Dr. McKenzie Skiles: Science of Snowmelt

As skiers and riders, we hate to think of melting snow. But to Dr. McKenzie Skiles, snow melt is the lifeblood of existence in the mountain west. Last Chair ventured up Little Cottonwood Canyon to join Dr. Skiles in a three-meter deep snow pit to talk about snow melt, the impact of desert dust and what the future holds.

Ski Utah podcaster Tom Kelly and guest Dr. McKenzie Skiles relax in a snow pit for a Last Chair interview. (Photo: Chris Pearson)

An Alaskan native who started skiing when she was two, Skiles had a long fascination with snow. She chose the University of Utah for college because of the snow-covered Wasatch. And when she learned there was a course of study in snow hydrology, she was hooked. She also discovered the Utah backcountry, bought a split board, and ultimately decided this was the place to stay.

Today, as an assistant professor in the U’s Geography Department, her passion is the study of snow – its water content, factors that influence the actual melt, and how that water makes its way through creeks and rivers down to life-giving reservoirs. 

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Her research facility is a short skin up the lower flanks of Cardiff Peak across from Alta to the Atwater Study Plot, named for Monty Atwater, the father of avalanche safety. The study area is cordoned off from passing skiers and snowshoers to preserve the natural snowfall. A meteorological tower contains an array of instruments and measuring devices in the snow weigh the snow pillow to gauge water content.

Dr. McKenzie Skiles stands at the bottom of a 3-meter snow pit at the Atwater Study Plot near Alta. (Photo: Chris Pearson)

Once a week or more, Skiles and student assistants head up the trail to dig a snow pit, taking a variety of measurements of snow cores and evaluating dark layers of dust in the snow white walls. The information is carefully analyzed on-site and back at the University of Utah lab.

The thought of melting snow is something we all hope is many months out. But this episode of Last Chair provides some fascinating insights into how our snowfall turns into water and fuels our lives here in the mountain west. Here’s a sample of the interview. Listen in to Last Chair to learn more. 

McKenzie, what is the Atwater Study Plot?

Atwater is a snow energy balance study plot where we are measuring how the snow accumulates and how it melts out and what is controlling the rates of those processes.

What do you do as a snow hydrologist?

I am really interested in snow after it falls to the ground and I want to be able to assess how much water is held to snow in the mountains. And, very importantly, when that is going to be available as water downstream. So when and how fast will that snow melt? And that's really critical here in Utah and over the whole Western US, because up to 80% of our surface water comes from snow annually. So it's a really critical component of the water cycle in the west.

How did you get into the field?

I was interested in studying climate and the impacts of climate on snow cover in particular. But I didn't really know that snow hydrology and studying snow was a career path you could have until I went to school at the University of Utah. My graduate advisor was a snow hydrologist, and as soon as I figured out that was a job you could have, I didn't really ever look back.

“The reason why we live in the West is because of the mountain snowpack, because of the water that it provides seasonally. If we didn't have the mountain snowpack,
none of us would live here.” - Dr. McKenzie Skiles

How do you evaluate the particulates on the snow?

Actually, you can see a dust layer in this snow pit, it's pretty varied. So we're weighing the total amount of dust that's in the snowpack. We get multiple dust events through the winter and then they get buried by snowfall. And so there are these individual dark layers within the snow pit. So we can track those individual dust layers, but then they don't get carried away in the meltwater they combine at the surface as snow melts. And that is a compounding effect where each layer sort of comes to the surface, the surface just gets darker and darker, accelerating absorption of sunlight and snow melt.

A portrait of Dr. McKenzie Skiles with her skis (Photo: Chris Pearson)

What’s a good melting pattern in the spring?

The ideal scenario is that as days get longer and sunlight gets more intense in the spring and into the summer, we get a gradual melt. We want snow to come out slowly. And what that allows us to do is to capture it downstream. It allows it to infiltrate into the soil and it avoids flooding. And if you have some sort of event like a big dust deposition event or sort of multiple really warm days in a row or something like a rain on snow event, you can have really rapid melt. And when you get really rapid melt, it can lead to flooding downstream – so too much of a good thing at once.

Are others working in unison with you?

There are very talented and dedicated scientists that work here in Utah looking at this issue spanning institutions: Utah State, University of Utah, BYU. It's sort of an all-hands-on-deck situation. The recharge for the Great Salt Lake is coming from the mountains that are right next door. So we have a unique opportunity here to study this, as a system, but then also understand solutions for other areas, because this is not the only place where a saline lake is shrinking and disappearing. So we have the opportunity here to provide solutions not just for us, but for other people in other locations as well.

Dr. McKenzie Skiles has a personal passion for snow, be that split boarding down a backcountry line or spending hours in the field researching snow melt. It’s a fascinating episode of Last Chair.

 

Transcript

 

Tom Kelly: |00:00:02| And this week, Last Chair is off into a field experience again. We've had a lot of those this year. We are sitting in what is a 10 foot or so snow pit. If you think that snow pit that Drew Hardesty dug for us a few episodes back, this one is really, really big. I'm joined by Dr. McKenzie Skiles, a professor at the University of Utah. And McKenzie, thanks so much for joining us. And to you, Otto, thanks for digging this pit this morning.

McKenzie Skiles: |00:00:27| Yeah, thank you for having me on. And yeah, my PhD student, Otto Lang, really helped to get this pit started and dug all the way to the ground.

Tom Kelly: |00:00:36| Otto, by the way, is the individual who had his photo go viral a short time ago ...  which was really cool for people to get a sense of the magnitude of what you're doing out here. We're at the Atwater Study Plot. Just give us a little nickel description to that. We're going to come back to it a little bit more in detail later.

McKenzie Skiles: |00:00:55| Yeah. So Atwater is a snow energy balance study plot where we are measuring how the snow accumulates and how it melts out and what is controlling the rates of those processes.

Tom Kelly: |00:01:08| And where are we right now?

McKenzie Skiles: |00:01:10| We are in Alta, Utah, near the top of Little Cottonwood Canyon. We're right across the street from Goldminer's Daughter in the base of Alta. And if you've ever toured up to Flagstaff or Superior or Toledo, you have walked right past Atwater Study Plot.

Tom Kelly: |00:01:26| I have not been here in the winter before, but I've hiked up to Superior doing wildflower photography in July when there's no snow. And I would always admire this huge tower and, you know, knew it was a snow study plot. Now that tower, it's not so huge right now.

McKenzie Skiles: |00:01:44| No, we have ten feet of snow and it's about, let's see, how tall is the tower? I think it goes up, it reaches 15 feet. So the snow is almost to the base of the instrumentation platform.

Tom Kelly: |00:02:01| It's just fascinating. If you are out skinning and you come by this, first of all, please stay out of the plot. This is snow that's being measured. But take a look. It's really quite an amazing facility. McKenzie, tell us a little bit about what snow hydrology is. And I think as a precursor to this, we've had Jim Steenburgh, Professor Powder, on the podcast a number of times, and he's an atmospheric scientist. So he kind of deals with the snow when it's in the heavens and falling to the earth. But you're a little bit of the different part of that equation in snow hydrology. Tell us what that's about.

McKenzie Skiles: |00:02:34| Sure. I am really interested in snow after it falls to the ground and I want to be able to assess how much water is held to snow in the mountains. And then also, very importantly, when that is going to be available as water downstream. So when and how fast will that snow melt? And that's really critical here in Utah and over the whole Western us, because up to 80% of our surface water comes from snow annually. So it's a really critical component of the water cycle in the west.

Tom Kelly: |00:03:10| And we're going to get into more detail on this later. But I think those of us who are just, you know, skiers and riders, we're following this more just people who live in Utah looking at the Great Salt Lake. I think there's a greater consciousness today about this and learning about snow melt, learning about water content. Are you seeing that as well?

McKenzie Skiles: |00:03:30| Yeah, I think so. And I think what has led to that locally is this crisis with the Great Salt Lake and a desire to understand where the water comes from that recharges the Great Salt Lake every year and that comes from the seasonal snowmelt. And then more broadly, across the west, we've had this long-term drought and the Colorado River has been in national news a lot for reaching record low levels and low levels in reservoirs. And so that has also brought awareness to what recharges the Colorado River every year. And again, that's seasonal snowmelt.

Tom Kelly: |00:04:05| We're going to come back to some of the science in a little bit, but I want to explore a little bit of your background and tell us where you grew up, how you got into winter, and how that led you to become a snow hydrologist.

McKenzie Skiles: |00:04:16| Yeah, so I grew up in Anchorage, Alaska, and what got me into snow when my mom taught us how to ski when we were very young. I've been skiing since I was two. I don't even really remember learning how to ski, just that I've always been able to do it. And growing up I saw changes in the snowpack in Alaska or when it snowed, how long it snowed, how much snow is on the ground. That made me really interested in studying climate and the impacts of climate on snow cover in particular. But I didn't really know that snow hydrology and studying snow was a career path you could have until I went to school at the University of Utah. And when I was there I met my graduate advisor who was a snow hydrologist, and as soon as I figured out that was a job you could have, I didn't really ever look back.

Tom Kelly: |00:05:06| That's really quite an amazing story. Let's go back to Alaska. Where did you ski up there? And were you a resort skier or a backcountry skier? A little bit of both.

McKenzie Skiles: |00:05:13| Growing up, I was primarily a resort skier. I skied at Hilltop ski area, the local ski area, right outside of Anchorage, right in Anchorage, really. And then also Alyeska in Girdwood.

Tom Kelly: |00:05:24| Did you get into the backcountry at all up in Alaska when you were young?

McKenzie Skiles: |00:05:27| I didn't really. I actually started backcountry skiing when I moved here to Utah for my undergraduate degree is really when I ... I'm also a snowboarder and I bought a splitboard and I started getting out and that was really my first entry into the backcountry.

Tom Kelly: |00:05:45| Was that the reason you chose the University of Utah for your undergrad?

McKenzie Skiles: |00:05:49| It was in part the reason. It's funny because I looked at schools in Colorado and I think that's where everyone starts if you want to ski and go to school. But I had a sister who was going to school in Colorado and she told me how long it takes to actually drive to the ski resorts. And in Utah, it just seemed a little bit closer and easier to sneak out and get a few runs in before or after class.

Tom Kelly: |00:06:11| Yeah, it does. You know, it's amazing how many people make that choice and say to mom and dad. I think Utah has a great program here. I just like to come out there. You know, I think I'll get a good education there, which you do, but you get a different education when you get up in the mountains, don't you?

McKenzie Skiles: |00:06:25| Yes. Yeah.

Tom Kelly: |00:06:27| Did you grow up skiing or snowboarding?

McKenzie Skiles: |00:06:29| I grew up skiing first. And then I think this happened to a lot of people. Snowboarding got really cool when I was a teenager and my older brother was a snowboarder, so I wanted to be like him. And so I started snowboarding during my teenage years. And so I now go back and forth.

Tom Kelly: |00:06:49| So let's let's get into a little bit more about where we are, the Atwater Study Plot. First of all, tell us about the pit that we're in and you'll see this on the photographs that are accompanying this on the web page. But this is a really, really deep pit that's got some really intricate areas where you've taken some measurements. But first of all, describe the snow pit we're in and what the functional aspects of this are. And then we'll take a look at the rest of the plot.

McKenzie Skiles: |00:07:15| Great. Yeah. So when we come up here, we're really interested in quantifying the amount of water that is held in the snowpack. And so to do that, we dig a snow pit all the way to the ground, and then we take measurements that allow us to measure the density of the snow. So they're called density cuts and it's a wedge cutter. So it basically pulls a triangle of snow out of the wall and then we put it on a scale and we measure it and we take those sort of triangle cuts all the way down the face of the wall. And when we add up all of those cuts, we're able to tell the density of the snow. And then from the snow pit, we're able to tell the depth. And from that we can calculate snow water equivalent.

Tom Kelly: |00:07:56| Interesting. Now, I know a lot of us who are starting to follow this more, we look at the weather forecasts. There really isn't so much a forecast. But, and after the fact, when you're getting the water content I know there's automated methodology for this as well. Do you have that capability here at the study plot.

McKenzie Skiles: |00:08:12| Yeah. So just this past summer, the SNOTEL program in Utah installed a SNOTEL site, a snow telemetry site here at Atwater, to go along with the instrumentation that we have already previously installed. And at SNOTEL sites, there's automated measurements of snow water equivalent that's measuring the amount of snow that accumulates over a pillow, that is measuring the weight of snow over that pillow. So those measurements are real-time. You could go online and look up Atwater Study Plot and find the snow water equivalent over the snow pillow at any time.

Tom Kelly: |00:08:45| Yeah, it really is quite amazing. So you and your student Otto, have dug this pit? I mean, just how long did it take you to dig this pit?

McKenzie Skiles: |00:08:55| This pit would take a couple of trained observers, so if you know what you're doing, it probably would take about two hours to dig all the way to the ground. And then, because we need to make observations along the snow pit face, we need to make sure it's relatively smooth. So that takes a little bit longer to sort of smooth out the face and then you can start taking observations. And that takes about another hour.

Tom Kelly: |00:09:18| Yeah. By the way, folks, we are down to the ground. And I know if you've been up at Alta and Snowbird, off the roadways, nobody's seen the ground since October. But you're down to earth here, right?

McKenzie Skiles: |00:09:27| Yeah, we are all the way down to the ground and it's 10.5 feet down to the ground from the bottom of the snow surface.

Tom Kelly: |00:09:34| Give us a little history of this study plot. You've been here a few years now, but this study plot actually goes quite a ways back in time.

McKenzie Skiles: |00:09:40| Yeah, this study plot was established by Monty Atwater in the 1940s for the Forest Service when he was up here doing avalanche science. And he really is the sort of father of avalanche science, Little Cottonwood Canyon in the Western US. And he established this plot as a place to come back to over and over again and take observations in the same place. So watch how snow changes through the season in the same place. But he was really focused on snow safety and avalanches, and the site has been maintained as a snow safety study plot. Until today. It was taken over by the UDOT Snow safety program, but now they continue to make snow pit observations here as well.

Tom Kelly: |00:10:23| Interesting. Give us a little sense of there's a tower here with a number of meteorological devices on it, but give me a sense of what you're measuring with all of the devices and the electronics you have up on the tower.

McKenzie Skiles: |00:10:35| Yeah, So for a long time UDOT had some instrumentation here and then they moved it just down the hill to the Alta Guard site. So if you've ever looked at any of the instrumentation up in Little Cottonwood Canyon, you probably recognize that site. And so the platform here was sitting empty for a little while, and when I started my position at the University of Utah, I partnered up with UDOT to put in instrumentation on the platform so we could start observing some of the more common measurements, which include snow depth, temperature and relative humidity, how much moisture is in the air, wind speed and wind direction. Those are kind of the standard meteorological observations. And then we also put in instruments to measure the radiation balance. And what I mean by that is the ratio between the amount of sunlight that is incoming versus how much sunlight is getting reflected off the surface. And from that we can tell how much sunlight is getting absorbed. And then we're also measuring long wave radiation, and that is just radiation and energy coming from the atmosphere itself and then being emitted from the snow. And those two components, the radiation balance, are really important for determining snow processes. And in particular solar radiation or sunlight, just the amount of sun that's coming in. That's the primary control on how fast snow will melt. And so we really want to be able to measure that if we want to be able to forecast rates of snow melt.

Tom Kelly: |00:12:02| Are you able to monitor this real time? So if you're back at the you. Are you able to look at this data as it comes in?

McKenzie Skiles: |00:12:09| Yes, we have a cell modem here, so we can access the data in real time.

Tom Kelly: |00:12:15| Interesting. We're going to take a short break. And when we come back, we're going to talk a little bit more about how snow melts and why that's important to all of us. We're with Dr. Mackenzie Skiles, we are in a ten foot deep snow pit up near Alta. We'll be right back.

Tom Kelly: |00:12:31| And we are back in the snow pit at the Atwater study plant up here near Alta with Dr. Mackenzie Skiles. We've had a fun tour of the place that's really fun. And we're down ten feet deep in the snow right now. The wind is really rustling. There's snow blowing all over the place, as has been the case most all of the year. We want to talk about snow melt now. And I don't think a lot of us as skiers have thought so much about this. We just like it when it's on the ground. We don't like it when it melts. But actually, one of the most important things for our livelihood here in the west is how the snow melts. Talk to us about how critical this is and the work that you're doing to study this.

McKenzie Skiles: |00:13:11| Yeah. So we really depend ... and I don't it's hard to stress this enough ... that the reason why we live in the West is because of the mountain snowpack, because of the water that it provides seasonally. If we didn't have the mountain snowpack, none of us would live here. And so what's really important to understand is, when that water resource becomes available to us to use downstream and then also in systems with reservoirs, we need to know when the water is going to be filling up the reservoir so we know when to let water out of the reservoir so we don't get overspill and lose that water essentially downstream. The water here in the west is very heavily managed. So we want to be able to keep track of basically every drop of water. And then also the water is not just going downstream for us to use, but recharging the landscape, going back into the soils and making sure that our vegetation and mountain environments can stay healthy. And that's really important as well. So water for humans and water for the landscape are sort of the two main drivers to understand when this frozen snow turns into a resource that we can use downstream.

Tom Kelly: |00:14:22| I know that a lot of us last year, we heard the reports of dust particulates coming off the desert, coming off the Great Salt Lake. I know it's not anything new. It's been happening, but last year was a little bit different.

McKenzie Skiles: |00:14:36| Yeah. So what we saw last year and we've been observing dust deposition on snow here in the Wasatch since I was in graduate school in 2009. And last year was unique. Last year we had the most dust events that we've ever observed and we had the most dust mass deposited by double what we've seen in any other year. So there was something unique about last year that led to all of this dust. And, you're right, that basically every year we observe some dust. But when you put dust on the snow surface, it makes it darker, absorbs more sunlight and it melts faster and the degree of melt can be on the order of maybe a day or two. If the dust isn't that heavy or that dark. Up to two weeks last year when we saw a lot of dust deposition. So we're losing the snow two weeks earlier when we get all of that dust.

Tom Kelly: |00:15:36| Do you have a sense of why that happened last year, why we got dust so much earlier, or did some of it have to do with the evaporation in the Salt Lake?

McKenzie Skiles: |00:15:45| We do know that there were a couple of factors that led to more dust. One was the source regions were relatively dry, so we had that really dry January and February last year, and that led to the Great Salt Lake Desert and other areas where dust is emitted from to be really dry. And then we got a series of spring storms that had really high pre-frontal winds. And so those winds just picked up that dust from those dry source regions and brought it to the Wasatch snowpack. And we've modeled now source regions and contributions from those source regions. And we do see that the dry lakebed of the Great Salt Lake is a contributor to dust. It's not the main contributor, but if you look at contribution by area, it is the main contributor. So it's a relatively small area where the dust is coming from, but it's producing a lot of dust from that small area. And so it's a significant factor in darkening our snowpack and accelerating our melt that, you know, if water was in the lake, you don't get dust if it's wet. And so if the Great Salt Lake continues to decline, that will continue to be a dust source. And it's very close. It's basically right next door to the snowpack. So the dust doesn't have to travel far to get here.

Tom Kelly: |00:17:14| I know those of us who were watching last year, I mean, you could see it with the naked eye. I'm sure your observations are more scientific than that. But are you actually taking fresh snowfall and analyzing the dust content in it?

McKenzie Skiles: |00:17:28| Yeah. So what we do and actually you can see a dust layer in this snow pit, it's pretty varied. But what we would do is we would collect a sample of that dust layer and we collect samples at every dust layer that we observe. And we can see within the snow pit, we take it back to my lab at the University of Utah and we filter it out. So we're weighing the total amount of dust that's in the snow pack. And the way it works is that it accumulates. We get multiple dust events through the winter and then they get buried by snowfall. And so there are these individual dark layers within the snow pit. So we can target those samples. And it's almost like a library of aerosol deposition. And that's happened through the winter. So we can track those individual dust layers, but then they don't get carried away in the meltwater they combine at the surface as snow melts. And that is a compounding effect where each layer sort of comes to the surface, the surface just gets darker and darker, accelerating absorption of sunlight and snow melt.

Tom Kelly: |00:18:30| You know, it's really interesting. And look, I had been noticing this on the wall of the snow pit. That is a very defined and almost like about an inch thick layer. So that's a dust layer. And do you have any idea about what time this winter that came from?

McKenzie Skiles: |00:18:45| That one was probably November, late November, we had a lot of snow this early, early this winter. So we think that one was early November and that is probably just from the source region still being dry from the summer and not wetting up yet. So if you go out to the Great Salt Lake Desert right now, you'll notice that the surface soils are saturated or pretty wet and we don't get dust under those conditions. Those regions have to be dry.

Tom Kelly: |00:19:13| This is a little bit of a short term thing, but people are getting a little bit excited because what snow melt there has been this winter is actually putting some water back in the Salt Lake. Good things, certainly, but not a fix.

McKenzie Skiles: |00:19:25| It's not a fix. It's, you know, we'll take everything we can get. A good snow year is good for everybody, but we have a lot of catching up to do. We've had many years at or below average and one good year won't recover us to the place that we need to be. So all of this snow is great and it's good news, but we would need multiple years like this to bring the Great Salt Lake back up to its average.

Tom Kelly: |00:19:58| So let's talk about spring and something that skiers and snowboarders really dread, and that is when the snow does melt and we have to go back to summer activities like mountain biking. But there is a lot of snow this year in some places. And just a remarkable winter for skiing and riding. What are you going to be watching and what do you foresee with this snow melt coming up over the next four or five months?

McKenzie Skiles: |00:20:22| I think what we would like to see the ideal scenario is that as days get longer and sunlight gets more intense in the spring and into the summer, that we get a gradual melt. We want snow to come out slowly. And what that allows us to do is to capture it downstream. It allows it to infiltrate into the soils and it avoids flooding. And if you have some sort of event like a big dust deposition event or sort of multiple really warm days in a row or something like a rain on snow event, you can have really rapid melt. And when you get really rapid melt, it can lead to flooding downstream. So too much of a good thing at once.

Tom Kelly: |00:21:04| And there's really no way to forecast that, is there? It's just going to happen with the weather.

McKenzie Skiles: |00:21:09| The best we can do is watch the weather and potentially, you know, say a few days out if we know a really warm storm is coming, that could do rain on snow, then then you could say, hey, that's the potential is there for rain on snow flood event. But it's challenging. It's challenging to forecast how.

Tom Kelly: |00:21:30| Let's look a little bit into the future and how does the work that you do? Mckenzie Now, how does that help legislators, businesses, other research scientists? How does it help them to better plan for the future?

McKenzie Skiles: |00:21:45| Well, I think there's two aspects to my work. One is this like coming out in the field and digging snow pits and looking at how much water we have now. But then the other part is looking at long term records, including from satellites and other observation stations. And that tells us the long term trends. And the long term trends show us that snow is declining, that we're getting more precipitation as rain rather than snow. And that is a future. We know what to expect. We're just going to have less snow in the future, although it will be very variable from year to year. And so we just need to prepare for that now. And we're seeing some of the impacts of that like stress on the Colorado River, because we've kind of assumed the future is going to be like the past and we can't really assume that any longer. And so planning for the future where there's less consistent and potentially less overall water. And then locally here, you know, I think, you know, everyone is thinking and talking about the Great Salt Lake and there are lots of reasons to save it. And, you know, this accelerated snow melt issue is just one of many reasons to keep the focus on the Great Salt Lake. And I worry we have a big winter and a lot of snow and the lake levels come up a little bit and the attention is lost from the issue. But we need to keep the pressure on to keep the policymakers focused on the Great Salt Lake and maintaining that ecosystem.

Tom Kelly: |00:23:19| We had a great Last Chair podcast with Representative Tim Hawkes this fall. We did that out at Antelope Island and just walking with him along the shores, it was really sad. And, you know, I think a lot of us with all this snow, you know, we are pretty optimistic for the future. But as you said, it's really something long term. Your work is very important to the future. And I'm sure you do work regularly with those other scientists who are looking at the Salt Lake and looking at solutions. Is there kind of like a team of people who are collaborating to try to give us the best direction for the future?

McKenzie Skiles: |00:23:57| Yeah, there is. There are very, very talented and dedicated scientists that work here in Utah that are looking at this issue. And, you know, they're spanning institutions. Utah State, University of Utah, BYU. It's sort of an all-hands-on-deck situation. And, you know, it's a complex but small system. You know, the recharge for the Great Salt Lake is coming from the mountains that are right next door. So we have a unique opportunity here to study this, you know, as a system, but then also understand solutions for other areas, because this is not the only place where a saline lake is shrinking and disappearing. So we have the opportunity here to provide solutions not just for us, but for other people in other locations as well.

Tom Kelly: |00:24:49| Do you also, as a part of your work, do you look at other snowpacks around the world and draw some lessons from those scenarios?

McKenzie Skiles: |00:24:57| Yeah, so I do primarily focus on the Western US, but I have had the great fortune of traveling all over the world. I've been to the Alps, I've been to the Himalayas, I've been to Greenland. And in those places I'm trying to understand what controls snow melt rates and evolution of snow cover in those different environments and how different places on earth have different controls on what's changing those environments.

Tom Kelly: |00:25:25| This may be a little bit out of your field, but glacial melt is well, that's not a real Utah thing, it's a very big thing around the globe right now.

McKenzie Skiles: |00:25:32| Yeah, that's true. And I'll draw an analogy to what we were talking about in the snow pit. I said that those dust layers don't get pulled away with the meltwater, but the same thing happens on glaciers. So glacier ice, if the glacier is declining, glacier ice will just keep getting darker and darker and darker because all of the previously deposited dust and dark aerosols just combine at the surface. And so it's the same thing on glaciers where if it's a declining glacier and not growing, it just keeps getting darker and melting faster over time.

Tom Kelly: |00:26:05| Yeah. Mackenzie Skiles, thank you so much for joining us here on Last Chair. We want to finish up with our Fresh Tracks section with a few final questions. And the first one, I mean, you deal with snow all the time. We're sitting here on a 10 foot deep snow pit right now. What's the biggest snowfall that you've ever been involved with in your work?

McKenzie Skiles: |00:26:22| Yeah. So I think this is a really deep snow pit, but it's not the deepest snow I've ever dug. During graduate school, I did my PhD at UCLA and spent a lot of time in the Sierra Nevada. And when it goes big in the Sierra Nevada, it goes very big. So this is a three meter snow pit. And there I've dug a five meter snow pit and you basically need a ladder to get down into the snow. And then another deep one that I dug was at Rabbit Ears Pass in Colorado and that one was about four meters. So maybe we'll reach that this year in Utah. Who knows. 

Tom Kelly: |00:27:01| I kind of think we will. Yeah, your favorite resort run in Utah.

McKenzie Skiles: |00:27:06| So it's a bit of a nostalgia thing. When I was an undergraduate at the University of Utah, I spent a lot of time at Snowbird. And I still think, you know, it's you know, a lot of people have discovered the magic of Snowbird, but if you can time it right and get a rope drop into Mineral Basin on a powder day, it's their reputation is well deserved.

Tom Kelly: |00:27:31| And this is why you came to the University of Utah. Right?

McKenzie Skiles: |00:27:34| Exactly.

Tom Kelly: |00:27:35| How about a favorite backcountry line?

McKenzie Skiles: |00:27:37| Well, we're pretty close to one of my favorites, and that's Flagstaff or Emma's. But, yeah, a lot of people have discovered the great backcountry skiing in the Wasatch. So recently I've been traveling farther and farther afield and trying to get into areas where maybe there are fewer backcountry skiers but still great skiing. And those ones I'll keep a little secret. Those are secret stashes.

Tom Kelly: |00:28:05| Dare I ask, what's your favorite season?

McKenzie Skiles: |00:28:09| Well, you know, I do love all of them for different reasons. But I'm a fan of snow and I love skiing and snowboarding and I love winter.

Tom Kelly: |00:28:18| I know you've moved down here from Alaska, but if you picked up a favorite High West whiskey yet.

McKenzie Skiles: |00:28:23| You know, they're all really good and I've enjoyed the tastings that I've done at High West but I'll say Campfire.

Tom Kelly: |00:28:30| Love, Love, Campfire. Dr. Mackenzie Skiles, thank you so much for bringing us into the snow pit on this blustery day here at the Atwater study plot. Really appreciate your contribution and telling us more about how the snow melts.

McKenzie Skiles: |00:28:42| Yeah. Thank you so much for having me.