Mission: Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station deployment (WHOTS-14)
Geographic Area of Cruise: Hawaii, Pacific Ocean
Date: Thursday, 10 August 2017
Weather Data from the “Bridge”:
Latitude & Longitude:21.3245#oN,157.9251oW. Air temperature: 86oF. Humidity: 48%.Wind speed: 14 knots. Wind direction: 45 degrees. Sky cover: Scattered.
Science and Technology Log:
The data has been downloaded. The instruments have been cleaned and removed from the buoy. The lines and winches and capstans have been removed from the Hi’ialakai‘s deck. It’s all been packed away into a a shipping container, headed back to the East Coast. Next summer, it will all be shipped to Hawaii again, to head out to Station ALOHA for another year at sea, as part of the WHOTS-15 buoy deployment.
As I sit in the gate area at the Honolulu International Airport, waiting for my flight back to New York City, I’m thinking about everything I learned in my time aboard the Hi’ialakai. I’m thinking about the best way to convey it all to my students — because I love using data in my classroom. One of my favorite things to do, when I am introducing a topic, is to give them a data set — either raw numbers, graphs, or other visualizations — and have them draw some preliminary conclusions. What is the data doing? Are there trends that you notice? Does anything stand out to you? Look weird? Because I teach Earth Science, there is a wealth of publicly available data, from the USGS, from NASA, from NOAA. For just about anything I choose to teach, from the atmospheres of exoplanets to mass extinction events, a quick Google search almost always yields useful, peer-reviewed, scientific data. However, until I had the opportunity to sail aboard the Hi’ialakai and observe the deployment of the WHOTS-14 buoy and the retrieval of the WHOTS-13 buoy, I never quite appreciated just how difficult obtaining all the data I use could be.
Despite my best efforts, I think my students still believe that science is a solitary pursuit — something done by people in white coats in a lab somewhere. I hope that my experiences aboard the Hi’ialakai will help me paint a more realistic picture of what science is all about for my students. It’s a highly collaborative profession that needs people with all sorts of skills; not only science, but computer programming, mathematics, technology, logistics, resourcefulness and patience. I also hope be able to impress upon my students just how difficult doing good science can be. I know that I will certainly never look at the data sets I download with just a few clicks of my mouse the same way again.
I would like to take this opportunity to say mahalo nui loa (thank you very much) to everyone aboard the Hi’ialakai for the WHOTS-14 cruise — for answering all my questions, even the ones I didn’t think to ask; for sharing data, seasickness medication, hardhats, and the occasional power tool; for the fabulous meals (and the best chocolate chip cookies ever!); for the impromptu education about monk seals and the philosophical discussion on fidget spinners.
It’s been a truly unforgettable experience, and I can’t wait to dig into the hard-won data from the WHOTS buoys and share it all with my students.
Did You Know?
Dry land can feel like it’s moving, too! After spending an extended amount of time at sea, your body seems to expect the ground to be rolling underneath your feet, just like the deck of the ship… but nope! Just you! One slang term for this is “dock rock” — and it’s more than a little strange.
It’s deja vu all over again! The WHOTS-14 buoy is stable and transmitting data, and all the in situ measurements necessary to verify the accuracy of that data have been taken. Now it’s time to go get the WHOTS-13 buoy, and bring it home.
The process of retrieving the WHOTS-13 buoy is essentially the same as deploying the WHOTS-14 buoy — except in reverse, and a lot more slimy. Take a look at the diagram of the WHOTS-13 buoy (to the left), and you’ll notice that it looks almost identical to the WHOTS-14 buoy. Aside from a few minor changes from year to year, the configuration of the buoys remains essentially the same… so the three and a half miles of stuff that went into the ocean on Thursday? The same amount has all got to come back up.
At 6:38AM HAST, a signal was sent from the ship to the acoustic releases on the WHOTS-13 buoy’s anchor. After a year under three miles of water, the mooring line is on its way back to the surface!
From the time the signal was sent to the acoustic releases on the anchor to last instrument coming back on board, recovering the WHOTS-13 buoy took 9 hours and 53 minutes.
Now that I have witnessed (and participated in, however briefly) both a buoy deployment and retrieval, one of the things that impressed me the most was how well coordinated everything was, and how smoothly everything went. Both deployment and retrieval were reviewed multiple times, from short overviews at daily briefings (an afternoon meeting involving the ship’s officers, crew and the science team) to extensive hour long “walk throughs” the day before the main event. Consequently, everyone knew exactly what they were supposed to be doing, and where and when they were supposed to be doing it — which lead to minimal discussion, confusion and (I assume) stress. Each operation ran like a well choreographed dance; even when something unexpected happened (like the glass ball exploding on deck during deployment of the WHOTS-14 buoy), since everybody knew what the next step was supposed to be, there was always space to pause and work through the problem. Communication is most definitely key!
The other thing that really made an impression was how much emphasis was placed on taking breaks and drinking enough water. It was hot, humid and sunny during both deployment and recovery, and since Hi’ialakai had to be pointed directly into the wind during the operations, there was virtually no wind on the working deck at all. I’ve always thought as the ocean as a place you go to cool off, but, at least for these few days, it’s been anything but! With apologies to Coleridge: “Water, water, everywhere, nor any place to swim!”
The most difficult part of Thursday’s buoy deployment was making sure the anchor was dropped on target. Throughout the day, shifting winds and currents kept pushing the ship away from the anchor’s target location. There was constant communication between the ship’s crew and the science team, correcting for this, but while everyone thought we were close when the anchor was dropped, nobody knew for sure until the anchor’s actual location had been surveyed.
To survey the anchor site, the ship “pinged” (sent a signal to) the acoustic releases on the buoy’s mooring line from three separate locations around the area where the anchor was dropped. This determines the distance from the ship to the anchor — or, more accurately, the distance from the ship to the acoustic releases. When all three distances are plotted (see the map above), the exact location of the buoy’s anchor can be determined. Success! The buoy’s anchor is 177.7 meters away from the target location — closer to the intended target than any other WHOTS deployment has gotten.
After deployment on Thursday, and all day Friday, the Hi’ialakai stayed “on station” about a quarter of a nautical mile downwind of the WHOTS-14 buoy, in order to verify that the instruments on the buoy were making accurate measurements. Because both meteorological and oceanographic measurements are being made, the buoy’s data must be verified by two different methods.
Weather data from the buoy (air temperature, relative humidity, wind speed, etc.) is verified using measurements from the Hi’ialakai’s own weather station and a separate set of instruments from NOAA’s Environmental Sciences Research Laboratory. This process is relatively simple, only requiring a few quick mouse clicks (to download the data), a flashdrive (to transfer the data), and a “please” and “thank you”.
Salinity, temperature and depth measurements (from the MicroCats on the mooring line), on the other hand, are much more difficult to verify. In order to get the necessary “in situ” oceanographic data (from measurements made close to the buoy), the water must be sampled directly. This is done buy doing something called a CTD cast — in this case, a specific type called a yo-yo.
The contraption in the picture to the left is called a rosette. It consists of a PCV pipe frame, several grey sampling bottles around the outside of the frame, and multiple sets of instruments in the center (one primary and one backup) for each measurement being made.
The rosette is hooked to a stainless steel cable, hoisted over the side of the ship, and lowered into the water. Cable is cast (run out) until the rosette reaches a certain depth — which can be anything, really, depending on what measurements need to be made. For most of the verification measurements, this depth has been 250 meters. Then, the rosette is hauled up to the surface. And lowered back down. And raised up to the surface. And lowered back down. It’s easy to see why it’s called a yo-yo! (CDT casts that go deeper — thousands of meters instead of hundreds — only go down and up once.)
For the verification process, the rosette is raised and lowered five times, with the instruments continuously measuring temperature, salinity and depth. On the final trip back to the surface, the sampling bottles are closed remotely, one at a time, at specific depths, by a computer in the ship’s lab. (The sampling depths are determined during the cast, by identifying points of interest in the data. Typically, water is sampled at the lowest point of the cast and five meters below the surface, as well as where the salinity and oxygen content of the water is at its lowest.) Then, the rosette is hauled back on board, and water from the sampling bottles is emptied into smaller glass bottles, to be taken back to shore and more closely analyzed.
On this research cruise, the yo-yos are being done by scientists and student researchers from the University of Hawaii, who routinely work at the ALOHA site (where the WHOTS buoys are anchored). The yoyos are done at regular intervals throughout the day, with the first cast beginning at about 6AM HAST and the final one wrapping up at about midnight.
After the final yo-yo was complete at the WHOTS-14 buoy early Saturday morning, the Hi’ialakai traveled to the WHOTS-13 buoy. Today and tomorrow (Sunday), more in situ meteorological and oceanographic verification measurements will be made at the WHOTS-13 site. All of this — the meteorological measurements, the yo-yos, the days rocking back and forth on the ocean swell — must happen in order to make sure that the data being recorded is consistent from one buoy to the next. If this is the case, then it’s a good bet that any trends or changes in the data are real — caused by the environmental conditions — rather than differences in the instruments themselves.
Most of the science team’s time is divided between the Hi’ialakai’s deck and the labs (there are two; one wet, and one dry).The wet lab contains stainless steel sinks, countertops, and an industrial freezer; on research cruises that focus on marine biology, samples can be stored there. Since the only samples being collected on this cruise are water, which don’t need to be frozen, the freezer was turned off before we left port, and turned into additional storage space.The dry lab (shown in the picture above) is essentially open office space, in use nearly 24 hours a day. The labs, like most living areas on the ship, are quite well air conditioned. It may be hot and humid outside, but inside, hoodies and hot coffee are both at a premium!
Did You Know?
The acronym “CTD” stands for conductivity, temperature and depth. But the MicroCats on the buoy mooring lines and the CTD casts are supposed to measure salinity, temperature and depth… so where does conductivity come in? It turns out that the salinity of the water can’t be measured directly — but conductivity of the water can.
When salt is dissolved into water, it breaks into ions, which have positive and negative charges. In order to determine salinity, an instrument measuring conductivity will pass a small electrical current between two electrodes (conductors), and the voltage on either side of the electrodes is measured. Ions facilitate the flow of the electrical current through the water. Therefore conductivity, with the temperature of the water taken into account, can be used to determine the salinity.
It’s deployment day! After months of preparation and days of practice, this buoy is finally going in the water!
The sheer volume of stuff that’s involved is mind boggling. There’s the buoy itself, which is nearly 3 meters (approximately 9 feet) tall; one meter of that sits below the surface. There’s 16 MicroCats (which are instruments measuring temperature, salinity and depth of the water) attached to over 350 meters of chain and wire. Then there’s another 1,800 meters of wire and 3,600 meters of two different types of line (rope) — heavy nylon and polypropylene. Then there’s 68 glass balls, for flotation. After that, there’s another 35 meters of chain and nylon line. Attached to that is an acoustic release, which does exactly what it sounds like it does — if it “hears” a special signal, it detaches from whatever is holding it down. In this case, that’s a 9,300 pound anchor. (The acoustic release and the glass balls make sure that all the instruments on the mooring line can be recovered.) All in all, nearly 6,000 meters — three and a half miles — of equipment and instrumentation is going over the stern of the Hi’ialakai. The length of the mooring line is actually longer (approximately one and a quarter times longer) than the ocean is deep where the buoy is being deployed. This is done so that if (or when) the buoy is pulled by strong winds or currents, there is extra “space” available to keep the buoy from getting pulled under water.
Take a look at the diagram of the WHOTS-14 buoy. It’s easy to assume that the everything goes into the water in the exact same order as is shown on the diagram — but the reality of deployment is actually very different.
First, the MicroCats that are attached to the first 30 meters of chain (6 of them) go over the side. Approximately the first five meters of chain stay on board, which is then is attached to the buoy. After that, the buoy is hooked up to the crane, and gently lifted off the deck, over the side, and into the water. Then, the remaining ten MicroCats are attached, one by one, to the 325 meters of wire and, one by one, lowered into the water. Then the additional 3,400 meters of wire and nylon line are slowly eased off the ship and into the ocean. After that, the glass balls (two-foot diameter spheres made of heavy glass and covered by bright yellow plastic “hats”) are attached and join the rest of the mooring line in the ocean. Finally, after hours of hard work, the end of the mooring line is attached to the anchor. Then, with a little help from the ship’s crane, the anchor slides off the stern of the ship, thunks into the water, and slowly starts making its way to the bottom.
4:18PM HAST: Splashdown! The anchor is dropped.
From the morning-of preparations to the anchor sliding off the Hi’ialakai’s stern, deploying the WHOTS buoy took 9 hours and 41 minutes.
Another item to file under Things You Never Think About: Velcro is awesome. Ships — all ships, even one the size of the Hi’ialakai — frequently move in unexpected, jarring ways. (If you’ve never been on a ship at sea, it’s a bit like walking through the “Fun House” at a carnival — one of the ones with the moving floors. You try to put your foot down, the floor drops a few inches underneath you, and you’re suddenly trying to walk on air.) For this reason, it’s important to keep everything as secured as possible. Rope and straps are good for tying down things that can stay in one place, but something like a laptop, which needs to be mobile? Velcro!
Did You Know?
Not all line is created equal. Aside from obvious differences in the size and color, different lines have different purposes. The heavy nylon line (which is white; see the picture in slideshow of the line being deployed) is actually able to stretch, which is another safety precaution, ensuring that the buoy will not be pulled under water. The light blue polypropylene line, called Colmega, floats. In the picture to the left, you can see a light blue line floating in the water, stretching off into the distance. It’s not floating because it’s attached to the ship — it’s floating all by itself!
Mission: Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station deployment (WHOTS-14)
Geographic Area of Cruise: Hawaii, Pacific Ocean
Date: Monday 24 July 2017
Weather Data from the Bridge:
Latitude & Longitude: 21o22’N, 157o57’ W. Ship speed: 0 knots. Air temperature: 82oF. Humidity: 74%.Wind speed: 8 knots. Wind direction: East-South-East. Sky cover: Broken.
Science and Technology Log:
One of the first things you learn to do as a teacher is to plan for things to go wrong. When you put a lesson together, you try to identify potential problem areas, and then try to figure out how you could address those problems when they do arise, or try to avoid them altogether. One of the next things that you learn is that the biggest problem is invariably going to be something you never anticipated being a problem at all. Deploying a research buoy, it turns out, works essentially the same way.
WHOTS stations are massive, self-contained buoys, designed to stay at sea for up to eighteen months, collecting data the entire time. There are redundant systems on top of redundant systems. Multiple meteorological instruments, measuring exactly the same thing, sprout from the buoy’s tower like misshapen mushrooms. If one instrument fails, there is always another — to ensure that, no matter what, the data is collected. And surrounding it all, like the spines of a porcupine, is the bird wire.
Anything that floats on the ocean winds can be a perch for birds, and the WHOTS buoys are no exception. I’ve been told that after a year at sea, the buoy is absolutely disgusting. I’ve seen some of the mess New York City pigeons can create, and I’m willing to bet that what I’m imagining cannot even come close. I’ll find out for myself later this week, when we retrieve the WHOTS buoy that was deployed last year!
Ick factor aside, birds (and their waste products) pose a real danger to the instruments on the buoy’s tower. If something is pecked or perched on or — use your imagination — otherwise damaged, the instruments may record corrupted data, or no data at all. Which is why there are redundant systems, and why Monday morning was spent making the buoy look like a porcupine. But wait! There’s more! It turns out all bird wire is not created equal. All of the spikes are made of stainless steel, but the spikes can be mounted on different things. Bird wire with a stainless steel base is more effective at repelling birds (because the spikes are closer together)… but the spikes have to be welded into the base, which magnetizes the bird wire. And if this wire is placed the instruments, it can affect their internal compasses and, in turn affect the data the bird wire is intended to protect! Bird wire with a plastic base is less effective (because the spikes are further apart), but much safer for the buoy’s instruments.
Cayenne Pepper, Copper and Things Covered in Tape
The tower of the WHOTS buoy isn’t the only thing that is absolutely disgusting after spending a year at sea. Everything that spends the year below the surface of the ocean (which will be described in a post later this week) comes back absolutely disgusting, too. And it’s not as though it can all just be thrown away. Of particular importance are the instruments attached under the buoy and about every 10 meters (down to 150 meters) along the buoy’s mooring line. All of these instruments must be returned to the manufacturer for calibration (to make sure they were working properly). But there’s a catch — they must be returned clean! Which means that everything that has been growing on them while they’ve been under water must be scrubbed, scraped or peeled off. To make the job easier, the search is always on for ways to keep things from growing on the instruments in the first place. This is called antifouling.
One antifouling method is painting. There are specialized antifouling paints available, but they can be toxic. So the paint that covers the exterior of the buoy contains cayenne pepper (!), which has proven to be as effective as specialized paint, but is much safer. Another antifouling method used on many of the instruments under the buoy involves replacing some stainless steel components with specially made copper ones, as copper also naturally impedes growth. And a third method that’s very popular is simply to cover the instruments with a layer of electrical tape, which can just be peeled off — no scrubbing or scraping involved!
Throughout the day, refrigerated trucks pulled up on the dock next to the Hi’ialakai. They were not full of delicate scientific instrumentation, but something just as vitally important to the cruise — food! The same crane that had been used to hoist instruments on board was also used to carry pallets of food from the dock to the deck of the ship. Then it was passed from hand to hand (by members of the ship’s crew, the science team, the ship’s officers, and the Teacher at Sea) all the way down to the galley’s refrigerators and freezers. The ice cream was handled with particular care — no surprise there!
Did You Know?
Woods Hole Oceanographic Institution’s acronym — WHOI — has a pronunciation! You can say it like “hooey”. Or “whoo-ey!” It means the same thing either way!
Since 2004, the WHOTS stations have been measuring the interactions between the ocean and the atmosphere, as part of a long term study on ocean circulation. The site where the WHOTS stations are deployed is called ALOHA (A Long-Term Oligotrophic Habitat Assessment), located about 100 kilometers north of Oahu, Hawaii. The ALOHA station, maintained and monitored by the University of Hawai’i since 1988, makes oceanographic measurements (like water temperature, direction and speed of ocean currents, and amounts of plankton). The objective of the project is to use the area as a case study, as it is representative of the North Pacific subtropical gyre.
WHOTS stations are moored (anchored) buoys. The buoy includes instruments floating on the surface to measure the weather (air temperature, wind speed, relative humidity, etc.), and there are also instruments along the mooring line to measure things like water temperature, currents and salinity. The instruments below the surface make measurements at the same time asthe meteorological measurements on the surface, so that air and sea interactions can be accurately studied.
Scientists from the Woods Hole Oceanographic Institution visit the ALOHA site every year, to deploy a new WHOTS station, and retrieve older ones. Check out this video of the WHOTS-13 research cruise!
… the Teacher:
The summer I turned five, my house was struck by lightning. The bolt blew out my window, scattering glass shards across my bed, blasted chunks of concrete out of the driveway below, and set the garage on fire — which was almost immediately put out by torrential rain. I have been fascinated by the atmosphere ever since. When I learned I had been chosen for the WHOTS-14 research cruise, I was ecstatic. Not only because I’d been selected to participate in such an amazing opportunity, but because I would have the chance to learn more about the oceans, and how they interact with the ocean of air above them.
I have taught science in New York City for eight years. For the past six years, I have taught twelfth grade geoscience at Pan American International High School at the James Monroe campus (PAIHS Monroe), in the Bronx. Each year, I do my best to get my students as excited about science as I am. For the past few years, that has meant dragging them outside in near-freezing temperatures to measure the local air quality. (So, maybe not the best method I could have chosen!)
(All of my students: “It’s too cold, Miss!” Samantha: “If it’s not too cold for the instruments, it’s not too cold for you!”)
These measurements were made as part of NASA GLOBE‘s Air Quality Student Research Campaign, and I was able to present their work at NASA Langley Research Center.
I hope that my experiences aboard the Hi’ialakai with the WHOTS-14 research cruise will teach me more about the ocean of air we live in, and help me develop more — warmer — ways to get my students interested in science!
Did You Know?
From NOAA’s Office of Marine and Aviation operations page: “Hi‘ialakai is a combination of Hawaiian words. Hi‘i means “to hold in one’s arms”; ala is route; and kai is the sea. Thus, NOAA named this ship to signify “embracing pathways to the sea”.”