secondly: what does 20 degrees below feel like: on the skin, the face, in the lungs when you breathe in?

FYI my student is writing a short story about someone who gets separated from a group of travellers in 20 below weather. She's looking for authenticity. Bless her.

I don't think I've ever been out in 20 below, so I thought this forum might have some extremophiles that have and might be able to help out.

NB: 20 below in a wind free environment, not a blizzard.

Thanks
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Re: What minus 20 degrees feels and looks like

Postby Hallu » Tue 08 Jan, 2019 1:59 am

I can tell you that it's in the lungs you'll feel it the most, especially if there is no wind. With wind you can say "ok that's *&%$#! cold". But without wind your skin can still be fine. However every breath you take hurts a bit, and a balaclava becomes your friend. Also, without proper shoes, your feet become stiff, hurt, and feel like wood, until they become numb. Again with no proper clothing you start to shiver, your teeth can rattle, etc... Your eyes also feel weird, and you need to blink a lot. And last but not least, your mind is like goo. After a while you can't think properly, you feel a bit clumsy, take stupid decisions, often you can't do simple math. -20 isn't necessary, it can happen at -10. I'm an amateur photographer, and it happens to me a lot when I'm waiting in the cold for sunset or sunrise. When I'm snowshoeing in the cold I'm fine because I'm constantly moving and warming up. But keeping still you can become stupid fairly quickly, like "ok what's this button for again?". Or you can go back to your car coz you forgot a filter or the tripod. Then you get to the car and you forgot what you needed. Hope this helps.
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Re: What minus 20 degrees feels and looks like

Postby Turfa » Tue 08 Jan, 2019 11:59 am

+1 for breathing and eyeballs being the first things to tell you it is properly cold. At 0 neither of these things is noticeable, but at -20 breathing is slightly painful and your eyeballs feel cold.
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Re: What minus 20 degrees feels and looks like

Postby Moondog55 » Tue 08 Jan, 2019 8:01 pm

Snot freezes in your nostrils, frost forms on your eyebrows and moustache from exhaled breath, your nose is constantly dribbling because your body is trying the hydrate the air you breathe as the cold dry air passes over and through the sinus passages and if you/ I take a really deep, hard, fast breath in I get an almost instant Ice cream headache.
The is the transition temperature for me and if not wearing the right boots I lose heat very quickly though the soles of my feet, I can be hot all over but the bottoms of my feet are chilled, it's when I force myself to slow down and do things right the first time because I know I only have the once to do it. But I've never felt in danger because I've taken the time to research and dress well. How I would have coped without the knowledge and training I don't know, probably scared/terrified/ shaky/worried all at the same time
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Re: What minus 20 degrees feels and looks like

Postby Suz » Thu 10 Jan, 2019 10:46 am

I lived in Montreal for a winter and I don't remember experiencing the symptoms above but I do remember really bad pain in my hands from them becoming so cold. Painful to the point where I'd become angry every day after 40 mins walking between home and work. I think I have Raynauds tho :?
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Re: What minus 20 degrees feels and looks like

Postby wayno » Thu 10 Jan, 2019 12:18 pm

Cant remember what temp. but around -20, when you throw boiling water in the air it freezes in the air....
just checked its around -30
from the land of the long white clouds...
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Re: What minus 20 degrees feels and looks like

Postby wildwanderer » Thu 10 Jan, 2019 4:44 pm

I’ve been in -26C in the Yukon.

Its cold. :mrgreen: One thing I noticed was that the cold aggressively seeps into your layers. I was warm for about 5-10 mins, then I started feeling cool and then cold. You feel the cold actually sinking into you through your gear. After 15-20 mins I had to go back inside the hut and warm by the stove for about 10 mins. I was dressed with heavy weight winter gear, balaclava, fur hat etc. Good insulated boots are a must as without you feel the cold radiating though the soles of the boot.

I wasn’t actively exercising, was just slowly wandering around in the night time and waiting for the Northern Lights.

I didn’t experience the painful breath. Maybe this only occurs when exercising? Ive had it before at around -2C on a early morning run in Australia.
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Re: What minus 20 degrees feels and looks like

Postby Tommydoodle » Thu 10 Jan, 2019 11:32 pm

My student thanks you all heartily. She's also asked again do things look different (when there isn't any wind): is the snow 'sparklier' or the sky look different?
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Re: What minus 20 degrees feels and looks like

Postby Moondog55 » Fri 11 Jan, 2019 2:25 am

If the weather is right with clear skys sometimes it seems much clearer and you seem to be able to see very long distances, whether this is an illusion or not I am unsure
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Re: What minus 20 degrees feels and looks like

Postby Gadgetgeek » Fri 11 Jan, 2019 1:14 pm

-20, also known as "slightly chilly' (you know I had to) can start to look different. Frost forms slower and larger at warmer temps, so any frost or snow is going to be more fine grained, although its still "snowflakes" as most people would conceptualize them. Colder, around -30 any snow is much more like sand since there is little water left in the air. Out in the prairie where I grew up there is very little humidity at -20, where as somewhere close to the great lakes will still have massive amounts of humidity a the thermal mass of the lake dumps water into the air. Ice fog, or haze looks different than warm fog, but that could be due to when it occurs. We think of fog as being an early morning or evening thing, where as ice fog can be in the middle of the day. Imagine being inside a photographers white-box. Ice fog can feel very unnatural because you have no depth if its light, something that fog normally has unless its really thick. If there is just a slight haze, in the heat if the sky starts to look dirty, or murky, in the cold it will look watery, pale, you may even see the refraction rings from the sun's light.

Frost in particular will change over time, so if you had a drastic temp shift and the temp went from just over 0 to -20 over a couple days, everything would have thick fuzzy frost, but as time went on that would be slowly sublimated away by the sun, so after some time it would have dissipated, presuming that a wind didn't disturb it. New snow has more of a velvet look, and as it ages it gets more of a gloss, or can become more matte, like sand, depending on how the wind interacts with it, and the day/night temp shifts.

At -20 with no wind there is also not the same sort of convection, so smoke will sit and hang without dissipating as fast. In a forest you'll see it just start to haze around the branches as it doesn't really escape, in an open yard from a chimney it corms more of a column, and as it gets even colder, it might start to settle down towards the ground after cooling. Its also possible to see the thermal layers where the smoke might get trapped in a yard ringed by trees. I've heard stories of people who could tell the temp by looking at smoke coming out of the chimney, but like all tall tales, the thermometer might have been out that window. In general thought air stays cleaner as dust gets stuck to the snow.

Also for reference, -20 for someone who's grown up in it is really not that bad. It was well within the realm of working outside all day without exceptional planning or equipment, about like working outside at +28, obviously you can't be too dumb, but its also not that big of a deal for those conditioned to it. The frostbite limit is around 30 minutes, but we are talking, sitting still, no way to keep warming, and only exposed skin. Activity level matters, not hard to start sweating at -20.

Sound really changes when it gets cold. Sound travels a lot farther as the air gets more dense, but because you don't have the noise of wildlife it gets quieter as well. Some sounds will travel farther than others, its possible to hear say the blade of a saw mill and not the engine or even the wood being cut, just the musical note resonating from the blade. Because you hear the high frequency sounds more things sound "sharper" where as heat and humidity can make things duller and more muffled. This get more extreme the colder it gets. Snow starts to creak, and you can hear much more noise from trees. I've heard that in the right conditions sounds can be heard due to the sound bouncing back down off a thermal layer in the atmosphere, but I don't know I've experienced that. The fact that most of the trees will not have leaves, also changes how things sound.
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What minus 20 degrees feels and looks like

Postby RonK » Fri 11 Jan, 2019 5:43 pm

Having experienced sub-zero temps many times in the Himalaya, my take is that the perceived difference between 0 and -20 is not really very noticeable if the weather is otherwise sunny and windless. In fact I've been badly sunburned in exactly those conditions.
Perception changes rapidly as soon as there is any wind. When writing about such conditions windchill is the important consideration.
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Re: What minus 20 degrees feels and looks like

Postby Hallu » Fri 11 Jan, 2019 6:39 pm

There's no definitive answer about snow or the sky. The snow is fluffy right after a snowfall. It gets harder in the Spring, and cold nights will form a crust, fresh snowfall on this a potential avalanche, wind will changes things too, the amount of snow etc... As far as the light is concerned, well it depends on the country, the latitude, the altitude etc... Higher elevations will have deeper blue skies in general (less atmosphere), and of course the closer you are to the poles the shorter the days in winter and the slower the sun sets/rises.
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Re: What minus 20 degrees feels and looks like

Postby Gadgetgeek » Fri 11 Jan, 2019 7:43 pm

RonK wrote:Having experienced sub-zero temps many times in the Himalaya, my take is that the perceived difference between 0 and -20 is not really very noticeable if the weather is otherwise sunny and windless. In fact I've been badly sunburned in exactly those conditions.
Perception changes rapidly as soon as there is any wind. When writing about such conditions windchill is the important consideration.

I have a buddy back home who is fairly notorious for not realizing how cold it is if he's having fun, just doesn't notice it at all, granted he's a big guy, but I've been out with him for hours before he's realized he's left home with no gloves, hat or jacket in that 0 to -20 range.
Wind chill can be a real shocker, I've had cars go from warm to uncomfortably cold because we turned and were no longer sheltered from the wind, or shut them off and become cold even in the time it takes to get organized to leave the vehicle. But those were high wind -40 days, exceptional conditions. My mom has treated many cases of people with frostbite from high winds because it was "not that cold" but you know how wind can funnel down city streets. When I was little we were not allowed to wear jeans outside in the winter without our insulated overalls or pants. She'd had to remove jeans from frostbite victims almost the same way you do for burns.
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Re: What minus 20 degrees feels and looks like

Postby bernieq » Sun 13 Jan, 2019 1:12 pm

Cold stores are run at -25 (or -18) and fork lift drivers work in them for a couple of hours without issue (in the right gear). The problem is going from warm to -25. Moisture on your nose hair freezes and hurts like hell.

I've been in -40 (ambient) in New Brunswick in January - stupidly cold but not painful to breathe. BTW, is that F or C ? At -40, it's the same !

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Re: What minus 20 degrees feels and looks like

Postby Tommydoodle » Tue 15 Jan, 2019 2:18 am

Excellent everyone: I've passed all of this onto my student. She thanks you all again for this knowledge you have so freely shared.
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Re: What minus 20 degrees feels and looks like

Postby ChrisJHC » Wed 16 Jan, 2019 8:09 am

Here’s a video that will give you a feel for the conditions:

https://m.youtube.com/watch?v=9cDU8MpQ5 ... qquKQdK35e
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Re: What minus 20 degrees feels and looks like

Postby Moondog55 » Mon 04 Feb, 2019 10:24 am

Tommydoodle wrote:Excellent everyone: I've passed all of this onto my student. She thanks you all again for this knowledge you have so freely shared.


Well now we are waiting to read what said student writes.
If she can find an industrial deep freeze somewhere perhaps she could wear a bathing costume and wet herself down and stand in the breeze for a minute or two so she gets a feel of what it might be like to fall through the ice while skating or some such.

EDIT
I thought I should come back and add in one of those semi-obligatory safety warnings.
If you decide that finding a deep freezer and experimenting is worth while you need to have a well dressed companion there to keep an open eye on the participant and a warm etc waiting on the outside. Within reason this can be uncomfortable but not really dangerous in a short time-frame. I've done it quite a few times when working in stinking hot kitchens and walking into the freezer while sweat drenched, sometimes it was actually a pleasant change
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