 It's one o'clock on Tuesday, March the 15th, 2022, so you must be watching Science at Soast. I'm your host, Pete McGinnis-Mart. Every week, we bring you young scientists from the School of Ocean, Earth, Science and Technology, streaming live on Zoom from beautiful downtown Honolulu. We try to focus on research that our young scientists are conducting, partly to show the excitement that is there in their research, but also the relevance that they have to here in the Hawaii community. And today, we have a really special guest, Fernanda Hendricks, is a researcher at the Schools Department of Oceanography. Fernanda, welcome. It's great to have you on the show. I understand you've recently been promoted from a post-doc position. So can you tell us what exactly your role is at the university right now? Yeah, sure. And yeah, first, thanks for having me here. It's very exciting. Yeah, I'm a researcher, research oceanographer at Soast and at Seymour here at the Center for Marine Recovery Oceanography and Research and Education. I do research in the ocean here around Hawaii. So, and I'm an oceanographer through and through. So I have been an oceanographer since undergrad and then went to grad school to be an oceanographer, then did post-doctoral studies in oceanography. And now I am a researcher in oceanography. So it's through and through. And your degrees, were they acquired at Manoa? Or have you come here from the mainland? Yeah, no. So I'm from Brazil. I live most of my life there. I did my undergraduate degree there in oceanography. I did a master's degree in Europe. So I've been traveling a bit. And then from my PhD, I came to the United States. I was in California for maybe eight years, maybe six years. And I've been here in Hawaii for the last four years. Oh, terrific. While you're surrounded by ocean, several thousand kilometers in all directions. So is Hawaii a good place to be an oceanographer? I mean, it's excellent. It's why I wanted to come here. This is a perfect place to be an oceanographer. Like you said, ocean all around. And we have the beautiful Hawaii Ocean Time series here just north of Honolulu. So it's really perfect as in terms of access to the sea. It's something as oceanographers we all strive for is to try to get to the sea and obtain information. So yeah, it's an excellent place. Great. And we heard Nick Olm on the show a few weeks ago. He was talking about ocean color. And he just hinted at today's topic, which is underwater drones. So I understand that you use this hardware on a regular basis for your kind of study. Maybe you can start off, Michael, can you show us slide one? And Fernanda, what is an underwater drone? Or how do you use them? Yeah, so like I said, oceanography relies on data. You know, we need to know information about the ocean. And there are several ways to obtain information from the ocean. And the most common way is to get a ship. And you put people on the ship and then you go out to see and you collect water and you measure a bunch of information from that water sample. But that's very costly. It takes a long time. It's very slow. So recently now there are all these underwater vehicles. They're unmanned and they are autonomous. So which means that they can go out to sea without a person, you know, and they collect a lot of the same data that we can collect from ships. So they are these big instruments. They are this little yellow one in the middle there, for instance, is an underwater glider. You can point out a little yellow one. It's a little torpedo shaped instrument and it has all these sensors attached to it. And you can deploy it from the coast or you can deploy it from a small boat. And this glider can stay in the water for months at a time collecting data. So you don't have to be present in the ocean to collect that data. So it's very exciting to be able to have those instruments to help us out and collect more information about the ocean for us. Sure. And when you talk about collecting data, can you give us a few examples of what measurements might be made? Yeah. If you talk to any oceanographer, the two main things you're ever going to collect is temperature and salinity. So how warm, how cold the water is, where, and how salty that water is. So those are the two very basic parameters. But these instruments are very sophisticated and they have all different types of sensors that you can measure. So you can measure oxygen concentrations, so how much oxygen is produced by the algae in the water. Or you can measure how many nutrients are in the water that are necessary for algae to grow. Or you can measure how much sediment is in the water. So there's all different types of instruments that you can attach to these amen vehicles to collect information. Okay. And all of these measurements, do they record them on a flash drive or do you get data in real time? Yeah. It's a beautiful thing. So most of these instruments that are autonomous, they can give us data through satellite. So you don't have to recover these instruments. You don't have to have a little drive inside them. So here you're looking at, yeah, the first one here, you're looking at a profiling float, which is another type of these underwater vehicles. So this is a profiling float. It is that it's two, it's about, you know, five feet long. And it profiles like the name says, it goes from the surface to about 2000 meters depth, sometimes deeper. So that's, I don't know your feet, but that's very, very deep. Sorry, I do everything in metrics. That's about 10,000 feet. So yeah. Yeah. And then whenever he comes back to the surface and as the little first drawing was showing there, it can send the data through a satellite. So it's like a phone, you know, phone connection. And then he sends all that information and he can download that from your computer. So every, you know, for, for, for most floats every 10 days or so, you will get a whole new profile of data and you can just access from wherever you are. So another beautiful thing about these instruments that you don't have to go out to see to get the data, they come to you. And then I think the third slide will show a slightly different way of operating this data. Yeah. Yeah. So the previous one was a profiling float. As the name says, it just profiles up and down and it drifts with the currents. This one is an underwater glider. As you can see here, it looks kind of similar to the previous one. It's also tube shaped, but it has wings. So the way it works is that it, it, it profiles the water column in a, in this sawtooth pattern. And I have a little, I have a little, little one here. I don't know if you can see. It just goes up and down in the water column like this in a sawtooth pattern. And it has wings. So it can kind of be maneuver a little more easily. But none of these instruments, they all, they don't have propellers. They don't have motors. They all rely on just changing. So they have bladders. I think the next slide maybe has an example of how what's actually inside of these instruments. So on the bottom there, the little yellow part, there's a bladder inside there that inflates. And whenever it inflates, it makes the float go up to the surface. Whenever it deflates, it makes the float sink. So just by doing that over and over, you can profile the water column. So just explain a bit more what it is we're seeing in this slide. The left-hand image is presumably someone throwing it overboard and throwing it carefully, presumably. But, but we're seeing these cutaway diagrams of what the, Yeah, this one, yeah, this one is really cool because they, they, they made these diagrams to, to make you look like, like they're transparent so you can see what's inside. But they usually have this yellow shell around it. And on the left there, you can just see the size, right? Like it's about the size of a person or so. And you can, yeah, you can throw it from, from the side of the ship. Some people actually throw it from aircraft. So they're pretty adorable little things that you could, there are many ways to deploy them. But then those, those diagrams there on the right, they're just showing you what's inside the float. So there's some batteries. There's that bladder that I talked about is on the bottom that inflates, that deflates to help the float go up and down. On top there, more on the right, you can see there's the, there's the antenna that, that helps you connect to the satellite and gives you the GPS position. So the latitude, longitude and time of each profile that you're collecting. And there's, there's also some snapshots of some of the, the sensors that you can collect or, or, or, or that you can attach to these profiling floats. So there the CTD is a conductivity temperature and depth sensor. And that's what's going to give you the temperature, the salinity measurements that I was explaining before, which are really basic for oceanography. There's also an oxygen sensor, the O2 there. There's an NO3 sensor, which is a nitrate sensor. So the all types of different sensors can be just attached to this body. And these are battery powered. We've had discussions of wave energy on an earlier show, but these sensors rely on batteries. So there's a battery run out of power. Is there any way of recharging it? Or do you have to go and pick up the sensor? Hopefully you can reuse it. Yeah, that's one of the, the tricky parts. So yeah, there's, they're all battery powered. So either alkaline batteries or lithium batteries, for most, most floats that are up there, they last between three and five years in the ocean. And then after that, the battery dies. So depending on where in the ocean the float dies, you can't really recover it anymore. But gliders, for instance, because they have those wings and you can maneuver them, as soon as you see that they are going down in battery, you can just, you know, bring them back to coast and then you can collect them again. Do you have any idea how much these things cost? I mean, are they millions of dollars or thousands of dollars? What order of magnitude? How much does one of these drifters cost? Yeah, so there's a huge range. So for a very simple one that has, you know, a temperature sensor or a salinity sensor and maybe oxygen, you're looking at about 25,000 per float. But it can go up to, you know, 80,000, depending on how many instruments you're attaching to it. Now the glider, the one with the wings, they're a little more expensive because they have a little, you know, they're a little smarter in a way that you can maneuver them. So they, they have a little more juice inside. But those can be, you know, around $100,000. So they are not cheap, but compared to, you know, how much it would cost to go on a ship and collect that information, like a ship day sometimes can cost $40,000 per day. So, you know, from one instrument of those, you can actually get a lot of information and you don't have to go out to sea. So That's nice. Now, do we build them here in Hawaii or are these commercially available? They are commercially available. There are a few, a few companies that sell them, mainly in the U.S. and in France. They're the two main regions where you, where you can buy them. But universities develop them. So the University of Washington has a big program for that. So we, we, we partner with them a lot to, to look at floats and gliders, but they are commercially available. Yeah. And I would imagine just building one of the instruments might be something that we could accomplish at the University of Hawaii and, you know, put it on somebody else's drifter or the gliders. Is that them? Is that them? Yeah. So we can definitely attach our own own instruments to it. The only tricky, the main tricky part is that we need a big tank to test them. And then sometimes that, like, you know, universities don't have access to a big tank where you can dump them in the water there. But I think here, you know, the tank is what you mean. Like a big swimming pool where you can, you know, sink the, the, the floats and check if it's properly balanced. And so that sometimes takes a little more infrastructure than the most universities. We've got the pool down in the quality. I mean, that's an opportunity, I thought. That's true. That's true. But I think, I even think here, they have a, they have a program or a few years ago where they were trying to develop really cheap autonomous vehicles. So there are lots of, you know, even as like grad school projects that you can deploy a little, a little like both surfboard with instruments on it and have it go somewhere. So there are ways to make it cheaper too. And, you know, especially if it's for coastal applications, which is a little closer to home here, if you don't have to, you know, to have the thing go super far away, there are definitely cheaper ways that you can do it. Right. I think your fifth slide really surprised me if we can take a look at that one. You know, I was quite impressed by the number of measurements that these autonomous vehicles, these underwater drones can actually collect. It explains to the viewers, you've got two global maps here. The gray areas are land masses, right, for the viewers. Okay. Yeah. So on the left here, you're looking at, you know, if floats did not exist, if none of these autonomous vehicles existed, that's every little dot there. They look like lines where they are little dots. They are each location where a ship one day has been to collect some sort of data. So the black colors is, you know, up to 10 measurements and the purple color says, you know, more than 200 measurements. So you can see there that, that, you know, over the whole history of us collecting data in oceanography. Most places in the ocean, they only have one to 10 data points. And they, you know, they are changing over time. So if we only have one to 10 data points in time, that's not enough to understand what's really happening in the ocean. But then with these, these deployments of these profiling floats and gliders and other autonomous vehicles, we have been able to extremely expand the amount of information that we get from the ocean. And that's on the, on the right there. So those are the little dots of, you know, data obtained from profiling floats and other autonomous vehicles. So it's huge amounts compared to what we can do with ships alone. So would it be correct to say you're looking at these two diagrams? There were a few data in 2018, but the vast number of colored dots in the January 2019 image is actually showing that this huge development of underwater measurements from, from drones. Would that be representative of where we are today? Or is there in fact a similar increase in number of data points being collected year after year? Yeah. So there's a program. So the Argo program, they aim to have about 4,000 floats at any time in the ocean. So that would mean, you know, one float every 200 kilometers in the ocean, more or less. And they have reached that goal. So every day, you just, you know, every year, you just keep putting a little more floats just to, you know, some of them die and they just replace them. So that's about 150,000 profiles per year that we get. But there are other types of floats as well. So the numbers are increasing over time. Yes. Okay. And so you're saying a few thousand of these floats at any one time in the Argo program, but each float might cost, let's say, average $50,000. So this is quite an expensive endeavor, right? So someone in Hawaii, you know, why would they be very interested in this sort of global data set? Wouldn't it be better just to concentrate the measurements closer to the Hawaiian islands, for example? Well, we are in the ocean and we are in the planet, right? That whatever happens here happens everywhere else. So if we all know about climate change, for instance, climate change is one of those things that we have been able to observe from profiling floats. They are measuring temperature and are measuring salinity everywhere. And from them, we can actually see how the water is warming up over time. And because of these profiling floats, not only have we been able to see that the surface of the ocean is warming up, which we have been able to see before from even from here from Hawaii, but also the bottom of the ocean is warming up. So that means that the entire, you know, ocean system is warming up, which is pretty serious. And, you know, what happens when water warms up, it expands and that means sea level rise. So, which is one of the reasons why sea level rise happens because of the expansion of the water, because of it being warmer. So we should all really care about where that's happening, because we are all affected by it. Last week, for example, Noah presented his analysis of sea level rise around Waikiki. And he touched on the fact that the sea level is rising partly because the ocean is getting warmer. You are able to provide that kind of information that even at great depths and presumably, you know, many hundreds, if not thousands of feet below the surface, the water is changing its temperature, as well as the chemistry. Has that been detected? Exactly. Yeah, that's perfect. Fine. And yeah, for instance, the pH of the water, right, how acidic the water is, we've also been able to measure from these floats that the water is getting more acidic because of the extra CO2 or carbon dioxide that's been added to the ocean because of burning of fossil fuels. So we have been able to monitor all those changes, all these autonomous vehicles, you know, throughout the entire ocean. And you do need to have all of these data everywhere to be able to really see what's happening in a global scale. Okay. And viewers will hopefully see a future program where we're actually looking at the impact of changing acidity on coral reefs, which of course are really, really close to home. So your studies are providing background information, not only on sea level rise, but indirectly on the health of coral reefs or the ability of coral to grow around the Hawaiians. Absolutely. You've got some other slides. Do we want to look at number six, which I think is an Argo diagram. I modified this, I put red dots on, this is early 2022 data set. What kind of map is it that we're looking at here? Yeah, so here, here we're looking at a map of all the, it's called the biogeochemical Argo, which before I talked mostly about the Argo program, which has mostly temperature, salinity, oxygen, which are more primary variables that we measure in the ocean, primary properties. And these red dots here are the complementary to that data set. So they have more complex data. So here you're looking at about 500 points more or less. And those are all the folks that have ever been deployed that have other instruments. So they are measuring the amount of sediment in the water or the amount of algae in the water or nutrients and pH. So there are less of those more complex floats in the water compared to just temperature and salinity. But still it's a lot. But you can see that some areas in the ocean are still, there's no information there. There are no floats in certain regions. Including between Hawaii and Alaska, there are very few of them there. And just for completeness, the colors, is that temperature or is that ocean color or what is the rainbow showing? Yeah, yeah. So the color in the background there in the ocean, so the whites are the continents and land masses. And the color is chlorophyll. So that's an indication of that there is the presence of algae in the ocean. So there are certain regions that you have, you know, more of those, some region you have less of those. Okay. And that's just a snapshot in time or that's sort of a monthly average? Yeah, that one is a monthly, no, let's see, it's a yearly average but just during spring. So we just pick all the springs and then you have the average. That's what it looks like. All right. And I think as we're a little short on time, let's jump ahead to slide eight. Okay. Which I believe shows a similar kind of data plot on a smaller area, right? Can you talk us through these gliders? I like it particularly because you've got changing days, right, to look at the temple variability. Yeah. So this is an example of how gliders can be used in very coastal environments. So here, these are little graphs of the white part there is the seafloor. So you're looking at the ocean from the side. So the white is the bottom of the ocean and the blue color is the actual ocean. And the color is going from blue to red is the amount of sediment in the water. So the redder it is, the more sediment in the water there is. And then what you're looking at is every day or so for a period of 12 days, I think it's a 12 day period, you can see how that section of the water changed. And this was during a storm, which is really, really cool because we can't usually put ships in the water when there's a storm, but we can put one of those unmanned vehicles. And this is just showing you how the water really changes as a storm passes by. Okay. So the vertical axis is depth below sea level. So sea level would be where each of the days. Okay. I would guess this is a really useful thing for people who are worrying about beach nutrition in terms of putting sand back on Waikiki beach or watering along the east coast of Oahu. You can really tell where the sand is moving around in that. Absolutely. And then also for biologists also want that because their organisms living on the bottom there who are affected by all these sediment moving around. So yeah, lots of applications. And there's day-to-day changes, right? Yeah. Between 1st of December and December 7th a week is completely different. Yeah. Yeah. Yes. We tend to think of the ocean as this big blue blob and there's a log going on underneath there and these things pop as check it out. And your last slide, slide nine, I think shows also just some of the experiments which you and your colleagues have been conducting north of the Hawaiian Islands. Yeah. One of these two diagrams. Yeah. So that's the Hawaiian Islands. The black lines are the tracks of the gliders. So these are the, I just picked the two last gliders that we've had here that were deployed near here. And there's a website there that you know people watching can go to the website and actually check out these data. So if you want to see what the water looks like around their region you just click on that website and you can see all these different properties. Right. I mean the diagrams themselves with the colors represent depths to the ocean floor. Okay. So obviously around Oahu and Maui it's relatively shallow and you send the the gliders around the deeper parts of the ocean. It looks like this monitoring station, station of Oahu, the red dot. Is that where a lot of the experiments are being done? Yeah. So we visit that station every month or roughly every month. So that's when we get the opportunity to deploy these instruments and you know much safer to deploy them in a deep area because we know we're not going to hit anything. But yeah and then we can because they have wings and they can be maneuvered you can send them anywhere you want. So if you see a cool feature you can just okay go check that feature and see what's going on in there. So the gliders are super useful for that. When you get the data in real time you might get several data dumps every day so you can respond to a condition. And viewers are looking at this I really would encourage them to take a look at this website. I went on a yesterday and I had great fun because there's lots of photographs of the pilots and I'm guessing that Fernanda you can't drive one of these things it needs special expertise. But yeah you need a computer and connect to the internet and then you can pilot them from far away. Oh really? So that's all that is needed isn't some kind of protocol but you know you have to be in charge of the research project there. Oh definitely yeah it's not simple so we have people here at SOS who do that and but it's simple in a sense that you don't have to be present there for it to happen or you can do it remotely. So that's very powerful. One final question. None of these drones have cameras on board. Has anybody thought about putting underwater cameras to take a look at say the ocean floor or look at organisms in the water column? Yeah that's a great question. There are definitely floats or gliders that have cameras attached to them. They are even these very special imaging instruments that can you know take pictures of microscopic instruments or microscopic organisms. So yeah those definitely says they're very expensive but it can be done. And I would imagine that the data rate would be quite high for an image particularly if it's a color image you need a lot more bandwidth to the satellite communications. Yeah the cool thing is that the glider you can recover so at least you can have it saved. Yeah I hope you can recover. Well Fernanda I'm afraid we've run out of time so I want to thank you again for being on the show. Let me remind the viewers you have been watching Science at Soast. I've been your host Pete McGinnis-Marc and my guest today has been Fernanda Hendricks who is an oceanographer and we've been hearing about underwater drones. So thank you very much for watching today and until next week goodbye from me and goodbye from Fernanda. Goodbye. Thank you so much for watching Think Tech Hawaii. If you like what we do please like us and click the subscribe button on YouTube and the follow button on Vimeo. You can also follow us on Facebook Instagram Twitter and LinkedIn and donate to us at thinktech hawaii.com Mahalo