Acoustic Doppler Current Profiler – NOAA Teacher at Sea Blog

May 3, 2013August 11, 2021

Frank Hubacz: Our First Day at Sea, April 29, 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: April 29, 2013

Weather Data from the Bridge:

Partly cloudy, Winds 10 – 15 knots
Air temperature: 4.0 C
Water temperature: 5.3 C
Barometric Pressure: 1014.14 mB

Science and Technology Log

The primary mission of this cruise is to deploy and recover moorings in several locations in the Gulf of Alaska and the Bering Sea. These moorings collect data for a group of scientist under the auspices of the Ecosystems & Fisheries-Oceanography Coordinated Investigations (EcoFOCI) which is a joint venture between the NOAA Pacific Marine Environmental Laboratory (PMEL), and the NOAA Alaska Fisheries Science Center (AFSC). Participating institutions on this cruise include NOAA-PMEL, AFSC, Penn State, the National Marine Mammal Laboratory (NMML), and the University of Alaska (UAF). This interdisciplinary study helps scientist better understand the overall marine environment of the North Pacific. This understanding will lead to a better management of the fishery resources of the North Pacific Ocean and the Bering Sea.

To ensure that time at sea is maximized for data collection, a day or so before leaving Seward, Alaska, the science crew begins assembling their various monitoring instruments under the directions of Chief Scientist for this project, William (Bill) Floering, PMEL.

Some of the equipment that will be deployed includes an Acoustic Doppler Current Profiler (ADCP), which measure speed and direction of ocean current at various depths. This data helps physical oceanographers determine how organisms, nutrients and other biological and chemical constituents are transported throughout the ocean. Argos Drogue drifters will also be deployed to help map ocean currents. Conductivity, temperature, and depth (CTD) measurements will be conducted at multiple sites providing information on temperature and salinity data. Additionally, “Bongo” tows will also be made at multiple locations which will allow for the collection of zooplankton. The results of this sampling will be used to characterize the netted zooplankton and help to monitor changes from previous sampling events. In future blogs I will describe these instruments in greater detail.

The furthest extent of our mission into the Bering Sea is very much weather and ice dependent with much variation this time of the year in the North Pacific Ocean. Current ice map conditions can be found at http://pafc.arh.noaa.gov/ice.php.

Operation Area

Personal Log

As I rode in the shuttle bus from Anchorage to Seward, Alaska on Friday, April 27, and then onto the pier where the Oscar Dyson was docked, I was immediately impressed by its size and overall complexity.

Upon arrival I was met by Bill Floering, Chief Scientist on the cruise. He gave me a tour of the overall ship and then I settled into my room, a double. Just like being back in college myself, and being the first to the room, I had my choice of bunks and therefore selected the lower bunk (I did not want to fall out of the top bunk if the seas turned “rough”). Arriving early provided me time to become oriented on the vessel given that I have never been aboard such a large ship before. I also had the opportunity to walk into Seward, AK, with a member of the science team, for a dinner downtown with extraordinary views of the surrounding mountains.

My stateroom!

On Saturday, April 27, the rest of the science crew arrived and my roommate, Matthew Wilson, moved in. Matt is from the Alaska Fisheries Science Center (AFSC) based in Seattle, Washington. That evening we traveled into town again for another great dining experience…halibut salad with views of Resurrection Bay.

Matt Wilson from the Alaska Fisheries Science Center.

Sunday, April 28, was a busy day of sorting and setting up various instruments for deployment. Winds were very strong, with snow blowing over the peaks of the mountains, glistening in the brilliant sunshine.

Scott McKeever from the Alaska Fisheries Science Center.

Installing instruments — Here I am helping to install instrumentation.

: View of Seward Harbor.

Monday, April 29, our day began with a safety meeting followed by our science meeting. At that time we were assigned to our work shift. I will be working from 12 midnight to 12 noon each day during the cruise. Once the ship sets sail, the science crew is working 24 hours per day!

Science team meeting with Bill and crew. — Science team meeting with Bill and Survey Tech Douglas Bravo.

At 1500 hours we set sail! The Journey begins!

Rita Salisbury First Day at Sea, April 15, 2013 (teacheratsea.wordpress.com)

September 22, 2003March 18, 2021

Nancy Lewis, September 22, 2003

Nancy Lewis
Onboard NOAA Ship Ka’imimoana
September 15 – 27, 2003

Mission: Tropical Atmosphere Ocean (TAO)/TRITON
Geographical Area: Western Pacific
Date: September 22, 2003

Sunrise: 0610
Sunset: 1817

0515: 4 N CTD

0900: Shellbacks on bow

1215: Deploy Test Wind Buoy

Repair 5 N 140 W Buoy

SOLO

Weather Observation Log

Latitude: 4 degrees., 22.7’ N
Longitude: 139 degrees, 58.8’ W
Visibility: 12 nautical miles (nm)
Wind direction: 160 degrees
Wind speed: 10 knots
Sea wave height: 2-3 feet
Swell wave height: 4-6 feet
Sea water temperature: 28.0 degrees C
Sea level presuure: 1013.0 mb
Dry bulb pressure: 27.8 degrees C
Wet bulb pressure: 24.6 degrees C
Cloud cover: 4/8 Cumulus, altocumulus, cirrus
Air temperature: 27.8 degrees C

Science and Technology Log

I promised that I would return to a discussion of the ADCP, or Acoustic Doppler Current Profiler. You can see from the Daily Log’s Plan of the Day when these were deployed, but they are deployed at the following locations: (0-147 E, 0-165 E, 0-170 W, 0-140 W). On which of these locations did we deploy the ADCP on this leg of the cruise?

These moorings are subsurface, and the data is only available after their recovery. Typically, the depth is 300 meters, and these buoys use the Doppler effect to gather data on ocean currents at that depth. I have posted several pictures on the website of the ADCP, and to me, it looks like a satellite when it was on board the ship. In the water, it looked like a big orange fishing bobber.

The ADCP (Acoustic Doppler Current Profiler) looks like a satellite when it is on board the ship….

… and like a big orange fishing bobber when it’s in the water.

Our buoy ops (operations) are beginning to wind down, and we recovered no TAO buoy today, as you can see from the plan of the day. There was a repair done to the 5 N 140 W buoy. A whole group went out to do that, and used the time while out at the buoy to do a little fishing. Two large fish came back on the RHIB, a yellow-fin tuna and a mahi-mahi. Kamaka was preparing the fish by cutting filets and making poke for tomorrow’s lunch.

I’d like to make available for teachers a lesson plan submitted by Suzanne Forehand from Virginia Beach City Public Schools. Because the schools have been closed due to the hurricane, it is not available as yet on the web. Teachers may request a copy from me, and I will send it as an attached file to an e-mail. I would like to thank Ms. Forehand for her collaboration on this project, andI hope that their electricity is restored soon. I look forward to hearing from the students at Plaza Middle School in Virginia Beach.

Personal Log

Oh, the life of a lowly Wog! Traditionally, those who have crossed the equator at sea for the first time are treated to a variety of secret initiation ceremonies where one is designated a “wog”. Shellbacks are those people who have already made the passage, and it is their delight to devise various tortures to inflict on the wogs. The 6 of us on board here were ordered up on the forward deck early this morning, and the fun began. I cannot give away any of these secrets, but suffice it to say that we all got a saltwater shower. From here on until we complete the initiation, we have to wear our clothes in ridiculous ways, and bow and scrape to the honorable shellbacks. At the end of several days of this entertainment for all the shellbacks, we then become a shellback ourselves and will be issued certificates and a card that we will hold on to forever to avoid having to endure the same in the future. In the 19th century this tradition was carried to extremes with such measures as keel-hauling the wogs, and some very serious, life-threatening acts of hazing. It is toned way down from those days, and all is done with a spirit of fun and good humor.

I have been busy looking at the photos I have taken on the digital camera, and of course selecting ones to be sent to Maryland to be posted on the website. There were various glitches today with the computer I am working on, so my work had to be done in fits and starts throughout the day.

Tom and I played 2 games of sequence this evening against the CO and Doc and we won the championship! The competition is fierce around here because the winners get a T-shirt or cap from the ship’s store. I guess I’ll find out if it was wise to beat the Captain hands down like that. I am scheduled to play him next in Scrabble.

Question of the Day: What is the origin of the word “hurricane”?

Aloha until tomorrow!

Nancy Lewis

September 19, 2003March 18, 2021

Nancy Lewis, September 19, 2003

NOAA Teacher at Sea
Nancy Lewis
Onboard NOAA Ship Ka’imimoana
September 15 – 27, 2003

Mission: Tropical Atmosphere Ocean (TAO)/TRITON
Geographical Area: Western Pacific
Date: September 19, 2003

Plan of the Day:

0700: Recover /Deploy Equatorial ADCP
Recover CO2 Buoy (if there) OR
Deploy CO2 Buoy ( if Buoy is missing)

Weather Observation Log: 0100

Latitude: 0 degrees, 0.7′ N
Longitude: 140 degrees., 2.3′ W
Visibility: 12 nautical miles (nm)
Wind direction: 120 degrees
Wind speed: 21 knots
Sea wave height: 3-5 feet
Swell wave height: 5-7 feet
Sea water temperature: 26.0 degrees C
Sea level pressure: 1011.2 mb
Dry bulb pressure: 26.0 degrees C
Wet bulb pressure: 23.8 degrees C
Cloud cover: 3/8 Cumulus, altocumulus

Science and Technology Log

The equator! For me as for most people, it has always just been “that line around the globe,” but now that I am out here on this project, I realize that the equator defines more than just the northern and southern hemispheres of the earth. It is here that the ocean currents are being intensively studied in order for us to understand the relationship between the oceans and climate. The 1982-83 El Nino was not predicted by scientists, and it had far-reaching, damaging effects on such diverse places as South America and Australia. It was then that NOAA funded the Tropical Ocean Global Atmosphere project that is the TAO/Triton array. Approximately 50 of the buoys are maintained by the U.S. and the other 20 are maintained by Japan. It took 10 years to complete and in essence, it is a 6,000 mile antennae for scientists to monitor conditions in the equatorial Pacific.

Normally, the trade winds blow from east to west, but in an El Nino event, the situation is reversed.

The phenomenon has long been observed by South American fisherman, and usually occurs around the time of Christmas, hence its name which means “Christ child.” The great ocean currents are moved by the wind, but around the equator, there are counter, below-sea currents. Instruments in the TAO/Triton array are involved in collecting important data on these below surface currents.

Each TAO buoy is moored to the bottom of the ocean using steel cable surrounded in plastic and railroad wheels are the anchor. At various depths on the Nilspin, temperature sensors called thermistors are strapped to the cable. The cable conducts a signal to the surface of the buoy. These cables can become damaged (by sharks biting them!) or otherwise degraded, and then the signal will be corrupted. Thus, there is the need for the periodic maintenance which is the main mission of the KA’IMIMOANA.

In addition, some of the buoys are equipped with CO2 sensors, which measure the amount of dissolved CO2 in the water, and which can then be used in studies of global warming. The buoy which we retrieved today stopped working shortly after it was deployed, and it was not known if it had broken free or what had happened. As it turned out, the buoy was there, and has been replaced with a fully functioning buoy. Right now, I am looking at innards of that CO2 sensor, which is in the computer lab and is being analyzed by the Chief Scientist.

Personal Log

Early this morning, we recovered the ADCP, which is a subsurface buoy. Shortly thereafter, we deployed a new ADCP. ADCP stands for Acoustic Dopplar Current Profiler, and this instrument is used to record data on the below surface currents. I will spend time later discussing this buoy, which looks like a giant orange ball.

I spent much of the day catching up on my daily logs, downloading photos and making several video clips to send to the website. It appears that the hurricane did a number on the East Coast, and we probably will not have email communication until at least tomorrow. I have been very happy to get some good questions from the students at Na’alehu School on the Big Island, and I am looking forward to hearing from many more of you next week.

I also spent time today chatting with the Chief Boatswain, Kamaka, a very hard working Hawaiian young man who spreads a lot of aloha wherever he goes. I have invited Kamaka to come to my school when we get back to Hawaii since he is planning to visit the Big Island. His girlfriend is Marquesan and lives on Nuku Hiva.

The sunset this evening at the equator was stunningly beautiful, and there was a rainbow under some misty clouds in the east. I am hoping my photo was able to capture it for you all. We shall remain here at the equator overnight, and I am looking forward to the gentle rocking of the ship once I tumble into my berth later this evening.

Question of the Day: What is the Coriolis effect and how does it relate to winds and ocean currents?

Aloha from the KA’IMIMOANA!

Nancy Lewis

August 26, 2002March 18, 2021

Diane Stanitski: Day 16, August 26, 2002

NOAA Teacher at Sea

Diane Stanitski

Aboard NOAA Ship Ka’imimoana

August 16-30, 2002

Day 16: Sunday, August 26, 2002

Today we are at the equator!!! (0° latitude, 140° west longitude)

The FOO (Field Operations Officer)’s quote of the day:

“The greatest thing in the world is to know how to be self-sufficient.”
– Michael de Montaigne

Weather Log:
Here are our observations at 1400 today:
Latitude: 0°02’N
Longitude: 139°56’W
Visibility: 12 nautical miles (nm)
Wind direction: 140°
Wind speed: 9 kts
Sea wave height: 3-4′
Swell wave height: 5-7′
Sea water temperature: 27.1°C
Sea level pressure: 1010.3 mb
Cloud cover: 4/8, Cumulus, Altocumulus

Hurricane Fausto is currently located at 21.3°N, 132.7°W and continues to diminish in strength. It has sustained winds of 60 kt, gusting to 75 kt. and is moving toward 300° (WNW) at 15 kt. Its central pressure has risen to 987 mb.

Greeting:

First of all, I’d like to say WELCOME to my classes at Shippensburg University. Today is the first day of classes there and I want to acknowledge those people who are helping to cover my classes and are also assisting with the link between me and my students this week and next. Those who have helped tremendously include Drs. Niel Brasher, George Pomeroy, William Rense, Christopher Woltemade, and Holly Smith. Thank you!

I have already received email messages from many of you in my classes. Remember, part of your assignment for this first week is to email me at least 3 times asking me questions about the ship’s operations, science on board, or anything else that you feel would be of interest to you. Please read all of my logs, check out my photos, watch the previous videos, and follow the path that the ship takes across the Pacific Ocean. We’ll be referring to all of the information shared on the web throughout the semester. Welcome to the Pacific Ocean – glad you could join me!

Science and Technology Log:

I awoke and immediately starting preparing for our second general broadcast of the trip. Seven guests were scheduled to be interviewed during this broadcast. They did an excellent job. Unfortunately, Dave Zimmerman was immersed in the operations of the morning Acoustic Doppler Current Profiler (ADCP) retrieval and deployment, and so couldn’t join us for a short interview. I’ll try to catch him again when things aren’t quite as hectic. Overall, the show went well and I’ll spend the rest of the day preparing for the next three broadcasts with my students in Introduction to the Atmosphere, Meteorology, and the Atmospheric Environment at Shippensburg University. I’m anxious to meet everyone in the classroom from the ship to share some of the things that I’ve been learning on board the Ka’imimoana. Please check out all of the videos on this web site to see who I’ve interviewed in the past. The ship’s scientific equipment and research, and my interactions with scientists using them, will definitely add to what I teach in the classroom, which should make for a more interesting and valuable experience for all of you.

Here are some interesting facts about the ADCP. It is a subsurface mooring, which means that it is anchored to the bottom of the ocean but remains nearly 300 meters below the surface of the water, and it measures current velocity profiles. It is a large round floating orange sphere (see photo logs) that measures the velocity of ocean currents in approximately the upper 250 meters of the ocean using the Doppler effect. Today, after triggering the acoustic release separating the anchor from the old ADCP that was being replaced, the instrument emerged at the surface of the water, was spotted, and then dragged through the water to the ship where it was hoisted up with one of the ship’s cranes onto the fantail. The thousands of meters of line were then reeled in and later deployed again with a replacement ADCP attached. The instrument uses the Doppler effect meaning that there is a change in the observed sound pitch that results from relative motion of an object, in this case water. If something is coming toward you, the wave frequency appears to be higher and if something is going away from you, the frequency of waves appears to be lower. The example that is always used is that of a moving train. The train’s whistle has a higher pitch when the train approaches and a lower pitch when it moves away from you. The change in pitch is directly proportional to how fast the train is moving. If you measure the pitch and how much it changes, you can calculate the speed of the train.

ADCPs use the Doppler effect by transmitting sound at a fixed frequency and listening to echoes returning from waves and sound scatterers in the water, such as small particles or plankton reflecting the sound back to the ADCP. Scatterers float in the water and on average they move at the same horizontal velocity as the water. When these scatterers move toward the ADCP, the sound heard by the organisms is Doppler-shifted to a higher frequency. The ADCP uses four beams to obtain velocity in many dimensions. Overall, it’s an amazing instrument.

The equatorial buoy was retrieved tonight and a new one will be deployed tomorrow. That buoy will be dedicated to the Grace B. Luhrs Elementary School and Shippensburg University. It will be signed by the Captain, Chief Scientist, and me, and will be located at 0°, 140°W for the next year. Shippensburg’s name will be on the Pacific for at least 365 days!

Personal Log:

Most of my afternoon and evening was spent answering emails and preparing lesson plans. I am looking forward to tomorrow’s activities but have many miles to go before I sleep. Keep in touch!

Question of the day:

At what heights in the atmosphere are altostratus or altocumulus clouds found?

One of my Meteorology students, Steve Osmanski, provided the correct answer to my previous question of the day, “what are crepuscular rays?” His answer is: “They are the classic ‘sunburst’ effect caused when sunlight is blocked by a cloud and appears to be “streaming in rays” around the shadow. They are visible from scattering of sunlight by dust or water droplets, and appear to diverge as a trick of perspective.” Excellent, Steve! I look forward to having you in class!

Until tomorrow…
Diane

March 12, 2002March 18, 2021

Dana Tomlinson: Day 12, March 12, 2002

NOAA Teacher at Sea

Dana Tomlinson

Aboard NOAA Ship Ka’imimoana

March 1 – 27, 2002

Date: Tuesday, March 12, 2002
Lat: .5°S
Long: 110°W
Seas: 2-4 ft.
Visibility: unrestricted
Weather: partly to mostly cloudy
Sea Surface Temp: 77-82°F
Winds: N/NE 5 knots
Air Temp: 88-76°F

As it turns out, the ADCP (Acoustic Doppler Current Profiler) was rigged up to deploy when I went outside this morning. The scientists had determined a new method of having it enter the water so there would be even less likelihood of anything going wrong. And they did a great job, because it was a very easy deployment. Mission accomplished – there’s an ADCP successfully collecting data on the equatorial currents at 110°W for the next year.

There was even more excitement to come for me, however. I had the privilege of being the first Teacher at Sea to ever have a buoy dedicated to her school. At 1130 today, Cdr. Tisch, Chief Scientist McPhaden and I each signed a large NOAA sticker on which we had written “Emory Elementary School, San Diego CA.” The gentlemen placed it on the plastic covering of the instrumentation and when it was deployed at the equator 110°W, that sticker actually kept its face to us until we could no longer read it. What’s truly amazing is that very buoy was the very first buoy that NOAA ever deployed in 1979. Our school is very honored.

The deployment of the Emory buoy took quite a while today because of the many fairings that the crew had to put on the wire line that goes down 250m below the buoy. Tomorrow is also a busy day on board. We are doing several CTD casts (Conductivity, Temperature and Depth), and we will be going by the buoy at 2°S to check on it, but we’re not recovering it.

Question of the Day:

What is a fairing and what does it do?

Answers of the Days:

Due to the weekend, there are several questions to catch up on. Here we go:

From Friday: No one answered this one correctly, so I’m going to give it to you. GMT is Greenwich Mean Time. It is 7 hours ahead of us here in Mountain Time and it is where all time is based because it is the 0 degree line of longitude. In nautical letters, zero is Zulu, hence, Zulu time. So, if it’s 9pm here in Mountain time, in GMT it is 4am.

From Saturday: Ditto on no answer for this one (come on you guys!!).
TAO stands for Tropical Atmosphere Ocean.

From Sunday: Karen R. in San Diego knows that MBARI stands for Monterey Bay Aquarium Research Institute. And Vanessa P.(again!) in San Diego knows that pelagic means of the open ocean. And Brian R. in San Diego knows that chlorophyll is the green matter found in certain cells of plants, algae and some bacteria and it’s important because it changes light energy into chemical energy.

Til tomorrow,
🙂 Dana

March 11, 2002March 18, 2021

Dana Tomlinson: Day 11, March 11, 2002

NOAA Teacher at Sea

Dana Tomlinson

Aboard NOAA Ship Ka’imimoana

March 1 – 27, 2002

Date: Monday, March 11, 2002
Lat: 0°
Long: 110°W
Seas: 2-5 ft.
Visibility: unrestricted
Weather: cloudy, rain possible
Sea Surface Temp: 77-82°F
Winds: N/NE 5 knots
Air Temp: 88-77°F

What an interesting day, all the way around. Weather-wise, we awoke to clear skies, with clouds on the horizon and we could tell it was going to be hot. By 9am, I could feel the backs of my legs burning with my back to the sun. I went in for lunch and came out and it was totally clouded over and a few minutes later, it was raining! Not drizzling – raining. Welcome to the equatorial Pacific!!

Yes, we made it to the Equator! My days as a Pollywog are numbered. Shellback is coming soon. Today, there were several important events going on onboard. Most importantly to me was our first live webcast. This was an exclusive to my school only and fortunately, was a technical success! It was actually a pretty perfect broadcast, a great way to start. All of the schools that have contacted either the NOAA offices or myself have received word about future live webfeeds. Once again, if there are any teachers out there who would like a live feed right into your classroom or any computer at the school that has an internet connection and RealPlayer (a free download), just let me know asap and we’ll get you the info you need.

The other important events on board today were another buoy recovery (more barnacles!!), a ADCP recovery/deployment and a deep CTD cast (to 3600 meters). The buoy was recovered, but it was 30 miles from where it should have been due to the strong currents at the equator. We will deploy the new one tomorrow morning. It will be a very special buoy – the first one ever dedicated to a school. It will have a sticker on it signed by the Commander, the Chief Scientist and me, dedicated to Emory Elementary! Neat, huh?!

The ADCP is an Acoustic Doppler Current Profiler that’s been in the water for the last year. This is a big, round orange device (a little bit bigger that a weather balloon) with instrumentation on it that records the currents. There are 4 of them across the equator resting at different depths. It is anchored so that it rests 250 feet below the surface and periodically sends sonar waves up to the surface that bounce off of the surface and the plankton above and somehow that helps to record the currents. The information is stored in the device until it is recovered and then the data is learned. Like the buoys, it has an acoustic release device on it that releases it from the anchor when remotely told to do so and it floats to the surface.

The recovery went perfectly. We had a bit of trouble with the deployment, however. Hey, sometimes, things happen and this was one of them. Just as the crew was carefully loading it into the water, a wire snapped and the ADCP fell into the water untethered. It had to be rounded up just like the old one and brought back up on deck. Presently, it’s still sitting there as the scientists decide whether or not to deploy it tomorrow or to wait. Stay tuned.

Question of the Day:

Above I mentioned being a Pollywog and being a Shellback. What do I mean?

Answer of the Day:

Once again, since the logs weren’t posted over the weekend, let me give the GMT/Zulu question one more day. 🙂

Til tomorrow,
🙂 Dana

Tag: Acoustic Doppler Current Profiler

Frank Hubacz: Our First Day at Sea, April 29, 2013

Related articles

Nancy Lewis, September 22, 2003

Nancy Lewis, September 19, 2003

Diane Stanitski: Day 16, August 26, 2002

Dana Tomlinson: Day 12, March 12, 2002

Dana Tomlinson: Day 11, March 11, 2002