- Welcome, everyone, to Wednesday Nite @ the Lab. I'm Tom Zinnen, I work here at the UW-Madison Biotechnology Center. I also work for UW-Extension Cooperative Extension, and on behalf of those folks and our other co-organizers, Wisconsin Public Television, the Wisconsin Alumni Association, and the UW-Madison Science Alliance, thanks again for coming to Wednesday Nite @ the Lab. We do this every Wednesday night, 50 times a year. Tonight it's my pleasure to introduce to you Ross Edwards, who's coming to us both from the Curtin University in Perth, Western Australia, and he's here as a visiting faculty member in our College of Engineering. He was born in Portland, Victoria, in Australia. And he went to PHS, Portland High School.   (laughter)   And then he went to MIT, the Royal MIT, the Royal Melbourne Institute of Technology.   (laughter)   He made that joke, not me.   (laughter)    - Thank you.   (laughter)   Okay. And then he got his PhD at the University of Tasmania. Does everybody know where Tasmania is.  - Yeah.  - Wow, I didn't. It's in Hobart. And I'm going to look at the globe again to see if there's any more southern PhD-granting institution in the world. (laughter) And, appropriately, he got his PhD in Antarctic studies.  I hope he'll talk to us a little bit about the Southern Ocean because, of course, the Australians know there's an ocean called the Southern Ocean. Tonight he gets to talk to us about this great expeditionary science that's titled "Dark Snow," investigating smoke on the Greenland Ice Sheet from a zero emission, wind-propelled sled. It's a great pleasure to welcome Ross Edwards to Wednesday Nite @ the Lab. Please join me in welcoming Ross.   (applause)    - Can you hear me? I think that's the first question. Well, first of all, thank you for taking the time to come tonight. I know that seven o'clock is getting late already. And thank you for inviting me. This is a great honor. Tonight I'm going to talk about this trip I took recently across, sorry not across Antarctica, across Greenland. This is probably one of the craziest things I've done in my research career. And I'll explain a little bit about how this came about, how I got involved in this. But, to begin with, I'd just like to thank some of the people or organizations that have been involved, that made this possible. We had some funding from the Dark Snow Project, which is a crowd source, crowdfunded project based in Copenhagen. This is the Inuit WindSled. This is organization that actually came up with this craft that you'll see later on. University of Copenhagen and, of course, University of Wisconsin. My research fellowship is through Curtin University. But the group who really made this trip possible would by my family, the Liddels and the Konkels, some of whom are here, who kept it together while I was away. So this trip really, this is what I've been studying for the past few years. When people ask me what I do, am I a chemist, am I a physicist, am I an Earth scientist, I'm really all of these things. And this is what I've been studying for the last 20 years, 20 years or more. This is actually-- This is the Earth as you'll see it if you were in the Lagrangian point, L1, which is a gravitational sweet spot between the Earth and the sun. This is a real. This is the actual picture. This is not a computer simulation. This is a satellite. This is the NOAA Deep Space Climate Observatory that's out about a million miles from the Earth. And you can log onto this. There's the, if you look up EPIC camera NOAA, I do this daily. When I should be raking the leaves or doing something else, I'm probably watching the Earth from a million miles away. If you look at these images, you really start to get a sense of what really is going on with the Earth's climate and how the climate works. What you're seeing here right now is really a snapshot from May 23rd. This is the day that I landed on the ice, and you can see Greenland up here on the top. Here we go. Up here on the top. Sea ice and snow, clouds, etc., is what you can see is-- Also you can see the Earth's climate system at work.  In reality, what you're seeing here, though, is weather. So people often confuse weather and climate. You'll hear people picking up a snowball early in the year and saying there's no climate warming or no climate change. But what they're really experiencing is weather at one point in time in the Earth's system. And as an Earth scientist, we think of climate as weather that's averaged over some long-time period. We think of the Earth as well. It's not usually one small area that we're really thinking about. We're thinking about the whole Earth. The nice thing about the poles is that we have an ice cap in Greenland and a few other smaller ice caps around and ice caps in Antarctica. And those ice caps are capturing climate and weather and atmospheric chemistry in the form of snowfall. And that snowfall is building up on the ice sheet, and we have records that go back in Greenland that will go back over 100,000 years in some places of the daily snowfall, the chemistry, the atmosphere that's falling on the ice sheet. And so, from my research, I'm interested in the Earth's system. I'm interested in how the biosphere, the living part to the Earth, interacts with the climate system and how the climate system interacts on those aspects of the Earth's system. And so... my work really started off in the Southern Ocean when I was a PhD in Tasmania. And I was looking at plankton in the ocean and the interrelationship of that plankton with desert dust blowing into the ocean, providing nutrients for the plankton. And as part of that research I realized that one of the aspects I was missing was fire. I was researching dust and I couldn't work out how some of the nutrients in the dust was being liberated for plankton. And it turned out there's an interaction between dust and fire. Fire producing smoke, smoke releasing organic acids, organic acids which were aiding the dust in the atmosphere as it was traveling through the air. And I realized that what I really wanted was a record of smoke, of fire, from these ice sheets. And at the time, we didn't have the technology to really do this properly. And I spent a whole decade, I guess, trying to develop a method to do this. And, finally, I had a breakthrough and I developed a method that was about a million times more sensitive than anything that existed at the time. And that allowed us, for the first time, to get these very high temporal resolution records of smoke in these ice sheets, which I could relate back to this whole dust question. Anyway, to move forward-- This is the team that went on this crazy expedition. And this expedition was really to look for smoke, for me was to look for smoke in the ice, in the snowpack.  I had been up in the snowpack before, and we'd traveled in a very conventional way, in planes and aircraft and we had big generators and we were producing a lot of smoke.   (laughter)   Right? You can see where this is going.   (laughter)   And so this opportunity came up to try and travel across the ice sheet without making smoke, without much combustion at all, without using diesel generators and things like that. I thought, wow, this would be a great way to be able to collect snow really cleanly without getting smoke in it. Anyway, so... This is the Inuit WindSled here in the background. So this is this vehicle that we traveled in, and I'll talk a bit about that in a moment. But this is the WindSled team. Before I got up to Greenland I had never met these guys.   (laughter)   The story is getting a little bit more crazy. So this is actually the leader of the-- the team leader. This is Ramón Larramendi, the expedition leader. He's a Spanish polar adventurer/explorer. This guy walked to the North Pole many years ago for SAS. In his 20s, he journeyed from Greenland to Alaska by dogsled and kayak and back, I believe, during the winter at 14,000 kilometers. It took him three years. He said it took him a lifetime. It was a lifetime. He's also taken-- So he created this vehicle based on his experience. He's also journeyed to the South Pole in this thing, unsupported. Yeah, it's wild. This is a Nacho Garcia. He's an extreme filmmaker. He's making a documentary about this vehicle. He was along filming. Hilo Moreno, he's a polar and alpine guide. He works in Antarctica in the mountains, Spanish. And Jens Jacob Simonsen, who we call JJ. He's a Greenlander. He's a captain and marine engineer. It turned out that actually this vehicle was the closest thing to sailing that you'll ever find on an ice sheet. It was apt.  And so we had a couple of goals for this trip. The first, the trip happened in May 23rd to June 23rd, and we traversed about 750 miles across the ice sheet. Along the way we stopped at 13 research sites, where I collected snow samples, dug pits for snow, and then also took some tube samples where it was tubes into the ice for this black carbon. And there was some atmospheric sampling going on as well as meteorology and ice radar.  So this is back to the fire thing. Okay, so my obsession with fire and smoke is really about these little black particles of soot that are in the smoke. They're nanoparticles. They're on you right now. They're in your hair. They cover every surface of the Earth. There's zillions of them around, and you don't see them except when there's a fire or some kind of smoke. So it comes from wildfires. It comes from any kind of biomass burning.  It comes out of your car. Anything that's burning fossil fuels. And before I went on this trip, I gave a talk at the Water Science Laboratory about this trip, to some students, and I said the one thing that we really think is going to happen in the future is that there's going to be more and more burning in the north, in the Canada, in Alaska, in the Siberian Forest. And just as you recall us coming back, these fires started in British Columbia. Some of the biggest fires every recorded in British Columbia. And the smoke did arrive in Greenland, actually after I left. But this is this big river of smoke that is filling up the northern North America. It came down over Madison actually, which was unprecedented in some parts of Canada. It's not unprecedented for Canada to burn, but more and more of these events seem to be occurring. And, actually, after I left as well, Greenland caught on fire. So there was actually a fire in Greenland in the tundra. And there have been fires before but they're rare. But this fire, it was warm enough in Greenland for these fires to burn, actually, for a long time. There was enough carbon in the soil for it to just keep burning. So these fires, the smoke gets transported to Greenland and then gets bound up in the snow. Okay? So that was actually what we were looking for on this trip.  These are some of the sites I'm involved. I've been working on in the past, these so-called ice core sites. So these are sites on the, this is the Greenland Ice Sheet. These are sites where I've been involved in ice core records. So drilling down into the ice sheet. The most recent one is this one here, Renland. The Renland Ice Cap on the side of Greenland called RECAP. These red ones, I was on this, I was part of this drilling activity in 2000 as part of a NASA project where we were drilling these ice cores mainly to look at radar signatures from the ice and to go down into the ice and try and get dates for layers that NASA and other folks could find in the ice sheet. They fly over with aircraft or along the ground with a radar, and they have these lines in the ice that are somehow related to the chemistry that we find in the ice cores. And by dating the ice cores, we're allowed to-- We created a network of ice cores that you could translate the radar signature into a chronological sequence. And so I was involved in all these records, and more recently this one from Devon Island here as well. But one of the things I did, I realized after I'd developed this black carbon method was that there is a lot of spatial variability from site to site. There tends to be a very uniform trend in some of these records, but there's events will happen where fire or smoke from somewhere will impact one site and not another. And so we're trying to get a snapshot of the snow surface during this trip. If you look at the relief of Greenland, you can see here too that this is an exaggerated topography of Greenland, if you like. You can see that these ice core sites are on different sides of the ice sheet. And the topography affects the transport of chemistry to these sites. The other thing I'll point out too is this is the ice core site I've just become involved in, EastGRIP. And this site is on a river of ice. You can see on this relief it looks like there's actually a groove in the ice. Actually, at one point you can see that I'm going down the ice. And this is a really important site there's a big international project working on right now, and the reason is that the ice speeds up as it comes down towards the coast. And there's a high velocity sort of ice stream, which is important for the ice, the balance, the ejection of ice from the ice sheet. 

 This is kind of, this is some recent work as well. So this is the bed topography of Greenland. So if you were to take away the ice sheet, one day in the future, maybe it's 10,000 years, but in the future, if the ice sheet melts completely, this is what Greenland would like. There will be sea water in the middle of it. This is really cool. So there are canyons also that have been recently discovered up this north end. So when this finally disappears it'll be a really spectacular country where the ice sheet used to be.  - Yeah, but so, some of it's below sea level. That's, yeah, 10,000 years maybe. But we know from the last warm period that there was some ice still. The last warm interglacial warm period around 120,000 years ago there was ice still on, some ice still on Greenland. It was slightly warmer for a brief period than today, but we're projected to go way beyond that this time. And if you then put the ice back on, if you take away the bed, you have the actual ice thickness. And so the ice in Greenland is over 3,000 meters. I'm trying to think in illogical units into feet. It's over 10,000 feet at the summit. Okay? So this is the ice sheet now if you were to take a cross-section. This is what I was talking about where if you drill an ice core, this is a place called Camp Century, if you drill an ice core down here and another ice core here and another ice core here and then you fly over this ice sheet with a radar, then you can see these radar return lines. And some of these lines are from things like volcanic eruptions that have made the ice more acidic and it's affecting the radar return. But there's these constant lines, these lines of common age, if you will. So it's like a tree ring. Once you have the dating from the ice cores and the radar return, the ice sheet starts to become like a big tree. Like a big onion or a tree ring. So you can go down into the ice sheet now from a three-dimensional way and know something about the age. And, also, if you know something about the age and the mass and then the velocity of the ice as it's coming off, then you can tell a lot about its dynamics.  And this is what an ice core looks like. I'm not going to go into the whole drilling and everything else. But Madison has been a part of the ice core drilling for many, many years. In fact, right at the very beginning of it. This is a colleague holding up a piece of ice. This is a shallow from a shallow core. But this is basically what we're working on, but many, many, many kilometers of this ice. Okay, so it can take, these projects can take 10 years to plan and then 10 years to drill, in some cases. And then... Yeah, so many years to analyze them. So they're very long-term projects.  The other thing I'd say about Greenland too, there's a lot of debate about, you know, is Greenland melting down or not melting down? And we have-- There's a lot of evidence for the current rate of melt. This is the GRACE Satellite. I don't know if you know about the satellite, but there's these fantastic satellites that NASA has. They're orbiting the Earth, and they're connected by a laser beam. And these satellites are basically slowing down and speeding up due to gravity. And so they're measuring the Earth's gravitational field over a point, and so, from that, we have this record now of the gravitational field of the Greenland Ice Sheet. And we can see the ice coming off Greenland on a fairly, you know, on a seasonal basis. And so this is from, this is ending now in-- Let's see, it's from, I think it's from 2012. But this is 2012 here. And so you can see the ice coming, the seasonal change in the ice, off, on, off, on. And so it's coming back because of snowfall. So there's a melt season. There's icebergs carving up the coast and there's a bit of a melt and then there's snow coming back onto the ice sheet. So the mass, there's a return of mass. But in 2012, there was this really dramatic drop. I think over this period here the ice mass loss tripled. 2012 was this really anomalously warm year. And a part of what happened, though, was that the snow didn't really come back on. The ice mass from the snow didn't really, you know, bounce back. And that was partly because there was a large-- It was an anomalously warm year, and the snow on the surface, the melt rate of the snow on the surface increased. The melt increased and there were rivers of water coming off the ice sheet and so a lot of that snow didn't come back on.  So a part of the studies that came after that were to look at, well, okay, why is the snow melting? What are the parameters that affect the snow melt on the surface? And temperature is the obvious one, but, also, the reflectivity of the ice. The albedo of the ice. How reflective is it? And the things I've been studying, black carbon, actually affect that. They affect the surface albedo, as does dust and life, actually. There's an algae bloom starting on the edge of the ice now. And it can be this vivid purple color. They're absorbing sunlight, so they're speeding up the actual melt. But the point here, I guess, is that there is no debate about Greenland losing mass. It's losing its gravitational field. It's losing mass, okay? So this is kind of where we're at now. I think the current annual rate of mass loss is something like, I think it's 456 gigatons. And it seems to be accelerating. Although, it may have slowed down in recent times. And so that's about, on average, it's about .03 of this whole-time series. About .03 inches sea level rise, but that's over this whole record. At the moment, I think Greenland's contributing about at most probably 25% of sea level rise. At the moment. Yeah. That's one of the upper estimates. There's quite a sea level rise, I think, is, at the moment, somewhere nearly up to three millimeters a year going up. Once upon a time people looked at that thinking, well, it is not in my lifetime, but now we're starting to feel sea level in our lifetime. This is what I was talking about, about the melt. This is at the edge. So there's all these complicated things happening on the edge of the ice sheet with meltwater coming off, with darkening of the ice from soot and dust, and then, also, life. And so this is typical of any ice body really, but it's creeping up. And as it goes up, the melt rate is increasing.  So the other thing I was going to say, though, is that this whole thing that I got involved in really, part of it was because when I did this NASA project as well, we were flying around in aircraft and we were diesel and there's smoke everywhere, and in some ways it didn't really feel right. You know, we're trying to do this environmental, we're looking at this environmental record and thinking, wow, man, we need to change emissions and all these things and yet here we were emitting all this fossil fuel. And so there's been a lot of debate about this in academic circles about how we can improve our carbon footprint, etc. And people have talked about going to less conferences and things like that. But what we were really thinking of trying to take it to the next level and see if we can actually do this without, we still need to go out in the field, we still need to travel around the world to do our work, but could we do it without fossil fuel. And so this is the Inuit, this is a sled. This is the Inuit WindSled that we took. So it's insane, right?   (laughter)   When I saw this, when I first saw this, this actually looks more impressive. It looks kind of like a spaceship. I thought, wow, okay. And one of my colleagues actually approached me at a bar in Copenhagen with this idea. I thought, I think it could work.  And so this is the concept. You have a multiple sled system with a tent at the back for sleeping, some food and other gear in this next compartment, solar panels on these, and then this was to be the science module. And so we'd store ice core samples or snow samples and things like that in this section. And then this is the piloting tent. And so the idea was that we'd have this massive kite, 350 meters away from the sled, and that would pull us across the ice sheet. We would rotate in shifts. So some people would be, there's no sleeping on this. It's a wind sled. It's resting. Some people would be resting.   (laughter)   Okay? Resting in the back. And then some people would be piloting. Someone else might be making water. And then we just rotate, and basically you might climb across these and someone would climb back.  So, in theory, it seemed like it was possible. The concerns that I had-- I had some concerns. (laughter) The concerns that I had originally actually wasn't the things I should have been concerned about. It was about power. I was thinking what kind of science could we do on this? And, really, could we generate enough electricity from solar panels? And what were the accelerations that we'd experience in the sled? How rough would it be? I actually did a lot of training, a lot of work to put muscle on my back before this trip because I realized that I'd be punched, punched in the back about a million times, actually. The undulations of the ice. You figure out how many times you're going to get smacked in the back. So, anyway, this is the concept. And I hadn't seen-- I hadn't really seen the actual craft itself. And this was the actual plan. This was the plan for our traverse. We'd start off down here near Kangerlussuaq, and... we would make our way up the ice. And then we'd sample a few sites along this side of the ice divide. And then a whole bunch of sites close together, down towards this new site, this EastGRIP. And so this was at least the concept. And so the other thing was that some of my colleagues that I thought were actually going on the trip, sort of took a step back.   (laughter)   In the end I think I was the last scientist standing.   (laughter)   Anyway, so this is-- Oops. If I can... Sorry, this should kick in.  Okay. If I'm lucky, it'll just start up. There we go. So this is going to take us down, this Google Earth is going to take us down to Kangerlussuaq, where we started. This is the main airport, the main hub of Greenland. This is also the Kangerlussuaq Sound or the Fjord. It's one of the longest fjords. And this is down now to the-- This is Sondrestrom. This is a US Military Air Force base, I guess you'd call it. And now this is the ice. You can see this zone here. This is the danger zone. So there's a death zone between Kangerlussuaq, where we started out, and where we needed to get to. And this is our traverse route. And so the first of several--  Let me get past this. Several-- Several--  What am I trying to say? There are several stages to this trip. And this is the first part. This is the part that worried me probably the most. This is the crevasse zone near, just on the ice edge. And so in order to begin this journey, we had to get over this death zone. So just cracks, crevasses everywhere, and then melt pools. And one of the concerns was that if we didn't get into this trip early enough, there would be melt. And then, actually, then we'd have a real problem. A previous attempt to do one of these trips by the WindSled crew, they were very lucky because they didn't know it but they started off going over a freshly frozen pond. So imagine on the ice there's a lake on the ice and it's just below you and you can't see. And then the lake's draining somewhere and so there's a little bit of snow over the top. So we started off fairly early in the season and then we actually went way further. We managed to get a helicopter that would fly us to the beginning and to fly us far enough inland that we would miss the cracks and the death pools. We were also concerned about polar bear. You know, it's one of these things, we were worried about polar bear. The chances were low, but they had to shoot a polar bear at this base where we ended up the year before. And it wasn't-- The story that people will say is if a bear's gone that far up on the ice, it must be crazy and weak and something like that. And this bear wasn't any of those things. And so we were concerned, and we did have a gun with us. Although, we tested the gun, and I can tell you it wasn't going to stop a polar bear.   (laughter)   It would make a tough polar bear very upset.   (laughter)   So this is Kangerlussuaq. So the first stage, actually, was to set out the sled and to repair the sled that had been stored away. And so my job for the first week was actually restringing the sled and drilling holes in it and doing some retrofitting. One of the things about Kangerlussuaq is that in Kangerlussuaq you can't get anything. You can't get duct tape. You can't get nuts. You can't get bolts. These are my colleagues. This is us pulling the gear out of the container. And we, I don't know if you can hear this. We rebuilt the sled. (inaudible) Add on the deck. When I saw it here, this is when I did have a feeling of dread.   (laughter)   I thought, what is this? It doesn't look like much. It looks really primitive and it looks really loosely roped together.  And, in reality, I didn't understand what-- I didn't understand some of the principles of these sleds. So the idea is that the Inuit knowledge that was put into this sled is that it has to be a living, it's a living entity. It has to move. It has to move in all sorts of directions. If it doesn't, it will just snap apart. And it looks primitive, but actually there's some high-tech rope involved. Some very high-strung rope. The actual wooden beams look like just lumps of wood, but they've got, they're laminated birch with fiberglass built into it, high density polyethylene. It still looks a little iffy, right?   (laughter)   That it's going to go across the ice sheet. The other thing, though, is that, so there's the flexibility of it, but the whole concept is that if something breaks, then we're going to be able to repair it. If it was a Ski-Doo or some big PistenBully or something like this, if an engine breaks, you're done. But, in this case, we could fix everything. The whole thing could be ripped apart, and we could put it back together. So this, we spent like five days, at least, doing all this. It took a long time to really string it back together. We're replacing bits of rope, etc. Actually, my hands were cut to pieces. This is another stupid thing I did. I didn't wear gloves, and so when I got on the ice, I could barely move my fingers. There's some tiny little slices. 

 So, yeah, I'd call this techno-primitive. That's what I think I would call it. It's subtly, this technology image   (inaudible)  .  So, food. Oops. I will attempt to show you what it was like once it's actually running. This is actually what it looked like when it was assembled on the ice. And so this is a 3D image that I took that's actually now splayed out. And what you'll be able to see is up here is the kite. There's someone pulling, there's someone actually working the kite from the side. And then I'm holding the actual camera. So...  - (crunching of ice)  - This is what it was actually like when it was going across the ice.  Again, this is a three-dimensional-- This is a complete image that's turned around. And this sled now is over two-and-a-half-ton.  Okay? So...  Yeah, it was almost like a-- I call this a magical. This is a very surreal experience in the sense that you're-- All we can hear is the crunching of the ice and someone playing some music. But you're pulling this kite in a figure eight kind of configuration. So you would pull it, if you want to turn and head in, say, this direction and the kite would be flying, you might fly over this way, turn around in a figure eight, and then catch the wind again. And so this is constant pulling of the kite up and around. This kite is so far away, the kite is so far away that you're, you can sort of see it off in the distance. And the kite itself is about, I think the biggest kite-- We had about 10 kites, but the biggest one was about 80 meters in surface area. The first day when we landed on the ice, and hopefully I can get this thing to go back and wake up again.  But the first day that we got this, we landed on the ice and we spent two days reassembling this sled. We packed into a helicopter so we were able to build it up and then break it back down again. And the first day we set it all up, and there's an emergency release on the kite. So a couple things can happen. When you launch this kite, if the kite, if the whole thing takes off too fast, the wind picks up, you have this big kite, there's a good chance you're never going to get down.   (laughter)   Okay? And so the thing's going faster and faster and faster, and eventually this whole sled will be ripped apart. And, you know, you can imagine a two-and-a-half-ton thing just going. And so there's a pin, the emergency release pin. And so the idea is that there's one person next to this pin and another person's trying to sail. And the Spanish word is soltar, soltar, release, release. And the first time we were going to launch this kite, I was next to this pin. And Ramón was yelling out, " Soltar, Soltar!" But to someone else, about something else. And of course I pulled the pin. (laughter) And launched the kite. (laughter) The result of that was we were there for another two days.  I'm not feeling confident here. This is going to get back to itself.  A complete collapse. So once we did get the kite going again, it was really the most magical feeling that you could imagine. Just cruising across the ice with seemingly nothing pulling you because it's way off into the distance. The thing I didn't count on was that you'd get seasick.   (laughter)   Yeah, yeah. So if you weren't piloting the sled, then you were resting/sleeping. And inside the tent-- So it got down to minus 30 or close to minus 30 when the sun dipped down. The sun never set, but it did dip down. And then, during the peak, it could get up to-- Let's say once or twice it got to minus two Celsius. So almost got to melting, actually. But, typically, it was minus 15 Celsius. And so you were in your sleeping bag, you're in the tent, but the undulation. So the sled was actually moving in this kind of way, and then also this way all at once.   (laughter)   And so the bump profile on the ice is, you know, this. And so, yeah, so it started off like I couldn't believe it. This is magical, this is great. And then--   (laughter)   Yeah, okay? And then I was sick, feeling sick. And also being punched in the back. And so, yeah, I lost a lot of weight. So during this, we had 40 days of rations with the idea that we would get across the ice sheet in 30 days or to EastGRIP, 750 kilometers.  So we had plenty of food, but, for me at least, I wasn't used to Spanish food. And so some of the rations were lomo. Does anyone know lomo? It's this really thick ham that's paprika. And so I had trouble digesting it. And I was seasick a good chunk of the time. Yeah, and so I lost about, let's see, I lost about, I'm trying to think, 20 pounds or more. I completely shriveled up. (laughter) And then, also, for a large amount of the trip we were above 9,000 feet. So for a good chunk of it we were at 9,000 and 10,000 feet, and so we had elevation. And in Greenland, 10,000 feels like 15,000 just because of the low air pressure. And so all of us were suffering from that as well. 

 And so the big problem was just your body shutting down as well. When we got to stop, there's a couple questions that people usually will ask, and one is, how do you go to the bathroom if the sled is always moving? (laughing) So that was one of the difficulties, actually. One of the difficulties of this trip was basically when we, you know, the time that you had to stop to go to the bathroom, which was basically just running off and digging a hole, and then being able to do that in sequence with the moving.  When we were at a site, the way we would stop the sled, if we could, was to-- So if you think about the way that the kite would work, the angle of the kite versus the motion or the direction that we're going at, if you bring this sled up really, really high, then eventually the force forward is diminished and the sled would just stop. And so the way we did some of the sampling was that someone would hold the sled, hold the kite so that it was just flying just above. And then I'd basically have to jump out and dig a hole as fast as humanly possible because a person would still be driving the kite.  - Was this taking a sample or leaving a sample?   (laughter)    - Taking it. Yeah, if you dig that pit, you get to use it.   (laughter)   Yeah, so I think, yeah, so basically what I was doing is I would get out, I would drag my gear out, put on a clean suit, like a white suit so I didn't contaminate the samples, and then the goal for my black carbon samples was to just take the top 20 centimeters. The reason for that was that that's the depth, I guess, that the light is penetrating into the snow pack and really interacting with the soot, the little black smoke that would be in the surface layers. And so I was coming or approaching the site from downwind, putting on a suit, and then I had a few tools that I could measure down, so five centimeters into the surface of the snow. And then I had a clean tube which then I was extracting that five centimeters of snow. So I was taking, doing duplicates of each step, and then down to 20 centimeters at each site. So I'd carefully do that. And then I would dig like crazy. So I was digging two-meter pits, two-and-a-half-meter pits in some sites. And then taking a long tube made of carbon fiber and just pushing that gently, vertically down on the side of the pit, and then trying to extract it out through the pit wall. And those tubes are basically a depth profile of the snow, which then we could take back to the lab in Copenhagen to analyze in very high, one-centimeter depth profile along the tube. So I was taking two meters, two of those tubes, one on top of the other, and then having to extract them out. So I was digging, some sites I think I dug a three-meter pit. 25 minutes, that's my best one.  - What did you use for digging?  - A shovel. (laughter) I was digging like an impact crater. It was crazy. Just because some poor person was having to hold this thing. And it did get really cold, actually, when you were piloting the sled.  Once we got to the-- I think mid-way we got to the ice divide. So a lot of the time you were sort of going up, up, up, up. And then you could actually see it. There's a slight undulation in the snow going up. And then we reach the ice divide, and then you could actually feel it going down. It was kind of crazy. Part of it was an optical illusion, I think. But we're going down and the sort of terminology was surfing the ice river down towards this, to EastGRIP. The other thing I was going to say is we had some emergency procedures because the nice thing about the sled is that you have a tent already made. You don't have a pull out a tent in an emergency. And so the tent's there, but there are these storms that come up over the ice sheet. Arctic hurricanes. And when I was on the ice sheet previously-- We had some of these events. And we almost lost a huge dome blowing away, a hundred-mile-an-hour winds, this kind of thing. And, in this case, the procedure was that if we had a report that there was an arctic hurricane coming up at the ice sheet, we would brace the tent with storm poles, make enough water to survive 24 hours, and then be in full gear in the tent. And then, if the tent, we're holding the walls actually, if the tent collapsed, decided to collapse, you would have to grab hold of the walls of the tent and drag it up on yourselves and hold that for 24 hours.   (laughter)   Then, if the tent actually was ripped apart and blew away, then we had these survival bags that were strapped to the sled. I actually tested one of these bags. They wouldn't have worked.   (laughter)   The problem was, the idea was that you crawl inside the bag and then push the cargo up against the wind side to survive. And there'd be one person in each one of these body bags. (laughter) And the problem, though, was that the zip-- You needed to unzip a part of it to breathe, and the snow would have come in. And so you're trying to keep the snow in. And then, if that failed, we were to dig under the sled and survive under the sled, which I think would have worked actually. The other thing we had with us, we had Iridium phones to communicate, which worked all right, I guess, occasionally. But we had these inReach Garmin, inReach Explorer GPS units, which you could text with. And, actually, those things were your lifeline. So we had them strapped to our body the whole time. And some of the folks here are actually following mine. And they would notice that it stopped and stayed still for a long time because I lost it over the side when I was flying, piloting. Luckily, I found there was a reserve one there. But the idea of these GPS units you had strapped to you was that if anything were to happen that you needed to leave the sled, you could put down a waypoint and walk away and be able to find your way back. In that environment where there's completely white, there is no nothing, within, you can walk-- If you walk 20 meters away from the sled, suddenly the wind can pick up and you get a surface snow drift just blowing snow and it's a complete whiteout. And you can easily just walk off in the wrong direction. And so one day I was resting and suddenly the sled did stop and it was just dead quiet. What's going on? And I got up and I realized I was completely alone. I was completely alone on the sled. And I went up to the front, and it was a bit hazy and there were some footprints walking off into the distance. And I realized what had happened was that-- They should have told me-- They had to release the kite and they were chasing it. They were gone. And, actually, and this is something I probably wouldn't do again, but I grabbed some food, stuck it in my pocket, laid a waypoint, and took off. Yeah. And probably the reason being I probably should have stayed but I did catch up with them. We came back. But the reason is, I mean one of the hardest challenges of this kind of trip is actually inside your head. It was physically pretty grueling, at least for me, I shriveled up and everything else, but really it was more the mental side of it. And you'  And so the expectation, though, is that from now on we're going to see more and more shipping through the Arctic. I think this year there was a Russian oil tanker that sailed through the Arctic with a strengthened hull. They built a strengthened hull for the ship so they didn't need heavy icebreakers to make a channel for the ship. So every year from now on we're going to see more and more ship traffic, and eventually it becomes like a big highway. And then all the things that come with that: garbage and emissions. So I think from now on, at least for this soot, we're going to have more fires. Not every year. That's not how things generally work. But, generally speaking, there'll be more fires in the boreal forests. The Arctic tundra is probably going to burn more and more. And then there will be intense shipping through the Arctic. So we're on the cusp of a new kind of pollution era, I think, in the Arctic. And so the goal for us is to investigate that, and then relay our findings to policymakers. There are serious policies, international engagement in this area for ship emissions in the Arctic. They're ongoing right now. So I really apologize for the collapse, collapse of the system. I think I've got time, I might... Tom?  - You ready to go?  - Yeah, thanks.   (applause)