Frank Hubacz: ADCP Deployment, May 2, 2013

NOAA Teacher at Sea
Frank Hubacz
Aboard NOAA ship Oscar Dyson
April 29 – May 10, 2013

 

Mission: Pacific Marine Environmental Laboratory Mooring Deployment and Recovery
Geographical Area of Cruise: Gulf of Alaska and the Bering Sea
Date: May 2, 2013

Weather Data from the Bridge:

Partly sunny, WindsN 5-10 knots
Air Temperature 1.3C

Relative Humidity 60%

Barometer 1008.2 mb

Surface Water Temperature 2.8C

Surface Water Salinity 31.37 PSU

Science and Technology Log

As I described previously, one of the instruments being deployed on this cruise is an Acoustic Doppler Current Profiler (ADCP), which measures speed and direction of ocean currents across an entire water column using the principle of Doppler shift (effect).  The Doppler Effect is best illustrated when you stop and listen to the whistle of an oncoming train.  When the train is traveling towards you, the whistle’s pitch is higher. When it is moving away from you, the pitch is lower. The change in pitch is proportional to the speed of the train.  The diagrams below illustrates the effect.

Doppler Effect

Doppler Effect

Another view of the Doppler Effect
Another view of the Doppler Effect

The ADCP exploits the Doppler Effect by emitting a sequence of high frequency pulses of sound (“pings”) that scatter off of moving particles in the water. Depending on whether the particles are moving toward or away from the sound source, the frequency of the return signal bounced back to the ADCP is either higher or lower. Since the particles move at the same speed as the water that carries them, the frequency shift is proportional to the speed of the water, or current.

The ADCP has 4 acoustic transducers that emit and receive acoustical pulses from 4 different directions. Current direction is computed by using trigonometric relations to convert the return signal from the 4 transducers to ‘earth’ coordinates (north-south, east-west and up-down. (http://oceanexplorer.noaa.gov/technology/tools/acoust_doppler/acoust_doppler.html).  The most common frequencies used on these units are 600 KHz, 300 KHz, and 75 KHz.  The lower the frequency the greater the distance that the wave can propagate through the ocean waters.

Determining current flow helps scientist to understand how nutrients and other chemical species are transported throughout the ocean.

Typical 4 beam ADCP sensor head. The red circles denote the 4 transducer faces.

Typical 4 beam ADCP sensor head. The red circles denote the 4 transducer faces.

Prior to sailing, ADCP mooring locations are selected by various research scientists from within NOAA.  Next, engineers develop a construction plan to secure the unit onto the ocean floor.  Once designed, the hardware needed to construct the mooring is sent to the ship that will be sailing in the selected mooring locations.  Prior to arriving at the designated location it is the responsibility of the science team to construct the mooring setup following the engineering diagram shipped with each ADCP unit. ADCP moorings can be constructed to hold a wide variety of measuring instruments depending upon the ocean parameters under study by the research scientist.

ADCP Construction Diagram

ADCP Construction Diagram

The moorings are built on the ship’s deck starting with an anchor.  The anchor weight is determined based upon known current strength in the area where the mooring will be located.  Anchors are simply scrap iron railroad train car wheels which bury themselves into the sediment and eventually rust away after use.  The first mooring unit that we assembled had an anchor composed of two train wheels with a total weight of 1,600lbs.  Although this mooring was built from the anchor up this is not always the case.  When setting very deep moorings the build is in the reverse order.

Selecting the anchor

Selecting the anchor

Anchor on the back deck

Anchor on the back deck below the gantry

Next, an acoustic release mechanism is attached to the anchor by way of heavy chains.  This mechanism allows for recovery of the ADCP unit as well as the release mechanism itself when it is time to recover the ADCP.  The units that we are deploying will remain submerged and collect data for approximately 6 months.

Acostic Release Mechanism
Acoustic Release Mechanism
Bill attaching the acoustic release mechanism

Bill attaching the acoustic release mechanism

Finally, an orange closed-cell foam and stainless steel frame containing the actual instrumentation is connected to the assembly and then craned over the back deck.  The stainless steel frame has a block of zinc attached to it which acts as a sacrificial anode.  Sacrificial anodes are highly active metals (such as zinc) that are used to prevent a less active metal surface from rusting or corroding away.  In fact, our ship has many such anodes located on its hull. Once the entire unit is in position, a pin connected to a long chord is pulled from a release mechanism and the unit is dropped to the ocean floor.  Date, time, and location for each unit are then recorded. 

Hoisting ADCP

Hoisting ADCP

ADCP unit assembly

ADCP unit assembly

Assembling mooring unit

Assembling mooring unit

Ready for launch

Ready for launch

To recover the unit, an acoustic signal (9-12 Khz) is sent to the ship from the sunken mooring unit to aid in its location.  Once located, a signal is used to activate a remote sensor which powers the release mechanism to open.  The float unit then rises to the surface bringing all of its attached instruments along with it.  The stored data within the units are then secured and eventually sent along to the research scientist requesting that specific mooring location for ocean current analysis.

Recovering a mooring with a rope lasso

Recovering a mooring with a rope lasso

Personal Log

On my first day of “work” I was able to watch the science teams deploy three different ADCP moorings as well as conduct several CTD runs.  I will discuss CTD’s in more detail in future blogs.  I was impressed by the camaraderie among all of the science team members regardless of the institution that they represented as well as with members of the deck crew.  They all work as a very cohesive and efficient group and certainly understand the importance of teamwork!

Adjusting to my new work schedule is a bit of a challenge. After my work day ended today at 1200 hours, I fell asleep around 1500 hours for about 4 hours.  After trying to fall back asleep again, but to no avail, I decided to have a “midnight” snack at 2000 hours (8pm).  I finally fell asleep for about 2 more hours before showering for my next shift.  I think I now have more empathy for students who come to my 8am chemistry class and occasionally “nap”!

A wide selection of food is always available in the ship’s galley. I have discovered that I am not the only one taking advantage of this “benefit”!  I will definitely need to reestablish an exercise routine when I return home.  We are currently heading for Unimak Pass which is a wide strait between the Bering Sea and the North Pacific Ocean southwest of Unimak Island in the Aleutian Islands of Alaska.

Did you know that since the island chain crosses longitude 180°, the Aleutian Islands contain both the westernmost and easternmost points in the United States. (172° E and 163° W)!

180 longitude

Kathy Schroeder, May 12, 2010

NOAA Teacher at Sea
Kathy Schroeder
Aboard NOAA Ship Oscar Dyson
May 5 – May 18, 2010

Mission: Fisheries Surveys
Geographical Area: Eastern Bering Sea
Date: May 12, 2010

5/12 Mooring Buoy

Launching a mooring buoy

Launching a mooring buoy

Today we launched another type of buoy. It is called a Mooring Buoy. Its height is 5 meters above the surface (pictured on left) and 72 meters below the surface, which ends with a concrete dome that weighs 4110 (pictured on right). You can see the mooring being towed by the ship to get it into the right position. It has a barometer (measures atmospheric pressure), an anemometer (measures wind speed) and a thermometer on the top. There are sensors at different depths that measure salinity, chlorophyll, temperature, pressure, and nitrates.The information is transmitted to satellite Pacific Marine Environmental Lab (NOAA) that monitors the surface and subsurface of the Bering Sea. This piece of equipment costs $250,000. There are two other moorings already in this location. One measures ocean currents the other measures acoustic plankton. On one it has an underwater rain gauge. Can you figure out what that means? Headed to the Pribilof Islands today. On the way some crew saw sea ice. I’ll be looking! I love reading everyone’s comments. Keep them coming!

Vince Rosato and Kim Pratt, March 27, 2006

NOAA Teacher at Sea
Vince Rosato & Kim Pratt
Onboard NOAA Ship Ronald H. Brown
March 9 – 28, 2006

Mission: Collect oceanographic and climate modeling data
Geographical Area: Eastern Florida
Date: March 27, 2006

Screen shot 2013-04-08 at 4.44.27 PMScience and Technology Log

Today we had a special treat; we were a part of a “Man Over board” drill! A man overboard drill is held once during a three-month period so the crew is prepared in case someone falls off the ship  into the ocean. The drill starts with a “dummy” which is made of an old Mustang (survival suit) and is named Oscar. Next, the Captain makes a call to the Bridge (where they run the ship), and three bells are sounded.  These three bells are Morse code (a code of lights or bells that spell out words) and they make the letter “O” for Oscar. Everyone responds to a “Man Over Board” to search for the missing person, or in this case the dummy.  Once the dummy was located, the ship traveled to the dummy and brought it on board by means of a large hook.  At this point, LCDR Rodriguez and Chief Scientist Dr. Molly proceeded to practice CPR (Cardio Pulmonary Resuscitation– to get the heart started and air into the lungs) on the dummy.  Finally, an all-clear signal was given and the dummy was then put away for a drill later on in the year. It was very exciting.

Water was collected from the Bermuda Triangle for Ms. Pratt’s fifth grade class.  This area is known for strange disappearances. The Bermuda Triangle is located between the island of Bermuda, Miami, Florida and San Juan, Puerto Rico.  Many people have tried to explain what happens to the ships, small boats and planes that disappear and the most reasonable explanation is that there are environmental factors (weather, sea conditions) at play or human mistakes.

Interview with Julia O’Hern 

Julia O’Hern is a graduate student in biological oceanography at Texas A & M  (Agriculture and Military) University. She comes from the Hawkeye State, Iowa.  Julia loves being outside and in the water.  She has an interest in environmental science, and this led her to the ocean. Her parents always promoted science activities.  For instance, Julia recalls her summer, hiking through the prairie, catching bugs and identifying them.  Julia had an environmental science course in her high school boarding school that taught her how to be a field scientist. Julia feels lucky that a creek ran by her home and she could collect big ugly tadpoles.  From fifth grade through college she played softball, ran track, and she swam.  Julia likes chemistry and physics and is working on a degree in biological oceanography but truly loves whales. “Marine biology,” Julia explains, “is different from oceanography,” which studies how some of the physical processes in the ocean (waves, sea floor, and water) affect where the whales live. Marine biology studies the whale itself including its life cycle, its behavior and how it is affected by people.

Ms. Pratt collecting water from the Bermuda Triangle.

Ms. Pratt collecting water from the Bermuda Triangle.

“One of the only times I was out of Iowa, my parents took me on trip off of Maine and we saw whales,” said Julia. This inspired her.  To top everything off, she shared, “The coolest thing to ever experience is to be in the water when a humpback whale is singing.  It doesn’t even matter how far away they are, you feel their music.”  Books she suggested reading are Farley Moats’s, Never Cry Wolf and Jack London’s Call for the Wild as well as anything by Jane Goodall.  Her advice to students is: “If you want to do oceanography and study marine life you have to get past math and computers, and it won’t always be fun.” But, Julia agrees it’s worth it.

Assignment: In your sea logs, write the procedure for a “Man Over Board” drill.  Label each step that happens.  For example:   #1 – Put “Oscar” into the ocean.

Personal log – Kimberly Pratt 

This has been a very exciting trip! I’ve been stretched beyond my wildest dreams.  The correspondence with my students has been meaningful and very educational.  Working with the scientists, officers, crew and my fellow teacher has taught me lessons that I’ll never forget! Thanks to all of you for this unforgettable experience.

Personal Log – Vince Rosato 

Thanks to Captain Gary Petrae for welcoming us onboard and sharing so freely resources to help kids understand life at sea. Thanks, too, to Dr. Molly for extending this experience to us through NOAA. Thanks to my principal, Debbi Knoth, and the New Haven Unified School District Superintendent, Dr. Pat Jaurequi, for enabling this trip and to Kim Pratt for inviting me along.  Thanks to the crew!  Thanks to Mrs. Riach for substituting for me.  There are so many interesting and exciting happenings on board.  Juliet was a hit and remains with Lt. Commander Priscilla Rodriguez.  As Professor Jochem Marotzke shared, life at sea sensitizes you to put yourself in another’s shoes, simply because the job isn’t done when my own shift is over.  I had the pleasure of getting quotes from many people here.  Robert Bayliss, onboard from the THOMAS JEFFERSON for this cruise, advised anyone interested in life at sea to “Be prepared to spend long times away from home.”  Being one of Carlos’ boys with Rigo, Dallas and Mick was a “bonus.” At an all-hands meeting this afternoon we shared our gifts for the crew and NOAA scientists.

Afterwards those who wished got their picture taken in groups.  Dr. Molly created a centralized computer space for sharing pictures.  I have some CD’s to work with, thanks to Dr. Shari and LCDR Rodriguez. Those kinds of sensibilities make life pleasant.  I understand my Uncle Sam better from this cruise.  I cannot leave without a special hello to my 14-year-old daughter, Alexandria Jo.  When we return, there will be extension activities, such as lesson plans, presentations to prepare and publicity pieces.  My enriched enthusiasm and understanding of ocean science will be shared with every student. I got autographs from world-class oceanographers, modern-day explorers, and stand in awe at the collaborative efforts being made to better understand the ocean and its relationship to climate.  The current issue of Mother Jones is devoted to the state of the seas. Gratitude was my beginning attitude and remains as I prepare to return to land.  What makes a fine sailor also remains: someone who knows their job and gets it done, is dependable, a friendly person to be around, and one who you can trust to watch your back. This applies as a major lesson to those in all walks of life.

Vince Rosato and Kim Pratt, March 26, 2006

NOAA Teacher at Sea
Vince Rosato & Kim Pratt
Onboard NOAA Ship Ronald H. Brown
March 9 – 28, 2006

Mission: Collect oceanographic and climate modeling data
Geographical Area: Eastern Florida
Date: March 26, 2006

Mooring team at work

Mooring team at work

Science and Technology Log

Besides deploying (launching) buoys, and doing CTD casts, the RON BROWN also has a group of scientists from the United Kingdom (which consists of the countries England, Scotland, Wales, and Northern Ireland) and a scientist from Germany who are putting moorings in the ocean.  Moorings are instruments that are sent to the bottom of the ocean and are held there with weights. They can weight up to 3000 pounds!

Also attached to the moorings are floats so that when the scientists decide to get the instruments, they send a signal to the mooring to detach from the weight and then it can float to the surface.  After that, the scientists can easily locate the floats in the ocean and then pick the instrument up.  The moorings send information to the scientists about the velocity (or speed) of the deep-water currents.  They also measure temperature, salinity, pressure and tidal heights. Each mooring costs about $200,000 each!

On the RON BROWN, three large moorings were recovered (picked up) and four more were deployed (put into the ocean).  This team has deployed moorings all across the Atlantic Ocean— from west of Morocco, near the Sahara desert region, to east of the coast of Florida (where we are now.)

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LT Liz Jones

Interview with LT Liz Jones, Field Operations Officer  

LT Liz Jones defined herself as Field Operations Officer, or FOO, as “a coordinator of scientific operations between the science party and the ship’s crew to ensure the mission is carried out and the scientific objectives are met.”  While all NOAA Corps Officers have either science or engineering backgrounds, she also had prior seagoing experience before joining the NOAA Corps in 1999. Liz graduated from the Massachusetts Maritime Academy in 1996, majoring in Marine Safety and Environmental Protection.  Maritime academies provide classrooms at sea aboard their training ships.

An interactive program called the “Voyage of the MIMI” sparked her interest in the 5th grade. It sounded similar to the current “Jason Project,” where a scientific team videotapes and teleconferences their work from interesting places in the ocean.  Liz explained to a high school guidance counselor, “I love the ocean; I want to do some kind of work with the ocean.”  Fifteen years later, she is doing just that!

NOAA Corps officers attend three months of Basic Officer Training at the US Merchant Marine Academy in Kings Point, New York. From there, they are sent to sea aboard one of NOAA’s research vessels. A typical career has one rotating two years at sea and three years on land. “I really like the idea of reinventing myself every few years,” Liz explained.  The RONALD H BROWN is her second sea assignment.  Liz worked at NOAA’s headquarters for her first land assignment  She spent one year there as an aide to Rear Admiral Evelyn J. Fields, who was the first African American female to head the NOAA Corps.

As the FOO, Liz is always planning ahead. She stays very busy working on the plan of the day for tomorrow or the logistics for the next four cruises.  The most challenging projects to coordinate are the ones where new technologies will be used for the first time.  She is thankful to the crew that can make just about anything happen.  In her spare time, Liz works out, reads a good book or just relaxes.  For interested students, The California Maritime Academy in Vallejo has the Training Ship GOLDEN BEAR, which one day could be your very own classroom at sea.

Assignment: Using a world map, locate Morocco, the Sahara Desert and the east coast of Florida. Draw moorings straight across the ocean to connect these areas.

Personal Log – Kimberly Pratt 

We finally finished our CTD casts!  The last job I learned was how to be “Sample Cop”, which means I wrote down information about each water sample that was taken.  When scientists take samples, they need to clean each bottle three times before they fill it with the sample.  This is so the sample is pure and not contaminated (dirty) from the previous sample.  We use a lot of seawater for this purpose.  Thanks for all the e-mails!

Personal Log – Vince Rosato 

I checked out the drifting buoy-tracking site and found our buoy!  I have been busy responding to your emails and writing logs.  The scientists and crew have been very helpful in helping me be accurate and sensitive in the presentation of the work being done out here. I salute my nephew, in the Navy now.  We are getting excited about coming into port in a couple more days.