View from outside of Nina and Morgan’s tent ~7 pm. Looks bright and sunny but the wind will slice right through you.
Today we awoke to strong winds once again, as well as quite a bit of snow drift. Here in Antarctica there’s lots of ice and snow but very little moisture, so the snow behaves less like the sticky white stuff that we’re used to in North America and more like sand. Snow particles are blown by the wind until they hit an obstacle (like our tent), and then is deposited in a pile where the windspeed decreases (in front of our door). Jim came by the tent this morning to let us know the plan for the day (a tent day, as you might have guessed) but his morning greeting sounded strangely far away.Turns out our door was completely buried with snow! Thankfully Jim took pity on us and shoveled for us on the outside while I kicked and punched from the inside (the snow, not Jim). At mid morning the windspeed was 25 mph with a temperature of 0 degrees F, but over the course of the day it has deteriorated slightly. In the late afternoon I got a windspeed of 30 mph and a temperature of -2 degrees F, so we’ll see what happens overnight. We’ve had an excellent season, so we’re not yet feeling too antsy about this weather delay. Yet. In addition to being chilly, this weather is also remarkably loud. I was talking to my dad on the satellite phone, and he could hear the wind shaking the tent. I thought I’d give him and you all a view of what that sound can look like by giving you a view of the camp from my tent. You can see the always-important shovel in the foreground and the solar panels keeping us powered and blogging right behind it, along with the poo and science tents in the background. If you look closely, you’ll see some blowing snow in the foreground and something that looks like mist obscuring the tents in the background–that’s the blowing snow that piles up in front of doors and clogs up skidoos. Already the drifts around camp have become significantly enlarged. We likely have some work ahead of us to dig out the campsite once the winds die down. They have to die down at some point, right? While we’re stuck in the tent, we can catch up on a variety of chores, including making water–fun! If you’ve planned ahead and chipped ice before the storm, you can simply reach outside to your ice bucket and grab some large chunks to start melting on your stove. It takes quite a bit of energy to melt ice and turn it into boiling water, so the tent typically gets noticeably colder during this process (see the postscript from rph below). But the result is a stockpile of delicious, hot water that you can keep in thermoses for when you need it. Readers, please take a moment to think about how great it is that you can have water (!) at any time (!!) of any temperature (!!!). Amazeballs.
Making a batch of the finest hand-crafted water made from an old ANSMET family recipe.
–Posted by Nina shivering in a wind-blasted tent, south Miller Range, 12 January 2016
Postscript from rph: Nina’s observation that the tent gets colder (sometimes a lot colder) when you’re melting ice may be counterintuitive to some; and since I’m a teacher and the semester has started, there’s a little lesson in thermodynamics here I thought I’d pass on for those who want it.
To change water from a solid into a liquid requires breaking the relatively rigid bonds that define a crystalline material like ice. Most of us intuitively understand that breaking something rigid takes extra energy, whether we’re talking melting crystals or hitting a brick wall with a hammer. As a result, to melt ice we not only have to add energy to warm the ice degree-by-degree from about -40 deg. C (the icesheet is cold!), we have to add the additional “bond-breaking” energy. That bond-breaking takes roughly 80x more energy than simply warming water a degree, and only happens right when the ice is at 0 deg C; at that temp you keep adding in energy but instead of changing temperature, the H2O just changes from solid to liquid. Once you’ve added all that bond-breaking energy, everything’s liquid and you can start heating it again.
The effect of this is very evident in the tent, even more so nowadays with very efficient stoves and pots with heat-capturing devices on their bottoms (you can see a set of thermal exchange slots on the bottom of the pot in the photo). While the ice is still all cold, there’s enough heat escaping around the ice to warm the tent at least a little; and the pot creaks and groans because parts of it are hot and parts are cold and things keep moving around. But once you’ve gotten close to 0 degrees and the pot is filled with a mix of ice and water (or more accurately, the bottom of the pan is covered with liquid), the groaning stops. Now the pot is absorbing a lot more energy, that bond-breaking energy, 80x more slowly, and with a big, full and efficient pot, very little heat escapes to warm the tent. Vets of our program might note that when we were using crappy old stoves, poorly ventilated tents and cheap tin pots, the effect was less noticeable; but more efficient fuel use, less fire hazards and less carbon monoxide are significant benefits, worth a temporarily chilly tent. And the carbon monoxide probably would have stopped us from noticing it anyway.
Even geekier post-postscript for math geeks: Warming 1 milliliter of water 1 degree takes 1 calorie. Most tents use about 5 l of water, usually boiled, per day, so we’re talking 5000 x 140 calories just to change the water’s temperature from -40 to +100 deg., and then another 80 x 5000 calories to change the water from solid to liquid. So getting a day’s worth of water means giving up over a milliion calories of the stove’s warmth. Note these are thermodynamic calories, not food calories (which are 1000x bigger). But stretching that analogy, that’s the equivalent of skipping half of the meals in a typical US adult diet. It definitely affects your comfort.