Gliders gliders everywhere!!!

It's been crazy busy working in the glider lab getting 5 gliders refurbished, tested, prepped and ready for deployment! Two of those gliders will specifically be used for our research project off the west coast of Australia. Let us give you a little more info about the 2 different types of gliders we're working with!

As we mentioned in our last post, there are currently 3 main types of gliders, though there are several others that exist (they make up a minute percentage of gliders in existence). Of the 3 main types of gliders, 2 of them are the most widely used type, and are arguably the most advanced and proficient models. These are the two types of gliders we are working with!
One of these types is the Teledyne Webb Research Slocum Glider (see image below). These are the type of glider we own and operate at the Institute of Marine and Coastal Sciences (IMCS) at Rutgers. They come in different models, which are meant to operate efficiently in a given depth range. There are 50-meter, 200-meter, and 1000-meter models; effectively shallow, intermediate, and deep gliders, respectively. The number of meters defines the maximum operable depth each particular model can function in without being crushed by the surrounding pressure, as pressure increases greatly with depth in the ocean. Base-model Slocums cost around $120,000 each. We have over 20 of them at Rutgers. We've lost 7 🙁 but we've flown well over 200 missions! Considering how new of a technology this is, and how much Rutgers pushes the bar with our missions, that's a really good rate. 🙂



The other of the 2 types is the iRobot Seaglider (see image below). iRobot happens to be the company that makes that little autonomous disc vacuum that vacuums your floors all by itself (it's called the Roomba)! They make many different kinds of robots, many being military and maritime grade robots. Unlike the Slocum glider, the Seaglider comes in one model that is rated to 1000 meters. The base-model Seaglider costs around $140,000.

Sounds like a lot of money, right? While obviously it is, in respect to other methods of oceanographic sampling, it's rather cheap! Or to use a better term: COST EFFECTIVE. To hire a large oceanographic vessel for a science cruise can cost $50,000 per DAY. NOT for the WHOLE CRUISE. NOT for a MONTH or a WEEK. $50,000 PER DAY. To put that in perspective: IMCS hired a vessel for a cruise that lasted about 2 months in Antarctica this past winter. Do the math. Gliders are WAY cheaper.In addition, even though vessels are hired for long periods of time, they don't gather much data compared to a glider. A vessel has to get to a station, prepare the sensors, lower the sensors, get one reading (called a "profile"), raise the sensors, wait for other science teams to complete their tasks, and then haul to the next station. And so on. Not only does this take a lot of time, but The water is only sampled at one point ever x-number of miles. Which can sometimes be tens or hundreds of miles in between. That's a lot of space that's not being sampled that we have to make "guesses" about. And that's not the best way to try to understand our oceans, or anything at that. 

Gliders are not only much more efficient in many ways, but are literally changing the type of data we can get about our oceans. Gliders can sample 24/7 along their track (or "transect"), which provides HIGH-DEFINITION, HIGH-DENSITY DATA. It's filling in all the gaps that previous technologies, such as vessels and moorings, couldn't achieve before. That means no more guessing. Just hard evidence. It's literally a miracle for ocean science.

Anyway - we digress. Where were we?...talking about the Slocum vs Seagliders. So now that you have a better idea as to the importance of gliders to ocean science: as you can see, while they both operate under the same principle of a buoyancy engine, they both look quite different. And they are. While some of their internal components are very similar, others a very different. However, they can both carry essentially the same science sensors and both have the some functional goal in mind: GET OCEANOGRAPHIC DATA.

So when it comes to gathering new data, the sensors are the same, and one could effectively interchange the vehicle (glider) upon which the sensors are carried on. But as aforementioned, the variances in the two gliders are enough for one to be preferable over the other to different users and groups.

Luckily, we don't even have to choose here at the Oceans Institute of the University of Western Australia! They operate BOTH Slocums AND Seagliders here! Which is awesome for us, because we can continue working with Slocums as we have been at Rutgers, and along the way see the variances in how UWA operates their Slocums, as well as learn how to tech and operate Seagliders!

Last week, we refurbished and prepped a Slocum, U209, for a deployment off the coast of Mindarie, Australia, about 45 minutes north of UWA/Perth. We headed out with Dennis (UWA's head glider technician...see picture below!) before sunrise on a local dive boat with a very friendly captain! Remember when we said we'd be sure to take some photos during the deployment? Well we did, but not as many as we had hoped to. To put it gently, the sea was rather restless that day 😉 There was about a 3-5 foot swell and LOTS of wind chop, so it didn't make for the best picture-taking day. I (Shannon) quickly became best friends with the bench with seasickness, and after a while of testing U209 staring at the computer screen, the wind chop got to me (Dave) a bit too and had to take my eyes off the computer for a little while too. But it's okay - it's all in the name of ocean science! However, despite the less-than-stellar conditions, the deployment was successful! And that's one of the reasons it's much better to have a glider out sampling rather than a human on a boat: humans get seasick, gliders/robots don't! Also, with seas much worse than what we went out in, we wouldn't be able to go out to sample the ocean. The safety of the scientists is paramount. However, gliders can stay out in the harshest of conditions, such as hurricanes. And these harsh conditions tend to be times that humans have never sampled before due to safety reasons - this, again, means NEW DATA.

There were a couple hiccups with U209, but that's part of game. One of which, the science computer went down while a storm hit, so we unfortunately didn't get data during that premium time. Also, the gilder wasn't flying as well as it should have been, so Dennis rendezvoused with U209 over the weekend to add a little more weight to the glider to allow it to fly better, and it worked well. A difference as little as 5 grams can make a HUGE difference in the way the 120-lbs (55,000 grams) glider flies. There's a LOT of science, physics, and math that goes into the technical and preparations of getting a glider ready for a deployment.Now that the Slocum U209 is out on its mission, we've been prepping 5 different Seagliders for deployments in all different areas of Australia! Two of those will be the gliders that we specifically use to gather oceanographic data for our research. As of now, it's looking like those two will be SG520 and SG516. But that may change as we continue the refurbishment and preparation. 

We've mostly been working technically with the Seagliders so far, so that once we get into the operation and piloting we'll have a better idea of the internal workings of the Seagliders and know exactly what we are controlling. As you can imagine, technically working with robotics' internal components is difficult and time consuming. Our experience working with Slocums is helping a lot with diminishing the learning curve with Seagliders, but of course it's quite different.

Starting this week, we'll begin getting much heavier into the operation and piloting of Seagliders. Learning how to operate, pilot, and communicate with gliders is literally like learning another language. And that applies for each different type of glider (Slocums vs Seagliders)!The surf hasn't been too great the past week or so, but a better swell is starting now! I'm (Dave) excited to get some Aussie waves! 

We went to Fremantle ("Freo" for short) last weekend, which is a small historic port town just south of Perth. It was a cool little town! We got to take a tour inside an Australian military submarine!

Other than seeing Fremantle and going to the beach, we haven't had too much time to venture out much since we've been so busy in the glider lab! But we have some fun things planned, including a hike or two (called "bushwalks" here!), a couple trips to Rottnest Island ("Rotto" for short) about 10 miles off the coast of Cottesloe Beach (where we're living), and a couple other things too! And don't forget we're spending a week in Cairns at the end of our trip on the east coast of Australia to scuba dive the Great Barrier Reef! :)!

That's all for now. Within the next couple posts, I'll get into more detail about our research project and exactly what we're going to studying about the Indian Ocean! Thanks for reading everyone! G'day mates! 🙂

Here's a couple more pictures!
-Dave & Shannon


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