Tag: NOAA Ship Hi’ialakai

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Samantha Adams: Day 6 – Testing… 1 – 2 – 3, July 29, 2017

NOAA Teacher at Sea

Samantha Adams

Aboard NOAA Ship Hi’ialakai

July 25 – August 3, 2017

Mission: Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station deployment (WHOTS-14)

Geographic Area of Cruise: Hawaii, Pacific Ocean

Date: Saturday, 29 July 2017

Weather Data from the Bridge:

Latitude & Longitude: 22o 45’N, 157o 56’W. Ship speed: 1.3 knots. Air temperature: 27.8oC. Sea temperature: 27.0oC. Humidity: 72%.Wind speed: 14 knots. Wind direction: 107 degrees. Sky cover: Few.

Science and Technology Log:

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.

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Triangulation of the WHOTS-14 buoy’s anchor location. Look at how close the ‘Anchor at Depth’ location is to the ‘Target’ location — only 177.7 meters apart! Also notice that all three circles intersect at one point, meaning that the triangulated location of the anchor is quite accurate.

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”.

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July 28, 2017, 5:58PM HAST. Preparing the rosette for a CDT cast. Notice that the grey sampling bottles are open. If you look closely, you can see clear plastic “wire” running from the top of the sampling bottles to the center of the rosette. The wires are fastened on hooks which, when triggered by the computer in the lab, flip up, releasing the wire and closing the sampling bottle.

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.

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July 28, 2017, 6:21PM HAST. On station at WHOTS-14, about halfway through a CDT cast (which typically take an hour). The cable that raises and lowers the rosette is running through the pulley in the upper right hand corner of the photo. The buoy is just visible in the distance, under the yellow arm.

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.

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July 29, 2017, 9:43AM HAST. On station at WHOTS-13. One CDT cast has already been completed; another is scheduled to begin in about 15 minutes.

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.

Personal Log:

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The Hi’ialakai’s dry lab. Everyone is wearing either a sweatshirt or a jacket… are we sure this is Hawaii?

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.

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Samantha Adams: Day 1 – Things You Never Think About, July 24, 2017

NOAA Teacher at Sea

Samantha Adams

Aboard NOAA Ship Hi’ialakai

July 25 – August 3, 2017

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.

Bird Wire

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.

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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!

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MicroCats covered in black electrical tape. Notice the bracket on the top of each instrument — they are custom-made, out of copper, to make the cleaning process that much easier when the buoy is retrieved next summer.
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Instruments on the bottom of the buoy. Once deployed, these instruments will be approximately three feet under water, which is why so much copper is used.

Personal Log:

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“You’re lucky you weren’t here when we had to load for three months!”

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!

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Samantha Adams: A Brief Introduction to… July 21, 2017

NOAA Teacher at Sea

Samantha Adams

Aboard NOAA Ship Hi’ialakai

July 25 – August 3, 2017

Mission: Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Time-series Station deployment (WHOTS-14)

Geographic Area of Cruise: Hawaii, Pacific Ocean

Date: 21 July 2017

Weather Data from the “Bridge” (New York City, NY):

Latitude & Longitude: 40.78°N, 73.97°W. Air temperature: 90°F. Wind direction: Variable. Wind speed: 7 mph. Sky Cover: Broken.

… the Science:

Aerial view of the Hi'ialakai
The NOAA ship Hi’ialakai. Photo courtesy of NOAA.

In just a few short days (huzzah!) I’ll have the privilege of sailing aboard NOAA ship Hi’ialakai on the Woods Hole Oceanographic Institution’s fourteenth Hawaii Ocean Time-series station deployment. Although I’ve not yet seen the ship or met the scientists I’ll be learning from and working with (I haven’t even left the mainland US!), I’ve been eagerly doing research to catch up on some of the basics.

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The location of the ALOHA measurement site. Photo courtesy of the University of Hawai’i.

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.

 

Diagram of Pacific Ocean circulations.
Diagram of the gyres (circulations) in the North Pacific Ocean. The green circles labeled “WGP” and “EGP” show the locations of the Western and Eastern Garbage Patches. Image courtesy of NOAA’s Pacific Islands Fisheries Science Center.
WHOTS-14 mooring diagram.
Diagram of the WHOTS station. Notice how many instruments are on the mooring line, below the surface! Photo courtesy of the University of Hawai’i.

 

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 as the 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. 

Students making weather measurements.
PAIHS Monroe students measuring water vapor and aerosols in the atmosphere, November 2016. Photo by SJ Adams.

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!

Scientific poster of atmospheric water vapor measurements.
PAIHS Monroe students studied a method of measuring water vapor in the air with an infrared thermometer as part of NASA GLOBE’s Air Quality Student Research Campaign.

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”.”