Snow day!

Everything is truly covered. It is like not a blanket. This is covered in a quilt of snow. It is fluffy and white and charming and cold.

“Oh, it is so windy. You hear that? Alright, let's go. If you weeks ago I had an extremely nice time, wander around the streets of Brooklyn and Prospect Park and talking to people about the snow.”

I can say this park, it is beautiful. It has a lot of trees and all of the trees are really snowy. I can see a lot of snowman. There is a huge snowman over there. I don't know how to say it in feet, but I can say it at least 160 cm.

We realized this morning that this was the best snowman making snow that I have ever seen and so we made this snowman this morning. Now we are back to give it a personality.

How about some of that? Help. Well, we are already built a snowman and we are all left in the park, so now we are going to go get some hot cocoa. I am wearing my cross-country skis from high school. How are you fitting the cross-country skis in your New York apartment? I talked to people with lots of thoughts on snow. I love working out. I love shoveling it. I cross-country skis. I just love it.

“I love it, except a month from now and we still have it. Once it gets disgusting like the last snow did, then I'm over it, but I like this snow for right now.”

But I do love it from a distance. And I also ask people if they had questions about snow. Well, I know that it makes things very quiet because it absorbs sound, but I don't understand. I guess I don't know the science behind why. I did it here. I'm not sure if it's true that like every snow flick is different. I guess one question would be sometimes when snow falls, like you can't really make snowballs out of it. And then sometimes it's perfect like this where you can, you know, you can grab it and make a snowball.

Yeah, just kind of what determines that because this feels like a totally different ballgame. So not everyone had questions for me. Not really, I kind of like not knowing, like not knowing how things, yeah, you know what I mean. Okay, great, I'll go home. I did get enough questions that I decided to call up a snow scientist in search of some answers. So I am Bert Pinkerton and today I'm a show. I'm talking to Jessica Lundquist. She's a professor of civil and environmental engineering and she's going to answer a whole bunch of questions about snow for us.

Of course, this is unexplainable though. So a little later in the show, she's also going to tell us some things about snow that she does not yet know and is still trying to figure out. All right, well, I have a bunch of questions for you as are as our resident snow expert. Let's go.

So the first question I got from a few people is actually about the shape of snow flakes.

“How does the design come about? Like, does there anything that makes it have a different shape, the snowflake? Why are snowflakes all different shapes?”

So snowflakes will form around a tiny speck of dust called a condensation nuclei. Okay, but now it can grow in different ways. So you can grow out to make what we call a dendrite shape. So that's your postcard snowflake, but it could also grow down, right? So you can also get a column, which one of these you get will depend actually on the temperature and water vapor carnage. Actually, on the temperature and water vapor content in the atmosphere where the snowflake is being formed, depending on the conditions in the atmosphere, it will grow in a certain way.

It's often like growing differently throughout its lifetime. And then as to fall from that cloud down to where we are at surface and it will often like hit different snowflakes and then they can aggregate and you can get these sort of messy big things.

“Wait, so what you're saying to me is like the snowflakes shape is like a record of the life it's lived almost like where it's been.”

Yes, so it's telling you about where it's been in the cloud and what it's falling through and whether it hit another snowflake and how it grew. And if you really want to know about snowflakes, I recommend checking out Ken Lieber to grow some in his lab at Caltech.

He can make designer snowflakes every day I learned about a job that I wish I had.

Okay, so the answer to this first question of sort of like why is every snowflake different is like every snowflake has its own little individual path through the atmosphere that shapes how it grows and then also go check out this guys designers snowflake lab. Yes, question two is I got a question kind of about not how it looks but how it sounds so one of the people I met did sort of like an ASMR demonstration of the snow crunching. And then was asking like why does it crunch like that so we've talked about the snow snowflakes history in the atmosphere, right, but then the snow also falls on the ground and has history on the ground.

So you're snowflakes started accumulating on the ground and you have all these, you know, little individual snowflakes that fall on top of each other and they have air in between them. It's not ice, it's a pile of little snow crystals with air in between it.

“Like a fluffy pillow on those the way that your your pillow is like a bunch of others except this is cooler than feathers because snow is always close to its melting point.”

So if you think about some arterial science, if you have like metal and you heat it up so you can weld it and center it if you get your metal really close to its melting point you can like make two points of metal actually attached to each other. So snowflakes will do something we call centering so you also center things with metal but snow will center by itself just sitting there so your snowflakes fell down. They made you know kind of like your feather pillow with air inside and then your little crystal start attaching themselves to each other.

So now you have this matrix of snowflakes that are attached to each other. And then underneath it they have air you could also have right at the surface it might melt and rephrase a little bit so they'll often be you know attached at surface with air underneath. Now crunchy sound you're breaking that oh you're breaking the connections that they formed yeah.

But it's only sometimes you're snow won't always make a crunching noise okay.

“So basically like because snow is slightly melted almost but it it's has the power to stick together it's forming all these sort of fragile.”

Bridges yes and when you crunch it you're just demolishing a lot of bridges all the same time. Great another sound question this is question three why does snow absorb sound. Okay and this it doesn't always do that either so one thing is no so like several different let's know when the ground is also all different. So sometimes it might make a crunching sound and sometimes it might absorb sound so when it most absorb sound is right after new snowfall.

So it hasn't yet a time to make all these sintering connections you just have a whole bunch of little snowflakes.

Just loosely lying at surface so think of kind of like your feather pillow not yet attached but lots of air in between it. So the sound gets kind of muffled by going into all those air pockets in the snow and doesn't get reflected back to your ear so it ends up sort of being a sound absorber. Because it's just loosely connected a whole bunch of air pockets delightful. Okay so then I got a lot of questions about why the snow is the way that it is. So people were talking about sort of like the texture of the snow in this storm versus the one two weeks ago.

It seems like thicker and stickier and like the fluffiness what makes it so fluffy. One person got really descriptive. It's like AI snow. What do you mean? Like I feel like it was 3D printed. Yeah.

It's like tempered pedics. But it was apparently like better for snowballs, better for snow building. Yes. And people wanted to know like what was going on there essentially like physically chemically whatever to make Different snows after different storms.

Yes. So again, we took out the history, right? It starts with their falling through the atmosphere. They fell through different answers.

Snow crystals grow differently and they also have different amounts of liquid water inside of them.

So if you get a colder storm, you have a lot less liquid water and you end up with your dry snow. It won't make a snowball, right? So as you get warmer and you get the biggest change above negative 3°C.

“So as you get between, again, when we talked about snow being really close to its melting point, right?”

So snow is melted points at about 0°C. And as you get really close to that, you actually get more molecules that actually are liquid. And that makes it really sticky. You can build good snowballs with warmer snow. One person asked how it accumulates on surfaces. And so specifically, we were talking about tree branches. And then I was thinking about wires.

And I was curious if there's any interesting physics or whatever going on, structurally there.

So there are actually amazing studies done both in Japan and in Switzerland.

Or they put out all these boards of different widths and different sizes. And then they just measured how much snow accumulated on all of them. The pictures in their papers are really cool. They also did studies where they tried to see how tall could you stack.

“So what was angle of repose, which is the stack of snow?”

So these are questions that lots of people have. Maybe not lots of people, but it definitely been studied quite a bit. It gave us back to some of the things we talked about before. So how much snow you can stack up actually depends on the temperature of the snow.

So again, we got back to that snow being really close to its melting point.

Particularly if you have a warmer snow storm, right? And the snowflakes can center and stick to each other. So they will actually attach themselves to each other. Also the stickiness per se if snow goes up. Usually between negative free degree C and zero degree C.

And if you think about like little bits of it will like melt to be liquid and then re-freeze again. But it will sort of freeze itself onto your tree branches and your different things. And then it will attach itself by centering to each other. And so it's and stack up amazingly. Wow, okay, I'm learning a lot.

Unrelated to structure of things. One person asked what the benefits of snow are for the environment. So like for trees or for parks, etc. No insulates things really well.

“Just like in your house the insulation is you know a lot of pockets of air in between two walls, right?”

Your snow builds up with a lot of trapped pockets of air that insulate the temperature. So it turns out that in most most cold regions the temperature at the top of the snow pack above the snow is significantly colder than the temperature at the basis of snow. So if you go to the Arctic, it's often like more than 20 degrees Celsius different between the top and the bottom of the snow. So it'll be you know like can get negative 40 in the air and if you're under the snow, you're super warm. So if you're out in a really cold storm, you can dig yourself snow for it.

Bear yourself under the snow, you'll be warmer, right? So a lot of animals live under the snow. Some hibernate under the snow. Some many build their dens under the snow, right? It's a warm safe place through the winter.

And is it is it just animals or are there other things kind of taking advantage of this warm blanket effect? Plants, microbes, you know things in the soil that are using that same insulation to survive like plants with shallow roots in cold regions. So often I've root damage if there's not a good snow year. It's kind of counterintuitive that it often in years with less snow, it's colder for a lot of plants and animals because they can't hide under that blanket. So clearly there is a lot about snow that's no mystery to Jessica.

But there are some things, Jessica does not know about snow. So after the break, it's no mysteries with Jessica. [music playing] [music playing] [music playing]

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My mom always had peanut butter and brown sugar. She was not a syrup person.

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I mean, podcasts. [music playing] All schools are officially closed for a snow day. [music playing] All right, Jessica Lundquist was patiently answering all our questions about snow.

“But I also had some questions about Jessica. Like, what got her into studying snow to begin with?”

She told me she grew up in California, and her favorite thing to do was to go to Yosemite. I just like going in the mountains and going hiking, and I went in the summer, which, you know, generally there's no snow. But then quickly realized that the amount of water in the river that I like to jump in and go swimming, was completely related to the amount of snow in the mountains. So you were like, I'm going to spend a great deal of my career studying this question.

No, of course not. I said I want to be a park ranger and just go hiking in the mountains. She did wind up becoming a researcher though, not a park ranger. And she began tackling this big question related to snow. How much snow is there actually in the mountains? It turns out that on the west coast of U.S., snowmout can be an important source of water.

So basically, in the western U.S., we don't have enough water for all the things we want to use water for. There's a lot of people living in the west. There's a lot of crops grown in the west. All of these lead water to grow. And basically, the water is allocated to people through this water-right system. So in terms of what is the value of snow, it's like three reservoirs, right?

It's storing that water in the winter for the summer.

So people always want to know how much water exactly do we have in the snowpack.

Because it's actually so dry out here that people will be told, don't plant, right? We can't give you water this year. You can't plant your crops. You need to furlough your fields and you do something else. So a lot of what I try to do is figure out how much snow there is in the mountains at any given point, time.

“And if the job is often to predict the future, I think, can you predict how much water will have in the future?”

But this is easier said than done, because it's tricky to measure how much snow there is in the mountains. A lot of snow falls in places that don't have roads that don't have infrastructure. There are ruggeds to trade without a lot of access. A lot of it fell in place you can't go. But it's extremely variable. If you put out a measurement site, so the national resource conservation service for NRCS has something that's called a snow pillow. So it's basically you have like two metal plates. You fill it with any freeze. You put it right on surface of the ground and you bury it slightly so bears can't find it.

There's no falls on it, squeezes the water or the antifreeze, which then creates a pressure gradient. And it tells you how much, what is the weight of the snow resting on the snow pillow. So basically that weight tells you what we call the snow water equivalent, like for basically for water resources. If all that snow melts, how much water do we get out of it? This is the snow water equivalent. Or you may hurt the term sweet. That's WEs. The water equivalent.

I have not heard the term sweet, but I like the term sweet quite a bit. Okay. That sounds great. That sounds like we have a measurement. Fantastic. Exactly. But if you walk can't step to the left, you're going to measure something completely different. Oh, right. Okay. This is somewhat less sweet. The same problem exists for other measurements, and satellite images can be tricky.

And so Jessica and researchers like her may never be able to work out at a perfect measurement of the snow in the mountains on a new good near.

And then seeing how much water they're ends up being in the following warm season. And that means that they can say, you know, one of our measurements look like this in these various spots. There will probably be this amount of water.

And this is on probably, though, because the predictions are not always as neat and tidy as this makes it sound.

“So that's why I'm still employed. So the number of things can trip people up.”

One thing we did recently, so based on the Colorado Colorado River provides water for what seven different states who all argue about much water they get is often in the news is not having enough water. And what they've noticed is since 2000, the amount of water in the river was less than what was no predicted. And 2021 was a particularly bad year. They thought, from the snow pack, it was kind of close to average and then it delivered way less stream flow than they thought.

And so, you know, then people aren't prepared because they bought their seeds to plant and then they get the water cut off and they lose their crops.

And so it's for some people, economic disaster to get this forecast wrong. Jessica says the reason these forecasts were wrong was that it had stopped raining as much in the spring in Colorado. And so if it is super dry and warm in the spring after April after they take that survey, it turns out that the plants wake up early. And it's sunny and they say, okay, I'm going to start using water to grow as a plant. They start transpiring evaporating and a lot of that water goes back to the atmosphere instead of in the street.

So the plants before it can even get to the stream, the plants near the snow are like vacuuming it up in a variety of ways. Yeah, is climate change affecting your predictions at all? So basically climate change warmer temperatures the biggest impact is that more precipitation falls as rain instead of snow. So now in terms of predictability, rain is fast, right? When it rains it runs off right away. So the snowpack, what it does is like it actually allows us.

But this kind of year and it's crucial April for snow surveys to say, this is how much water is going to be in the rivers in the summer.

Actually, I have no idea how much it's going to rain in May or June in the western US right now, like that we can't forecast, right? And without the snow, it's that kind of guess of how much will it rain in the future that we have to rely on. So so snow itself by virtue of just storing the water on the hillside gives you a lot of predictability, then we don't have when it falls as rain instead of snow.

“Fascinating. All right, easy question to end. Is there a snow that you would revisit from your life that you'd encountered?”

Yes, so I did a project. We were saying snow out in Gothic Colorado, which sort of I pressed it to you, middle and nowhere, Colorado Rockies. You're staying in this old abandoned mining town that is now a biological research station that you can only access by skiing in. So we're skiing in and we're staying in this old mining town. And every day we are cross country skiing out to our measurement sites to dig in the snow and measure things. So we're the only people out there, and it's like snowing really lightly, and I was I was a friend of the line of everybody cutting out just sort of cross-cursor skiing on our route.

And then all of a sudden right in front of me, I disturbed a bunch of tarmagan that were hiding under the snow. So the tarmagan, especially when it's really light fluffy snow, they will like bury themselves in the snow. But as I went by them I scared them. So all of a sudden the snow erupted and a whole walk of white birds blew out of the snow like in front of me and all around me. It was like the snow erupted birds. I mean, it was beautiful. That's so magic.

“I keep looking online like has someone video take this. I can't find a like YouTube recording of like tarmagan erupting from snow. If you ever find one, you have to send me.”

Okay, this is perfect. We had we brought we came to you with questions that people had and and now you are leaving our audience with a question that you have, which is does anyone have videos. I'm sorry, I'm just ranting from the snow. Well, I'll let you know if anyone sends us any. Thank you.

In this episode was produced by me, Bird Brinkerton. It was edited by Joanna Solitarov.

“There's also her idea to send me walking through the cold and snow. It's one lovely person I spoke to put it.”

I'm going to come out and do some of this. I'll let her know. Christian Ayala to the mixing and the sound design. No, I'm Hassan Feld does our music. Melissa Hirsch checks our facts Jorge just Meredith Hadnott, Julia Lungoria, Sally Helm and Amy Vadula are the fact that some macax in Japan have been recorded making balls of snow that they rolled on hills. Thanks so much to everyone who gave me their questions and their thoughts on snow. I really appreciate you all. And if you have videos of Tom again, bursting from snow, please send them to [email protected].

“If you have videos of any birds bursting from snow, honestly, or animals bursting from snow, send those along to [email protected] to these.”

Also, I had a ton of fun producing this episode, like sort of an irrational amount. And I was thinking I might do another episode about snakes.

So if you have snake-related questions, please record a voice memo and send it to us. No question is too silly. Just tell us your name, your age, your question about snakes, and we might use it on the show. We are, in case you missed it, [email protected]. If you would like to support the show, and the journalism that Vox does, we would love it if you would become a member.

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You can say that you can be a member of the studio. But you don't want to be a member of the studio. But you don't want to be a member of the studio. You want to be a member of the studio. And if you then want to be a member of the studio, you want to be a member of the studio. What do you mean? What do you mean? You want to be a member of the studio.

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