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:
Downloading data from the MicroCats on the WHOTS-13 buoy’s mooring line. Back on land, the instruments will be given a more thorough cleaning, re-calibrated, and re-used next year on the WHOTS-15 buoy.Packing gear into the shipping container returning to Woods Hole, Massachusetts, at the end of the WHOTS-14 buoy deployment.
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.
Members of the science team and crew of the Hi’ialakai. Photo courtesy of Kelsey Maloney, University of Hawaii.
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.
Personal Log:
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.
Enjoying yet another gorgeous Hawaiian sunset at sea. Photo courtesy of Kelsey Maloney, University of Hawaii.
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.
The WHOTS-13 buoy after a year at sea. These three red-footed boobies will lose their perch soon!
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.
Diagram of the WHOTS-13 mooring. Image courtesy of the University of Hawaii.
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!
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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.
Personal Log:
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!”
Did You Know?
A tangled mess of anything can be called a wuzzle. For example: “I don’t know how my headphones got into such a wuzzle.” The mess of glass balls on the deck is most definitely a wuzzle.
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.
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”.
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.
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.
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:
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.
Weather Data from Bridge
Visibility: 10 miles to less than 25 miles
Wind direction: 065°
Wind speed: 06 knots
Sea wave height: small
Swell wave height: 4-6 feet
Sea level pressure: 1014.5 millibars
Cloud cover: 3, type: stratocumulus and cumulus
Buoy Technician, Sean Whelan, contacting the Acoustic Releases on WHOTS-2.
Science and Technology Log
Today was very busy because it was the day that WHOTS-2 mooring, which has been sitting out in the ocean for almost a year, was recovered. At around 6:30 a.m., Sean Whelan, the buoy technician, tried to contact the Acoustic Release. (The Acoustic Release is the device that attaches the mooring to the anchor. When it receives the appropriate signal, it disengages from the anchor, freeing the mooring for recovery. There are actually two releases on WHOTS2.) He does this by sending a sound wave at 12 KHz down through the ocean via a transmitter, and when the release “hears” the signal, it returns a frequency at 11 KHz. The attempt failed, so the ship moved closer to the anchor site and the test was repeated. This time it was successful. Based on the amount of time it takes the acoustic signal to return, the transmitter calculates a “slant range” which is the distance from the ship to the anchor. Because the ship is not directly over the anchor, this slant range creates the hypotenuse of a right triangle. Another side of the triangle is the depth of the ocean directly below the ship. Once these two distances are known, the horizontal position of the ship from the anchor can easily be calculated using the Pythagorean theorem.
Recovery of WHOTS-2 buoy aboard the R/V REVELLE.
After breakfast, the buoy recovery began. A small boat was lowered from the ship and driven over to the buoy, as the ship was steamed right near the buoy. A signal was sent down to activate the Acoustic Releases. Ropes were attached from the buoy through a pulley across the A-frame, located on the stern of the ship, to a large winch. With Jeff Lord leading the maneuvering of the 3750-pound buoy, it was disengaged from the mooring and placed safely on deck. This was a bit of a tense moment, but Jeff did a wonderful job of remaining calm and directing each person involved to maneuver their equipment to effectively place the buoy. Once the buoy was recovered and moved to the side of the deck, each instrument on the mooring was recovered. The first to appear was a VMCM, (Vector Measuring Current Meter) located just 10 meters below the buoy.
Jeff Lord, engineering technician, directing the recovery of a Vector Measuring Current Meter (VMCM).
Then two microCATs were pulled up, located 15 and 25 meters below the buoy, followed by a second VMCM. This was followed by a series of eleven microCATs located five or ten meters apart, an RDI ADCP (Acoustic Doppler Current Profiler), and two more microCATs. As each instrument was recovered, the time it was removed from the water was recorded and its serial number was checked against the mooring deployment log. Each instrument was photographed, cleaned off and sent to Jeff Snyder, an electronic technician, for data upload. Each of these instruments has been collecting and storing data at the rate of approximately a reading per minute for a year (this value varies depending on the instrument) and this data now needs to be collected. Jeff placed the instruments in a saltwater bath to simulate the ocean environment and connected each instrument to a computer by way of a USB serial adaptor port. The data from each instrument took approximately three hours to upload. Tomorrow, these instruments will be returned to the ocean alongside a CTD in order to compare their current data collection with that of a calibrated instrument.
Once all of the instruments were recovered, over 4000 feet of wire, nylon rope, and polypropylene rope were drawn up using a winch and a capstan. Polypropylene rope is used near the end of the mooring because it floats to the surface. The last portion of the mooring recovered was the floatation. This consisted of eighty glass balls chained together and individually encased in plastic. The glass balls, filled with air, float the end of the mooring to the surface when the Acoustic Releases disengage from the anchor. It takes them about 40 minutes to reach the surface. Recovering the glass balls was tricky because they are heavy and entangled in one another. Once on deck they were separated and placed in large metal bins. After dinner, a power washer was used to clean the buoy (it is a favorite resting place for seagulls and barnacles) and the cages encasing some of the instruments. The deck was cleaned and organized to prepare for tomorrow.
Recovery of mooring floatation on WHOTS-2, consisting of 80 glass balls encased in plastic.
Personal Log
The theme that keeps going through my mind during this trip and today especially, is how much of a cooperative effort this research requires. It begins with the coordination between Dr. Weller and Dr. Lukas to simultaneously collect atmospheric data using the buoy and subsurface data with the mooring instruments. In addition, Dr. Frank Bradley, an Honorary Fellow at the CSIRO Land and Water in Australia, is on the cruise working to create a manual set of data points for relative humidity using an Assman psychrometer to further check the relative humidity data produced on the buoy. Within the science teams, coordination has to occur at all stages, from the collection of data to its analysis. This was very evident in physical form today with numerous people on deck throughout the day working to retrieve the mooring, fix machinery as it broke down (the winch stopped twice), and clean the instruments. In the labs, others were working to upload data and configure computer programs to coordinate all of the data. In addition to all of this is the quiet presence of the ship’s crew who are going about their duties to be sure that the ship is running smoothly. Several of the crew did take a break today just after the instruments were collected in order to put out fishing lines! They caught numerous tuna and beautiful Mahi Mahi that the cook deliciously prepared for dinner.
Dr. Lukas, aboard the REVELLE collecting water samples from the CTD.
Dr. Roger B. Lukas Professor of Oceanography Dept. of Oceanography and Joint Institute for Marine and Atmospheric Research University of Hawaii at Manoa.
After taking a CTD sample earlier this afternoon, I spoke with Dr. Lukas, the research scientist on this cruise who is leading the recovery and replacement of the mooring components below the WHOTS-3 buoy. The following is a summary of our discussion.
Dr. Lukas encouraged to me to communicate to my students how imperative it is to set up means of continually confirming the accuracy of scientific data. The data from the mooring, for example, is compared with six or seven different profiles in order to verify the accuracy of its data and to determine when an abnormal reading has occurred (i.e. a sensor breaks or fishing lines are caught in an instrument).
Organisms both in the sample and in the surrounding water can shift the conductivity calibration in a CTD (Conductivity Temperature Depth) instrument. Therefore, the calibration of these instruments must be constantly checked and monitored. Throughout the day today at two-hour intervals, Dr. Lukas has been sending down CTD’s that provide a continuous profile of the salinity and temperature of the ocean from the surface to the maximum depth of the cast. There are sampling bottles on the rosette of the CTD that close at a depth of 10 and 200 meters. The water from these samples is brought to the surface and is used to calibrate the conductivity of the CTD. The conductivity readings (which are used to determine salinity measurements) are compared to readings taken from the sampled water via an analytical instrument called an Autosal. The Autosal is located in a lab on the ship near the main science lab. This instrument is contained in a water bath for stabilization and is kept in a temperature-controlled room. Any atmospheric pressure variations that might occur during the Autosal conductivity tests do not have enough of an effect on the conductivity determinations to create inaccuracies in salinity readings. The Autosal itself is calibrated against standard seawater which is quite expensive ($55 for a small vial) but whose salinity is known to the nearest part per million (ppm).
Salinity, or the number of grams of dissolved salts in a kg of seawater, is detected in one part per million (ppm) and is not taken as a direct measurement. Instead, both the temperature of the sample and its conductivity are measured. This is because the conductivity of seawater is affected by three variables: temperature, pressure, and salinity. Temperature affects conductivity ten times more than does salinity. Basically this means that temperature measurements must be extremely accurate in order to obtain precise salinity measurements. If a temperature reading were to be off by 1°C this would produce an error in the salinity determination by a factor of ten. This would render the salinity measurement entirely useless. Salinity measurements are related to a scale known as the Practical Salinity Scale where, for example, a reading of 35 units would be equivalent to the conductivity of 35 grams of salt in 1 kg of water. The scale is practical because the ratio of ionic chemical compounds in the ocean remains relatively constant.
Ultimately, the salinity readings produced by the instruments contained in the MicroCATs in the mooring are being compared to numerous measurements taken off of the ship via the CTD’s profiles. The CTD’s readings are being calibrated against water samples taken by closing bottles on the CTD frame at different depths, which are then measured in the Autosal, which is, in turn, calibrated against standard seawater samples. The multiple checks on the temperature measurements taken at sea are not a stringent as those of the salinity readings because the temperature instruments do not have nearly the same rate of calibration drift. Unless they are broken, they will only drift approximately one millidegree per year.
There are different types of oceanographers who study various parameters of the ocean. Dr. Lukas is a physical oceanographer as opposed to one who studies the biological or chemical aspects of the ocean. Physical oceanographers study such factors as current, waves, wind, heat content, temperature, and salinity. However, there is overlap amongst the different areas of science. A chemical determination, such as salinity, can actually be quite pertinent to the physical study of the ocean. Alterations in salinity correlate with changes in density. Variations in density gradients across the ocean cause flow or ocean currents. Other factors that affect the ocean currents include the depth of the water; wind, which drags water along; and the rotational motion of the earth. For example, if a current is moving northward, the rotation of the earth causes an apparent force to affect the water thus drawing it eastward and changing the direction of the current. Additional smaller factors that affect the current include turbulence in both the air and the sea. Turbulence is chaotic eddying motions that cause mixing amongst masses of water at different temperatures and salinities.
Dr. Lukas has a Bachelor’s degree in Mathematics, and a Master’s and PhD in oceanography. The work that he has done in earning his PhD gives him the ability to lead a research project, such as the Hawaii Ocean Time-series (www.soest.hawaii.edu/HOT_WOCE). However, Dr. Lukas noted that one does not need a PhD to be a vital part of a research team. We have people working as part of the science team on this cruise who are at the Master’s, Bachelor’s and Associate’s degree levels.
When asked about what he likes about his work, Dr. Lukas told me that he enjoys several aspects of his job. He enjoys going to sea and the fact that his work leads him to discover new things. He also values the freedom that his occupation affords him. If he is successful in obtaining funding for a proposal, he has the freedom to carry out a project of his own design. His work has taken him to a variety of places including Papua New Guinea, the Philippines and the Bay of Bengal!
It became very evident in talking with Dr. Lukas that he is devoted to this work that he so enjoys. He puts many hours into his profession. As he stated, he and Dr. Weller have continual “time and a half” jobs. His occupation involves many different aspects including being at sea, gathering data and preparing for such science cruises. He spends large chunks of time working with his research group of eight members. This work involves managing and training the members of the group as well as dealing with various personnel issues. Approximately 20% of his time is spent teaching at the graduate level. This is a smaller percentage than many of his colleagues. Dr. Lukas spends time developing projects and proposals and a significant amount of time completing the science for those that are funded. This science includes analyzing data, writing papers, attending meetings, etc. Finally, another large aspect of his job is of a more global, community nature. Like many of his colleagues, he reviews the work of other scientists. He is a member of various committees including those that make recommendations to funding agencies. He has numerous meetings each year, some of which require extensive travel. He travels to Washington D.C. several times a year, and has worked to raise awareness in congress concerning global issues relating to the ocean and our environment.
Finally, I asked Dr. Lukas if he had any advice for students interested in oceanography. He replied that, “There is no such thing as too much math or science!” One of his team members was nearby and commented that although math might seem boring in high school it becomes so important later on. Dr. Lukas confirmed that it is a tool that allows scientists to accomplish a lot. This is clearly evidenced by the work that he is able to complete.
Weather Data from Bridge
Visibility: 10 miles to < 25 miles
Wind direction: 080°
Wind speed: 12 knots
Sea wave height: small
Swell wave height: 2-4 feet
Sea level pressure: 1016 millibars
Cloud cover: 5
Cloud type: cumulus, stratocumulus
WHOTS –3 buoy during transfer from 2nd to 1st deck
The Cruise Mission
The overall mission of this cruise is to replace a mooring anchored north of the Hawaiian island of Oahu. It’s called the WHOTS buoy: The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries (HOT) Site (WHOTS). The mooring consists of a buoy that contains numerous meteorological sensors that collect data on relative humidity, barometric pressure, wind speed and direction, precipitation, short and long wave solar radiation, and sea surface temperature. The buoy serves as a weather station at sea, one of few such stations in the world.
There are two of each type of sensor on the WHOTS-3 buoy to ensure that data collection will continue should a sensor break down. The buoy is equipped with a GPS unit. The buoy also serves as a platform for observing the ocean. Hanging below the buoy are four different types of instruments. These include SeaCATs, MicroCATs, an ADCP and NGVM. The SeaCATs and MicroCATs take salinity and temperature measurements. The MicroCATs, in addition to salinity and temperature, also take depth measurements. There are several of each instrument attached to the mooring and they are located approximately 5 meters apart down to a depth of 155 meters. (The WHOTS-2 mooring only contains MicroCATs). The ADCP or Acoustic Doppler Current Profiler is an instrument that allows the scientists to measure the velocity of the current at a set of specific depths. The NGVM is a New Generation Vector Measuring device that measures the velocity of the current at fixed points using propeller sensors located at 90° to one another. Finally, two Acoustic Release Devices are attached to the anchor that is holding the mooring in place.
SeaCATs being prepared for mooring.
These instruments allow the scientists to determine the location of the anchor and will also mechanically release the mooring from the anchor when sent a specific acoustic signal. (More about how these work in a later log). The WHOTS-2 mooring has been sitting in the ocean for a year collecting data. It is powered by 4000 D-cell batteries and is capable of running off of them for about 16 months. I asked Jason Smith, the lead instrument calibration technician, why solar panels weren’t used on the buoy and he told me that they are susceptible to being shot at or stolen. Evidently anything that looks valuable in the middle of the ocean is vulnerable to theft!
Personal and Science Log
R/V REVELLE’s resident technician, Cambria Colt, operating the crane used to move the WHOTS-3 buoy to the main deck of the ship.
After arriving in Hawaii on the afternoon of Monday, June 19th, it feels good to be at sea on a moving vessel. I spent the remainder of Monday meeting the science crew from WHOI (Woods Hole Oceanographic Institution) led by the Chief Scientist, Dr. Robert Weller, having a nice dinner and falling asleep after a long day of travel.
Tuesday brought my first view of the REVELLE, a working science vessel owned by the SCRIPPS Institution of Oceanography in La Jolla, California. Go here for diagrams, pictures and statistics describing this ship. The ship has two platforms below the main deck and three decks above, not including the bridge. The main deck contains heavy equipment consisting of several winches, a crane, an electric winding cart and other machinery designed to move heavy objects. All of this equipment operation is run or overseen by Cambria Colt, the resident technician, who knows the ship like the back of her hand. It is her primary job to act as a liaison between the ships’ crew and the scientists, making sure that the needs of the science team are met. We were at the ship by 7:30 a.m. and the team started working, preparing for the cruise.
Many of the team members had already been here for a week unloading and working with the instruments. The team works well together – everyone keeps busy and seems to know what to do without a lot of discussion. I helped Jason to string up two GPS units on an upper deck of the stern of the ship as well as an antenna.
GPS units set up by science team on stern of R/V REVELLE.
The antenna is used to transmit all of the data from the mooring and from the ship to a satellite, which then directs it to WHOI. I also recorded measurements as Sean Whelan, the buoy technician, measured the distances from the top of the buoy to all of the instruments located on the buoy. He also wrapped bird wire repellant along the top of the tower of the buoy in an attempt to keep birds from landing on the instruments. The bird wire is spiky wire that jets out in various directions and can be quite treacherous to work with! Along the deck, Jeff Lord, an engineering technician, and Scott Burman, an undergraduate volunteer, worked on bolting down numerous winches to the deck that will be used to pull the buoy out of the water. Several winches are used on all sides to maintain maximum control over whatever is being maneuvered into or out of the water.
I also met the captain of the ship, Tom Desjardins, in the afternoon. I had no idea he was the captain when I first saw him, he was working hard on deck with the rest of the crew, clad in a T-shirt and shorts. He is quite affable, calm, and willing to put in a hand where it is needed. In a quick discussion with him I learned that security has become much tighter on the ship since 9/11. There are always two people on watch at the entrance to the ship when it is in port making sure that everyone who enters and leaves is accounted for. We all wear badges when we are on ship when it is in port. I also asked him about potable water use on the ship. The ship can hold 12,000 gallons of water and up to 3,000 gallons more can be distilled per day. Heat from the ship’s engines is used to distill the water.
I had Wednesday free to do a bit of sightseeing and that leads me back to today. We packed our clothes onto the ship early this morning and made up our berths (beds). The staterooms (bedrooms) are larger than I had expected. I have my own room and share a head (bathroom) with Terry Smith, another member of the team. Terry is also an undergraduate who won the NOAA Hollings Scholarship to participate on this cruise. Currently working towards a second career, Terry was a chef for 20 years before making the plunge to study science. She is working towards a degree in geo-oceanography. During the day I was able to get a computer set up and mostly watched and asked a few questions as more work was being done. The ship left port at 4:00 p.m. After taking a few pictures and watching the beauty of the coast slip away, I went back inside to attend a meeting led by Cambria and Dr. Weller.
Life Aboard Ship
Cambria talked about safety and reviewed some basics about living on the ship. We wear closed toed shoes at all times (except in our rooms), preferably steel-toed. When we are working on deck during the scientific operations we will wear hard hats and safety vests. Tomorrow there will be a safety drill at some point to be sure we all know where to “muster” and how to proceed should a fire or other problem occur on the ship. We separate our trash here – anything plastic and non-biodegradable has a separate bin. All of the paper and food waste, etc, has its own bin and is eventually tossed into the sea. Meals are at specific times during the day (and they are quite good!) but we are asked to “eat and run”, as the galley crew needs to get on with their work of cleaning up and preparing for the next meal or just getting some time off. The ship is equipped with a laundry and an exercise room. Evidently on long cruises members of the crew can be seen running laps around the main deck.
Vocabulary – Weather Data
Wind direction: Wind direction is measured in degrees, which follow the readings on a compass.
Wind speed: Measured in knots. A knot is 1 nm/hr. A nautical mile is the distance required to travel 1° longitude. It is equivalent to 1.85 km.
Sea wave height: This is the height of waves produced by the wind. This is logged in the ships log as either small or slight. The technical formula for sea wave height is .026 x (speed of wind)2.
Swell wave height: This is the height of the swells produced by distant weather patterns. Swells form a wave pattern as opposed to sea waves, which are more random. Swell wave height is measured in feet.
