Wisconsin Public Television University Place Wednesday Nite at the Lab  Luke Winslow The Worldwide Network of Lake Researchers  July 18, 2012 UP742  cc >> Thank you for watching Wednesday Nite at the Lab tonight. I'm Cassie Immel and I work here at the Biotech Center. This evening we'll have Luke Winslow from the Center of Limnology. Luke is a graduate student from the Center of Limnology from here on campus. He's currently working on his PhD with Paul Hanson and Emily Stanley. His current research areas include understanding the influence of physics on phytoplankton, a type of algae, and dynamics and understanding the extent and role of lakes at the continental and global scales. Luke received his bachelor's degree in material science and engineering also here at the UW. Tonight he will enlighten all of us on the Global Lakes Ecology Observatory program. So, without further ado, here is Luke Winslow. >> Thank you. 

[APPLAUSE] All right, as she said, I'm Luke Winslow, and I was all prepared tonight to thank you guys for braving the drought and coming here... [LAUGHTER] But apparently I have to thank you for braving the storm and coming here. So, I'm going to be talking tonight mostly about the latter half of some of my work which includes looking at what we've dubbed global limnology, lakes on the surface of the Earth and what they do. But a lot of it's also going to be about my story, and it's really going to be kind of a journey through what got me to where I am because a lot of science is about individual researcher's backgrounds, what our history is, where we came from, what particular experience we've had that brought us to the research that we're at. So of course I have to start with my hometown and my parents, who are actually here tonight. I'm from Darlington, Wisconsin, small town southwest of here. It's very famous. It's very famous for two things: the Darlington Canoe Festival and once Johnny Depp was in Darlington. [LAUGHTER] This can be still found on their website. It was a very big deal. 

These are my parents, Amanda and Jerry Winslow. I am the son of an educator, of a teacher, and of a mechanic, and you'll see how that crops up in what I do for the rest of my life throughout this presentation. And I also would like to note that although it looks there that they're avid downhill skiers, that was the first and last time they were ever in downhill skis. [LAUGHTER] Throughout my life I have been around technology and the outdoors in kind of a weird combination. And I realized, going through some of my old photographs, that I was either fixing something, building something, or outdoors was our primary activity. And so throughout my life I wasn't really sure exactly what I wanted to do because those things didn't necessarily mesh together. I knew a lot of biologists who studied biology but wasn't really in the technology realm. I knew a lot of mechanics, technologists. And so when I came to Madison I actually went into engineering. And I did material science and engineering. 

It was a fairly broad field. I was fairly interested. My senior thesis ended up being this semiconducting properties of pentacene, which is organic semiconductor. I won't go into details of that. It was an interesting project. While here as a student though, I have to say University of Wisconsin Madison has a phenomenal variety, maybe you already know this, but a phenomenal variety of opportunities. And one summer, I was looking for a job, I had previously been working at a Boy Scout camp many summers before, and I decided I want to do something different this summer. So I looked online at the UW Job Center website, and I saw a job advertised for the Center of Limnology, and I applied. And I got rejected. And so I saw another job from the Center of Limnology and I got it. 

And that summer then I did a lake survey going through almost 200 lakes in northern Wisconsin. The goal of the survey was to sample a random sampling of lakes. So you just take all lakes and pick randomly from them. And this is something that actually really had never been done before. Most surveys that had been done previous to that point usually have some sort of size cut-off. So what we ended up doing is driving down back forest roads, climbing through thickets. I actually had the opportunity that summer then, from walking through such dense overgrowth, to get both grass stains on all of my clothes and also in my crotch area, because it was so thick in that area. >> Too much information. [LAUGHTER] >> It was just, it was ridiculous. Anyway, I got asked then to stay on. 

I had, all through high school, I had a great deal of interest in computers and computing technology. So I was asked to stay on by my adviser, my now adviser, at that time boss, Paul Hanson, and to work computer support in the department which I thought was a fantastic opportunity. I also loved computers. And this is really where I started to learn that computing technology and the environment can go together. And I was then given the opportunity to, oh wait, sorry. So here I actually learned about many of the buoy and environmental sensing opportunities we were having at the Center of Limnology. So in 2007 I became what I call the professional buoy boy. I graduated from my undergrad here at Madison, and I got the opportunity to build and design environmental sensing buoys which was really a niche and very difficult to do at this time for lakes that we were studying. And so here is the University of Wisconsin Madison limnology buoy that's actually out at Mendota. I've been deploying this buoy for the last five years now. 

This is the fifth year that it's out there. If anybody's been out on the lake in the last five years, you've probably seen the buoy. At this point I have to mention, a lot of scientists put this at the end of their talk, but I want to mention that almost all of the research that you're seeing today was in some part funded by the National Science Foundation or private donors or the University of Wisconsin directly. And they do an excellent job, and they work very hard to make sure that the research they're funding is pertinent, is useful. It goes through multiple levels of review. It's very difficult to get funding. I say this because there's been recently some attacks against the National Science Foundation by various groups arguing that it is a waste of taxpayer dollars, but I want to say that it does phenomenal work and you must examine the research in a broader context. There was a specific example, and they actually parodied it in this commercial where they were looking at the speed at which shrimp could run, so they had shrimp on treadmills. But this was a much broader study to understand shrimp and what controlled shrimping operations and the yields of shrimp which is a very, of course, important industry. So these all have to be viewed in broader context. 

So, this buoy work in Wisconsin actually ended up spawning then the Global Lake Ecological Observatory Network. There are a few researchers who were at a conference, and they said, well, geez, you guys deployed a buoy, well we deployed some buoys too, and we don't know anybody else who has deployed these things so we should talk more. And the other researcher was a researcher in Taiwan, and this started a very small but very quickly growing network of researchers who were interested in doing this thing. You can see it was connected between Wisconsin and Madison and also the northern point is the North Trout Lake Research Station which is the limnology research site which is the Northwoods in the main lake district in Northwoods Wisconsin. And this quickly grew. These were some of the very first buoys that were ever deployed. The buoy was the buoy in Taiwan on a lake that we'll see more pictures of later, a very interesting lake that I'll talk about. The yellow buoy is a lake on Trout Lake which is a very big and very iconic lake in northern Wisconsin that I know a lot of people are familiar with. And the third buoy there is actually then a buoy on a less known lake, of course, but can be, and we'll talk about this later, may just be just as important to the grand scale of things. This is a very small lake that we've dubbed Trout Bog. 

It has no name. There was nobody living on it. It is a lake that is about the size of this room, but it can have very important, very big repercussions to the grand scheme of things. So, then through this involvement I had in GLEON, I first had the opportunity to go to Taiwan and go to YYL. I always call it YYL because I'm not very good at Chinese. But it's Yuan Yang Lake, I've slaughtered it I'm sure, and this is a really phenomenal lake. This is a lake in the mountains of Taiwan. A lot of people don't realize Taiwan is a very, very mountainous country, actually. The majority of the people live on the western side of Taiwan, but actually the eastern side is all mountainous region. And this is in the middle of the mountains. 

You can see these very steep mountains around the lake. And what happens is that Taiwan gets hammered every year by typhoon after typhoon. It's not uncommon to get hit by two, three, four typhoons, what we would call hurricanes, in one year in Taiwan. And this lake, when that occurs, is small but in this very deep valley so it gets an absolute ton of water. This water rushes down the sides of the walls of the mountain, rushes into the lake, and what this is is this is a thermal profile from the lake that we could have only gotten by having the buoy and an automated sensor package out there. We can't go out there in a typhoon. When a typhoon hits, this lake doubles in depth. So it goes from being a four-meter deep lake to an eight-meter deep lake. So this is the normal depth of the lake. Imagine four meters higher. 

So it becomes a very dangerous place, but the buoy survives this and you can see in this temperature profile what will actually happen is this lake is resetting. Normally a lake is, most lakes are a stratified system. The top of the lake is very warm; the bottom of the lake is cold. Mendota is like this. Lakes in the Northwoods are like this. Lakes in the Arctic for periods of time are like this. Lakes in the tropics are like this. They often have this stratified layer. In this typhoon, so much water rushes through, it resets the lake. So we can kind of view this lake as a test bed, and we went there one summer to look at it. 

And also for reference, the total amount of rainfall that fell in those two days in this example was almost a meter of rain. So you can think of it as maybe 30 inches of rain in two days. So a very large amount of rain. But, of course, that kind of work is not always easy. This is the road leading back to civilization from the lake. This was the year before I was there. This typhoon doesn't just bring a flushing of the lake, but it also brings major catastrophe to infrastructure and roadways. So it can often be interesting going to these places. I also ended up, we also then, as this network grew, we found partners in Argentina, a group looking at various lakes in Argentina. Beautiful country. 

So we got to go and visit this incredible chain of lakes, which I've never heard of such a situation before, where in the span, this lake chain, from the top point to the bottom point is perhaps 100 miles, and this lake, Alcina, is almost purely fresh water. And as you move down the chain of lakes, one lake drains into the other lake and they become more and more saline to the point where Epiquin, the bottom lake, it does not have an outlet so all this salt just comes and collects. It collects in this bottom lake, and it's a very, very hypersaline lake. It is, I think, over four times the ocean, but don't quote me on that. You can actually see here, this is a picture of the lake. This is us doing work on the lake. Because it has no outlet, then it also has no ability to regulate its depth. So there times in history when the lake was much shallower and these trees grew, and then these lakes became much deeper and all these trees were killed. You can also see here at the bottom, there's actually salt precipitated out from evaporation. Every time a wave comes up, that salt sits there and it grows and it grows. 

That's how salty this lake is. And of course then the very salty, the famous Dead Sea. This is actually fairly recent. This is only two years ago that I got to visit the Dead Sea, and I can be honest that I came into it with not that much interest. I thought, oh, the Dead Sea, it's very famous, it's very salty, whatever, it's cool, people swim in it. But if you ever get the chance, wow. This is us in the water. Just with our hands out we are floating in the water the way you see it. People would hold rocks above their heads because it's so buoyant. You're just like a cork. 

But the disadvantage here is when I got in there's salt precipitated on all the rocks. It's very sharp. It's very jagged. I, of course, slipped, scraped by back, and then after scraping my back I get into hypersaline water, and I had a giant red patch that hung around for the next week on my back. So beware. There's also the very clear lakes. Lake Tahoe in California and in Nevada. It's on the border between California and Nevada. Lake Tahoe is an incredible example of an alpine lake, an especially big one in this case, but an alpine lake that is extremely clear. It gets very little nutrient input, unlike, say, think about Mendota. 

Mendota we have an agricultural region, we have a lot of nutrients that flow into the lake. They fertilize a lot of algae. Lake Tahoe is the opposite, and Lake Tahoe is incredibly clear. Lake Tahoe has actually, I think it's lost something like half of it's clarity in the last 50 years, but it's still, you can still see a disc this big 26 meters down in the lake. So 75 feet more you can still see a disc as you lowering it down in the lake. It's an incredible lake. And that's even after losing some of its clarity. So very, very interesting world. The buggy, this is a lake in Iceland. I have a colleague who's actually an entomology student who's been doing work on this lake, and I got the opportunity to visit last year. 

And this lake is literally, in Icelandic it means midge lake. Now, I came last year and I saw it and I thought, oh, cool. It's a nice lake. It's a very interesting lake. It has a very high phosphorus load. It actually has a very natural, it's a naturally eutrophic lake. So, like Mendota, lots of algae but not due to agriculture, not due to anything like that. It's actually geologic. It has a cold water input which brings phosphorus in which is coming right out of the rock it's so volcanic. And then there's a warm water input which is very warm. 

It's something like 75-80 degrees all year round, and it brings in nitrogen. And these two inputs come into the lake and they merge and they create these huge algae blooms. They fertilize these massive algae blooms. And what happens then is that midges, which are the small, they have a larval stage which is a worm that's in the bottom of the lake, they feed on this huge algae bloom and they do this. And this is a midge emergence. So this wasn't the year that I was there, but this is several years before. There's a midge emergence where they form clouds. They're known to blacken the sun as a cloud passes by the sun. They form these outrageous, it is probably one of the largest midge emergence in the world. And even more interestingly, and one of the things that the researchers are very interested in in this system, is they're cyclical. 

This is the year I was there, and this was three years before it. And this happens year in, year out. It cycles. Seven years, six years, five years, and they still don't fully know why. Of course while I was there I had to get a sweater, and so here's me in the outrageous Icelandic sweater. And, of course, lakes that are actually very close to my heart, which is the tiny, the very small lakes. This is a small lake. All these small lakes, all these names, we've given them to them. These are not official names. None of these small bog lakes have names. 

But we call this Timber Bog, and this is a small lake probably even half the size of this room. That's a canoe. If you put three canoes end on end, you could walk across the lake. And this is in northern Wisconsin, and there are millions of these out there. They are everywhere. There is absolutely huge numbers. And this is really where a lot of the interesting research in global limnology lies because big lakes we know a lot about. We can go once to a big lake and we have good idea of what it is. And there are, potentially, something like a thousand to two thousand lakes over ten square kilometers in the world. But these small lakes you'll see later, there are absolutely millions of these, and they're much harder to understand. 

So, as I was saying, these lakes are all part of the Global Lake Ecological Observatory Network. These have all been, in one way or another, studied by colleagues in our group. One of the central tenets of the group is data sharing, expertise sharing. The idea is that, as with lakes and with lake researchers, we have to combine our efforts, our resources, and our data to answer bigger questions in the world. And this is actually a fairly outdated map. There are a lot more groups that have now joined the network around the world. I bring up, so, as I said, a lot of where I started was in buoy work, building instrumented buoys, and so, in some way, my kind of capstone project of that before I started my graduate work, which I'll talk a little bit more about, was the profiling buoy. This was a buoy we built to take an instrumented package where it would sense things like chlorophyll, blue-green algae, and index of blue-green algae, temperature, dissolved oxygen, and it would raise it and lower it in the water column. And this is much easier said than done, I assure you. You have a contraption to raise and lower something and then you have waves and then you make it solar powered and then things grow on it and it's definitely an engineering challenge. 

But a good friend of mine, Jordan Reed, who is unfortunately not here tonight, but him and I decided to take on this challenge and build it. And we actually made the front of the Wisconsin web page for this deployment in Lake Mendota. We were all very proud of ourselves. This here, as I said, this is Jordan. This is myself. When we went to the front page of the Wisconsin website, I was mentioned and Jordan's legs were on the front of the website. It wasn't quite what we were going for, but it was still very nice to have. So, you might be asking, what are these buoys doing? I gave that example in Taiwan a buoy can help you see what happens to this typhoon. But lakes are extremely dynamic and interesting systems. With these sensing platforms we get a much closer view of what's going on physically and biologically in the lake, and here's an example. 

This is Lake Mendota and Mendota is a big wild lake and it gets pretty windy out there and it can do really crazy things. So what you're actually seeing here, up above this is that temperature profile, and, as I said, this surface water is generally very warm. Ignore these blips. We were having some sensor difficulties at this time. This is the surface water. These are deep waters that are very cold. And this here then is a large wind event. This is very strong winds coming into Madison a single direction. They have so much strength they take this cold water which is more dense in this warm water on the top and they actually push the cold water to the side. It sloshes the lake to one side because there's so much force to one direction on the lake. 

You can actually see that with these buoys. And then, actually, as it recovers, you get these waves that continue to propagate through the water column. We can also see, I'll say, how the lakes breathe. And just like we do, just like we need to do, we tend to take in oxygen and breathe out carbon dioxide. Now, lakes do that in very much the same way only, of course, they also photosynthesize. So they have an extra nuance this. So you can actually see here's an example from a lake up in northern Wisconsin. This is the lake breathing. When the sun comes out, photosynthetic organisms start to photosynthesize. They take up CO2 and they release oxygen. 

This oxygen is coming out into the water. We can see it in dissolved oxygen in the water. As sunset hits, you can see that decrease again. So then this is all the other organisms, the fish, the bacteria, and even the algae they need to survive overnight, this is them taking in oxygen just like we do. Here's Mendota actually just moments ago. I regenerated this graph just before I came. You can again see increases, and there's a lot of interactions that are very complex with physics and the movement of water, but on a good day you can see a strong increase during the day and then a decrease at night. There's a very good day again. Strong increase, strong decrease. We can see that as it happens. 

And this long-term trend is actually the water heating up because warmer water holds less dissolved gas. So this is actually the water heating up these last few days that I'm sure you're all aware of. It's been hot and the water has warmed up accordingly. So, this is my story of course, as I said. I started undergrad here doing some work during the summer. I got to do this buoy work. I got involved with GLEON all, I have to say, thanks to my adviser and the people at the Center for Limnology. What did this do? Well, this work really broadened my perspective on the world. I saw lakes that were unlike our own, lakes I never thought I'd see, environments and biomes that I would have never experienced otherwise, and this is just a map of some of the countries that I've traveled through on my own or via work that I'm quite proud of except for the fact that at this scale it's not very impressive. [LAUGHTER] Europe just doesn't pop out like you'd think it would. 

And so coming back and starting my grad degree then, I wanted to go bigger. I wanted to take a bigger perspective on lakes in the world, and this was, as I said, I did a lot of software development, actually, as an undergraduate, and this has come back time and time again. I've used my ability to program and to develop software to create tools that researchers and myself can use. This is an online tool we call Lakebase. The goal of this tool is to index every lake in the world and collect any information we might have about it. So this is a growing collection of upwards of right now I think 10 million lakes in the world and any information we have about those lakes. You can just see this is, again, a shot of northern Wisconsin that is centered on our Trout Lake Field Station. These are lakes in the area, and each point is a lake. So there's a lot of lakes. And why do we care? As I said, lakes breathe and we take in oxygen, we release carbon dioxide. 

Just like that, lakes are doing the same thing. They're releasing oxygen, taking in carbon dioxide during the day. At night they're taking in oxygen and releasing carbon dioxide. And they are everywhere in the world, and they're part of this big global cycle of carbon. And here, of course, is a fairly classic, I'm sure many of you have probably seen a figure like this before. This is showing carbon dioxide concentrations in the atmosphere, or sorry, this is temperature, this is global temperature. But this is what we're looking at in terms of climate change and global warming due to increased CO2 concentrations in the atmosphere. And the big question here, and I have to say I don't have the historical perspective that some of the older scientists do have, but this challenge in recent history and this issue that's going on has really opened up a world of science that has said, whoa, we don't know how this works. We don't know where all this carbon is going to and where it's coming from and how these processes that put carbon into the soil, that put carbon into oil, into carbon, we don't know how these work. We don't know the rates. 

We don't understand the sensitivities. We don't necessarily know with a high degree of certainty what's going to happen. And so this has been a huge growing area of research, and you'll see it for, I'm sure, the next many decades still. But, of course, I'm interested in lakes. You'll notice this is a very classic carbon cycle figure. Like you've probably seen your water cycles only this is the movement of carbon through the ecosystem. So we have fossil fuels, we have people outputting carbon, we have carbon that's sitting in the atmosphere, we have it going into trees, into the soil. This is the ocean portion. We're saying how much is going into the ocean, where's it going in the ocean. Whenever carbon goes into the ocean, some of it might make it to the ocean floor and kind of disappear for a period of time, or some of it might get thrown back out into the atmosphere. 

There's a lot of variables here. There's a lot of different things going on at once. If you'll notice, though, this figure doesn't have lakes, and it doesn't even really have rivers. There's a small term here that's going to forests or something, and there's nothing coming out of this river. But this is probably where we're probably missing something. When we focus only on the ocean, on grasslands, and on forests and on human impact, we're probably missing some big pieces of this puzzle. Lakes are small, very productive environments, and so there's a lot of questions this brings up. What kind of role do lakes play? How much carbon are they bringing in? Or are they releasing excess carbon? Are they taking carbon from this term here that's coming into forests and are they putting it back out in the atmosphere? We call that net heterotrophy. Are lakes a source or a sink for carbon dioxide? Many questions and we have only a few answers. As I said, there's a lot of big lakes, and there's even more small lakes. 

What do these small lakes do? How much do we even know about these small lakes? Many of them, millions of them have never been visited by a researcher. Many of them we don't even know basic numbers about them. Many of them are actually too small to see by satellite imagery. We'll see that here in a bit. And of course you can make the comparison too. Ocean is 71% of the Earth's surface area. Land is something like 28%. And then lakes and rivers are probably around 1%. You say, okay, well, 1% isn't a very big number. Do they really matter? But they probably do. 

The ocean, while it covers a really big portion of the world, a lot of the ocean isn't doing much. And they call this ocean productivity map. And this is based on satellite imagery. And what they're doing is they're trying to measure the amount of chlorophyll that's in the water. So what you're seeing here is the red zones are hot. These are where there's a lot of chlorophyll, there's a lot of productivity, there's a lot of biological activity in the ocean. The areas where it's blue and purple, it's very low. The ocean, in many regions, is a big desert. There can episodic events where they get slightly higher concentrations, but there's very little going on in much, much, much, much of the ocean. So we can't really think about the ocean purely as being 71% of the Earth's surface area. 

It's not just how much surface area you have, it's also what you're doing with that surface area. And the ocean, for a large part, in many parts is not much. Now, of course, the ocean is huge. I'm not trying to downplay the ocean. It's a very big part of this. But it's not necessarily as big as one might think. So what role do lakes play in this grand scheme? And I'm not going to come out here and tell you and answer. I apologize. This is an ongoing area of research. This is something that some people have made some estimates on, but we are still struggling with some actually very fundamental questions that get at this, and I'll talk some more about this. 

But one of the things that we first need to know to answer what role lakes play is how many lakes do we have? How much surface area is there in lakes? How much volume is there in lakes? How productive are they? How much photosynthesis is going on in them? Are they sources or are they sinks? There's a lot of questions that are bound up on this. And something that I've been researching then, I'll come back to this, something I've been researching, and I'll get into this in a bit, I've been researching and trying to figure out how we can understand the number of lakes and the surface area of lakes on the globe. And why do we need to know this? Well, we need to figure out a way to start to estimate these very important things at broad scales. We need to figure out, okay, well if we don't know what lakes are doing, well let's figure out what one lake might be doing and then multiply it times the number of lakes. Well, we can't exactly do that because there are small lakes and there are big lakes and then there are really, really big lakes. Here's a figure that doesn't come out super well, but this is the surface area of Lake Baikal, this is the surface area of Lake Mendota, and this is the surface are of Trout Bog. And, actually, on a log scale in square meters, Baikal is closer to the surface area of the Earth than it is to the surface area of some of the small lakes. So lakes span a huge gradient. This is actually, this faded outline here is Baikal, and this small dot here is Mendota, just to give you an idea of the scale that we're dealing with. So, how do we look at this? How do we start to take this weird collection of big lakes and small lakes and medium size lakes and start to make sense of it? Well, a researcher named, very famous researcher in limnology named Robert Wetzel, Bob Wetzel, in 1990 basically first proposed the idea of just looking at patterns in lake size. 

And he took a very simple look at it, and he said, okay, let's look at each lake area size class of lakes, so lakes that are a thousand square kilometers, a hundred, ten, so on and so forth, and let's look at how many of those lakes there are. Now, this is a figure he kind of drew up. This is a theoretical figure, but he theorized based on what he knew and based on what he found at that time that this followed a regular pattern. This is what's commonly known as a power law, or if we're thinking about spatial statistics it's often called a fractal process which means that there is a known, if you know the number of a big thing, if you know there are 10 lakes that are 1,000 square kilometers, then there's probably 10 times as many lakes that are 100 square kilometers. And there's probably 10 times as many lakes then that are 10 square kilometers. And you can start to make this kind of assumption of a process of a model and use it to estimate globally. We can count the number of large lakes, and we'll see here in a second. And this actually hinges on a very cool thing, a very cool kind of fractal nature of geology, fractal nature of the universe. Let's not say the universe but geology on Earth. And you can take, actually, a very simple process that scales many sizes, it can act on inches, on kilometers, on miles, and if you create this fractal theoretical surface, like this one here, you can see here. 

This is a theoretical fractal surface that I've created. If you take this and you just pretend, let's say you dump water on this. Of course we don't do this in the computer. It would not be good for the computer. But you can theoretically dump water on it, and you can see where lakes form. Where do they pool? And what you get is a surface that looks like this here. And actually then, if you take and, just as we did here before, if you plot the number of lakes at each size, then you get this relationship. This is size and this is the number. This very linear relationship again that each time you go up in size class, you get 10, you get a known number more of these lakes. So we can go on and we can say, okay, if we know this and we know the large lakes, we can see the large lakes from space, they're fairly easy to identify, there's not many of them, and this was work done where they indexed, they took satellite imagery, and they looked at all of the large lakes and all of the large wetlands in the world, and they released this phenomenal data set. 

And if you take this portion of the large lakes you have, you can see here it actually only goes down to 10 square kilometers which is just a bit under the size of Lake Mendota, and you then extrapolate out, you go out this knowing that relationship is steady into the small lake size classes, you can start to estimate how many lakes there are in the world. And I wouldn't be a researcher up here talking unless I talked about some literature. So there was a very influential paper that was published, and this gets cited all over the world. Downing et al, 2006. He's actually a researcher in Iowa, I think Iowa State, I forget exactly, and he then estimated from this relationship how many lakes there are in the world. And he said a lake stopped at a 10th of a hectare which is 100 square meters which is not very big. It's probably a tad bigger or it's a tad smaller than this room. If you think about 10 meters on a side, that would be 100 square meters. So that's the cutoff. No, I did that wrong. 

Sorry. Sorry, a 10th of a hectare is 1,000 square meters. So 23 meters on a side, something like that. So it's not a very big site class. Nonetheless, he estimated there were something like 304 million lakes in the world. And the vast, vast, vast majority of that, because of the way this relationship works, the vast majority of those are small, small, small lakes like those little bog lakes I was talking. Like your backyard pond, things like that. So my work then I wanted to see, his was all theoretical. He took that relationship and said, okay, theoretically, how many lakes are in the world. I took a recently released data set from the United State Geologic Survey, and I have to commend them on their phenomenal data sets. 

They are par none in the world in terms of understanding how the water and the land resources in a country, the US has done a phenomenal job and much of it has been done by the USGS. But I take this very large data set that they had released, extracted all the lakes from it, and then started looking at what kind of distributions of lakes we have in the US. It's actually very revealing. You can see the darker the red colors are a high abundance of lakes. The blue is much lower abundance of lakes, if not zero. And of course the southwest has very few, not surprising. But, actually, this southern central Midwestern region really pops out. There's a lot of lakes in this region. Now, it turns out, though, we have to be careful because just the number of lakes, as I said, number isn't everything. The abundance is deceiving. 

These lakes in the Midwest here are small, small agricultural ponds. Millions of agricultural ponds that have been built to water livestock and things like that. If you look at the surface area, the percentage of surface area that's covered, the figure looks completely different. I can show you again. Here you can't even see the Northwoods of Wisconsin, and Minnesota looks a little hot but not really like there's a lot of lakes. But here, again, you can see this northern lake region really pops out. Minnesota, again, really striking and even further west you see hundreds and thousands and thousands of lakes. Florida, actually surprisingly, I have to admit I have probably a Wisconsin bias, but Florida is an extremely lake-rich region as well. And of course Alaska. That is something that has been known for a long time. 

But one of the incredible statistics that came out of this then is that looking at this, if you break it up by state, if you say, okay, how many lakes are in a state, Texas has around a million and Alaska has around a million. But, again, in Texas, this is this region here, there's this agricultural pond building, and in reality, the actual surface area in Texas is much lower. So if we're thinking about the total surface area lakes in the world, then Texas doesn't pop out quite as much. Now, back to that relationship. So, Downing had said, okay, it goes straight on all the way through into small size classes. This is the work, this is looking at the actual data set from the USGS, and you can see this blue line is the line that Downing et al basically used in their results. This, the black dots here that basically look like a thick black line, that's the actual data set. That's the observed lakes in the US. And you can see it doesn't quite make it quite as high as Downing had originally estimated. And on top of that, it starts to deviate away in these small size classes. 

It's not longer a straight line. Now, that straight line makes sense in the fractal world like I talked about, but it's not clear yet what's going on to deviate this line downwards. It's an area that I'm actively working on right now as part of my PhD thesis, and there's a lot of potential issues. We might just not be seeing these lakes. They're very small, and satellite imagery is not perfect, especially in forested areas and things like that. You don't always get great shots of these lakes. We may not be hitting them all. These small lakes, they're very small. They may just evaporating. In dry areas, there may be the potential for the lake to exist but they may just be evaporating away and not actually existing. 

They may not have enough water supply to keep them in existence. And then in this large size class I just highlighted, this is a known issue. This is kind of the idea that we're simply not on an infinite plane so we can't have infinite sized lakes. In a perfect world, it would go out further, but we are constrained to the size of the world. So, anyway, yeah, as a quick synopsis, the original estimate said in the US there would be, say, 20 million lakes. Here are the estimates. My estimate based on the work that we've done says probably about 10 million, but of course because that change in the number is up here in the very small lakes, as I said there's a lot of small lakes and a well-known number of large lakes, it doesn't really change the amount of surface area a whole lot in our understanding. So that's something to kind of take away. Another little tidbit you might be interested in, unfortunately Minnesota still wins. Even if you look at all of the lakes in Wisconsin and all of the lakes in Minnesota, Minnesota wins both in number and they have about the twice the surface area as us too. 

So we can leave that to rest. There's no way. There's been lots of debates. It depends on if you look at named lakes or unnamed lakes, but either way they, unfortunately, win. Yeah, so this is kind of where my research is sitting right now, taking a look at broader scale. The next step is to understand kind of more, use more of a theoretical underpinning. What does this huge scaling of lakes, these lakes go from being the size of the state of Wisconsin almost in Lake Baikal to the size of this room, what does this mean? The lakes of this huge magnitude can't operate and can't behave the same way that a small lake does, and what can that tell us about our understanding of lakes as is? Another area I'm looking at is that lakes are not just their surface area. Historically in our field, we've looked at the surface area of the lake and we've added it up and we've said that two small lakes kind of means the same thing as one big lake and so on and so forth. But a lake is also its volume. A lake is also its perimeter. 

Things fall into the lake across its perimeter, carbon and leaves and things make their way into the lake. The volume of the lake has processes like respiration and it has thermal processes, the thermal mass of the lake is dependent on its volume, and of course then the area which we've thought about a lot. But expanding these notions to broad scales is part of my work also. And, of course, understanding and integrating these lakes into global models. Understanding how they behave, understanding what they do when we look at the globe, and so forth. And lastly, a personal interest of mine is also direct public engagement. It's why I'm here today. Tom had asked me to present, and I was more than happy to because I've really learned that science is nothing without communication, and I think that scientists in the past 20 years, 30 years, have done a not phenomenal job with actually direct public engagement and communicating what they know to the broader public. And so I'm interested, I'm very looking forward to if there's any questions after the talk here. And I've been working also with programmers and, of course, myself, as I've programmed, to build more better websites and better outreach tools that can engage a broader set of people however they want to be engaged with the science. 

I'm really open to the ideas. But this is just an example. This is an iPhone and Android application that you can get the Lake Mendota buoy data from, and it's turned out to be a huge hit with the sailors. For some reason they like to know what the wind is or something. [LAUGHTER] It's proven to work very well. And, as I said, I've been dealing with the Lake Mendota buoy, and so I have been blogging. If anybody's interested in the trials and tribulations of running a buoy on a lake like Mendota, I'm happy to take any questions or considerations in that part. And it's on the web if you want to look. There will be a link based on the Wednesday Nite at the Lab website. So, are there any questions? [APPLAUSE]