calibration – NOAA Teacher at Sea Blog

August 20, 2023August 23, 2023

Germaine Thomas: Hurry up and Wait, or What to do when the Weather Sets In, August 16, 2023

NOAA Teacher at Sea

Germaine Thomas (she/her)

Aboard NOAA Ship Oscar Dyson

August 7 – August 21, 2023

Mission: Acoustic Trawl Survey (Leg 3 of 3)
Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska
Date: Wednesday, August 16, 2023

Weather Data
Lat 59.47 N, Lon 144.1 W
Sky condition: Cloudy with Rain
Wind Speed: 22.62 knots
Wind Direction: 125.44°
Air Temp: 14 °C

Science and Technology Lab

While on the third leg of our cruise we have had a lot of weather delays, so when the going gets rough the Oscar Dyson science team calibrates! Plus they do not hesitate to work on a couple special projects. No time is wasted. In a secluded bay, waiting for the storm to pass, lots of work can be done to further science.

As I mentioned, this summer has been cold, dark, rainy, and windy. As a fisher person who works in this environment, I cannot overstate how important the internet has become with weather apps like Windy. They accumulate data from oceanic buoys, local weather stations, and satellite images to create a picture like the one you see below.

a screenshot showing simple political map of the Gulf of Alaska coastline. it has been colored with a scale to indicate wind speed. small white dashes are scattered through the image, showing the wind blowing up from the southwest, into the center of the coastline, curving counterclockwise toward Anchorage. A few major locations are labeled with air temperatures: Anchorage: 59 degrees, Homer: 57 degrees, Kodiak: 55 degrees, Juneau: 55 degrees, Whitehorse: 59 degrees. — This image is from the weather app Windy. The white lines indicate the wind direction and the warmer colors are higher wind speeds.

The crew and scientists were able to be proactive in their decision to find a safe place to harbor and then could set up a work plan through the weather day.

Calibration of the Ships Echosounders

The Oscar Dyson’s echo sounders get calibrated about four times a year, at the start and end of the winter and summer field seasons. Because this is the last leg of the cruise, and we are nearing the end of the summer, a weather day is a good day to make sure they are working well

The first step in calibration is to set up down riggers on the starboard, port and aft decks.

Abigail, Robert, and Matthew pose for a photo in the wet lab, each holding a downrigger. The downriggers look like heavy-duty black fishing poles that can be secured onto the deck railings. Abigail is wearing a red light headlamp. — From left to right Abigail McCarthy, Robert Levine and Matthew Phillips, part of the night crew, head outside to place the down riggers.

Once placed, the downrigger lines are very cleverly connected underneath the boat, so all three lines meet.

a downrigger, which looks like a heavy-duty black fishing pole, attached to a railing of the ship. a fishing line extends down from the end into the water, angled back toward the ship to meet up with the other lines. The water is a calm, gray-blue, with fog-shrouded mountains not far in the distance. — Downrigger mounted on a railing

Where all three lines meet, a single line is suspended directly down underneath the keel of the boat where the echo sounders are located. The down line has a tungsten carbide sphere suspended above a lead weight. The scientists use the known target of the sphere and the known properties of the water column to figure out the difference between expectations and reality in their calibration. The tungsten carbide sphere works extremely well for calibration because it is extremely dense when compared to water, has a known sound reflection, and allows calibration at multiple frequencies.

photo of a computer screen; on the left, many circles (most blue, some white, one red) within a larger circle; on the right, a table full of numbers. — Pictured above is a screen scientists see as they are moving the sphere around for calibration.

The picture is showing a black circle representing the transducer face as observed from above. The blue dots represent individual measurements of the reflected echo of the calibration sphere as it is moved around in the transducer beam. Using this calibration software the scientists can evaluate the measurement sensitivity and the beam characteristics of the echo sounders.

Calibrating the acoustics was not the only event that happened while weathered deep in a fjord arm of Nuka Bay.

The MiniCam

While waiting out the weather, other members of the science team had a chance to work with a new piece of equipment called a minicam.

small underwater camera apparatus sitting on deck — The MiniCam, pictured above, has two stereo cameras which can film marine organisms.

The purpose of this camera is to connect the images it records to the backscatter shown with the Oscar Dyson‘s echo sounders. Again, backscatter, as I mentioned in the previous blog, are images that are produced when the echosounders’ different frequencies are reflected back to the ship. The images created by sound are shown on a computer screen and can be used to identify different species of fish or other marine organisms. The images need to be verified by either the minicam or trawl sampling. Scientists want to make sure that the length and species of what they see in the camera can relate to the scaling of the backscatter. The minicam was deployed by scientists and the crew several times to look at the fish and euphausiids in the water column, while we waited out the bad weather.

Germaine and another crewmember, wearing life vests, hard hats, and boots, stand on deck in the evening. the minicam, attached to cables extending beyond the top of the image, sits on deck near the railing, awaiting deployment. In the background, we can just barely see dark blue water, and a darker blue mountain, hidden in fog. — Getting ready to suspend the MiniCam before it is lifted over the side of the boat from the Hero deck.

Recreational Fish Finders “Little Pingers” Project

This is a project by NOAA oceanographer Robert Levine. The echosounders that are suspended below the Oscar Dyson are extremely precise and expensive. Robert and a colleague want to compare the echosounder’s data/readout for recreational fish finders to the echosounders on the Oscar Dyson. There are situations where scientists would love to monitor fish and marine organisms’ populations, but may not need the accuracy and precision of the scientific Simrad echosounders.

Robert, wearing a life vest, works on a laptop inside a storage area with one door open to an outer deck. he appears to be sitting on an overturned bucket. in front of him, another overturned bucket props up equipment (probably fish finders). Behind Robert, we see other equipment, hoses, life preservers, a fire extinguisher, a ladder. — Robert Levine working with the ” Little Pingers.” Environments on board a ship can be challenging to work in, as seen here.

They also might not be able to recover the fish finders, so having them less expensive is very important.

At this point they are just collecting data and monitoring performance with the recreational fish finders, affectionately called “little pingers.” Later in the project they will do more of a data comparison to the Oscar Dyson‘s echo sounders.

Personal Log

On board a ship, one way to keep the crew’s spirits up in bad weather is excellent food. According to the people I have worked with so far on the cruise, the meals on this leg of the acoustic-trawl survey have been amazing.

Meet The Dream Galley Team

Rodney and Angelo pose for a photo against a wall in the mess. They are standing in front of a coffee machine. Rodney wears an Oscar Dyson trucker cap. Angelo is wearing a black chef's uniform. — From left to right, Rodney Bynum and Angelo Santos

Meet the Dream Galley Team. From left to right, Rodney Bynum and Angelo Santos. These men share a passion for food and see how it brings smiles to the faces of their customers, friends, and family. Both have fathers who worked on ships in the Steward Department. Rodney fondly remembers his father bringing home exotic food from all over the world. His father inspired him to open a Soul Food restaurant in Norfolk, Virginia. Years later, Rodney decided to take his culinary career in a different direction: cooking on a ship. The Oscar Dyson was his first time working on a ship and he has really enjoyed it thus far. The crew loves his congenial personality, mad cooking skills, and awe-inspiring work ethic.

Angelo started cooking at the age of 11, often helping his mom roll lumpia (Filipino egg rolls) and make other traditional Filipino food while religiously watching Giada de Laurentis, Emeril Lagasse, and Ina Garten on Food Network. Angelo grew up in San Francisco and rural Oregon, spent 3 years in San Diego, and is now based in Oregon once again while traveling the world for work. In Oregon, he decided to major in Culinary Arts and graduated with his associate’s degree after going through Linn-Benton Community College’s Culinary program. Angelo mentioned, “culinary school isn’t required, but it helps you gain a fundamental understanding of cooking to prepare you for the real world.” He recommends trying out a restaurant job before spending money on tuition for culinary school.

East Coast meets West Coast aboard the Oscar Dyson. Both men have solid fundamentals in cooking from their years of experience as restaurant chefs. Angelo is the Chief Steward while Rodney is the 2nd Cook. The Chief Steward is in charge of galley operations while the 2nd cook provides breakfast and assists as needed. Chief Steward is like an Executive Chef position on land while 2nd cook is like a breakfast cook/prep cook/dishwasher. Rodney and Angelo often collaborate for menu ideas and feed off each other’s passion for delicious food.

Both of them enjoyed high school and had lots of advice for students looking into a career in Culinary Arts. As I interviewed them, they’d often finish each others’ sentences in agreement.

Rodney: “If you’re looking to become a good chef, don’t be afraid to taste everything, including food that may not be familiar to you. Every job in the kitchen matters, whether it’s the prep cook, dishwasher, or executive chef. Learn every position and never stop learning.”

Angelo attended culinary school shortly after graduating high school, so he found it to be stressful and chaotic, but very rewarding. He mentioned, “Focus as much as possible on having a good work-life balance. Find the joy in simple pleasures, take care of your mental health, and make friends outside of work. Work on networking with peers who share your passion for food as well as people outside of your cohort. Connections can help a lot.” Angelo enjoys cooking on ships because the compensation was very good. The only chef jobs on land that compare to this salary are executive chefs at very high end venues and private/personal chefs. Being able to travel around the world on business was a cool perk of being a chef at sea.

Overall, both men agreed that some of the best moments of pursuing a career in the food industry have been about seeing the joy that good food brings to people. Life is too short to not eat well and this is especially appreciated when one works on a ship. It makes all the difference for the morale of a ship to know that while you’re away from your loved ones, you can still eat well.

Finally, I have to give Angel credit for helping me write the sections about the “Dream Galley Team,” not only is he a great cook but also a fantastic writer.

top down view of a purple mug on a red table containing a latte with foam designs — This beautiful latte was made by Angelo Santos on the *Oscar Dyson*

June 19, 2023June 19, 2023

Laura Guertin: Collecting Data: Acoustic Survey, June 19, 2023

What looks like a long fishing rod attached to a ship's rail on the ocean

NOAA Teacher at Sea

Laura Guertin

Aboard NOAA Ship Oscar Dyson

June 10 – June 22, 2023

Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska

Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area
Location (2PM (Alaska Time), June 18): 55^o 15.3391′ N, 160^o 17.8682′ W

Data from 2PM (Alaska Time), June 18, 2023
Air Temperature: 8.9 ^oC
Water Temperature (mid-hull): 7.7^oC
Wind Speed: 4 knots
Wind Direction: 182 degrees
Course Over Ground (COG): 356 degrees
Speed Over Ground (SOG): 12 knots

Date: June 19, 2023

Acoustic fisheries surveys seek to estimate the abundance and distribution of fish in a particular area of the ocean. In my case, this Summer Survey is looking at walleye pollock in the Gulf of Alaska. How is this accomplished? Well, it’s not through this method:

The Alaska walleye pollock is widely distributed in the North Pacific Ocean with the largest concentrations in the eastern Bering Sea. For this expedition, Oscar Dyson is traveling to specific regions in the Gulf of Alaska and running transects perpendicular to the bathymetry/contours (which are not always perpendicular to the shore) to take measurements using acoustics and targeted trawling to determine the abundance and distribution of walleye pollock which informs stock assessment and management models. For this blog post, let’s focus on how and why we can use acoustics to locate fish.

A map of the distribution of walleye pollock in the waters around Alaska. Alaska is centered in this map, but not disconnected from adjacent portions of Canada, and portions of Russia are visible to the east. Colors representing topography are visible, emphasized on the land of Alaska and depicted faintly on Canada and Russia. The ocean is depicted as a solid blue. We see latitude and longitude lines at ten degree intervals. We can see labels for the Beaufort Sea (north of Alaska), Chukchi Sea (northwest), Bering Sea (west), Bristol Bay (southwest), Gulf of Alaska (south and southeast.) The polygon representing the distribution of pollock is shaded with diagonal red lines. It starts in the Chukchi Sea, extends southwest out to the Bering Sea, and curves around the Aleutian Islands, hugging the coastline around the Gulf of Alaska. — Walleye pollock (*Gadus chalcogrammus*) are distributed broadly in the North Pacific Ocean and eastern and western Bering Sea. In the Gulf of Alaska, pollock are considered as a single stock separate from those in the Bering Sea and Aleutian Islands. Image from Alaska Department of Fish and Game.

A screenshot of an electronic nautical chart of the area around the Alaska Peninsula. Overlain on the chart are straight blue lines connecting blue points in a boxy meandering path in and out from the coastline, west to east. A few segments are red instead of blue. — An snapshot of a nautical chart with transects plotted. The first transect was run during Leg 1 on June 14 at the furthest location to the west, then the ship worked its way back east with approximately 40 nautical miles between transects. Once *Oscar Dyson* reached the Shumagin Islands, survey work shifted into this area..

Our story starts with the fish itself. Alaska walleye pollock have a swim bladder. The swim bladder is an internal organ filled with gas that allows a fish to maintain its buoyancy and stability at depth.

One interesting effect of the swim bladder is that it also functions as a resonating chamber that can produce and receive sound through sonar technology. This connection was first discovered in the 1970s, when low-frequency sound waves in the ocean come in contact with swim bladders and they resonated much like a tuning fork and return a strong echo (see WHOI’s Listening for Telltale Echoes from Fish).

illlustrated diagram of the internal anatomy of a boney fish. The swim bladder is located in the middle of the fish, beneath the long, skinny kidney and behind the stomach. — *Internal anatomy of a boney fish. From Wikipedia (CC BY-SA 3.0).*

Illustration of a survey ship on the ocean surface, with the ocean cutaway so that we can see a cone of sound pulses extending out from the ship's hull to the ocean floor. A school of fish is depicted in the middle of the water column, in the cone of sound. — *The sound pulses travel down into the water column, illustrated by the white cones here, and bounce back when encountering resistance.* *(from NOAA Fisheries)*

NOAA Fisheries uses echo sounding, which works by emitting vertical pulses of sound (often referred to as pings), and measuring the return strength and recording the time for the signal to leave and then return. Anything having a different density from the surrounding water (in our case – fish, plankton, air bubbles, the seafloor) can return a signal, or “echo”.

The strength or loudness of the echo is affected by how strongly different ocean elements reflect sound and how far away the source of the element is. The seafloor usually makes the strongest echo because it is composed of rock which has a density different than the density of water. In fish, the swim bladder provides a contrast from the water. In addition, each fish species has a unique target strength or amount of sound reflected to the receiver. The size and shape of the swim bladder influence the target strength. There is a different target strength to length relationship for each species of fish – the larger the fish, the greater the strength of the returning echo.

It’s important to note that echo sounders cannot identify fish species, directly or indirectly. The only way we know which fish species is causing a signal is based on trawl catch composition. There is nothing within the acoustic data that lets us identify fish species, even with the catch data. This is a subtle, but important, distinction. Acoustic data, particularly calibrated acoustic data, in tandem with the information from the trawl, definitely allows us to count fish.

Where is the echo sounder on Oscar Dyson? Look at the figure in the next section of this post – it’s a sketch of NOAA Ship Rainier, but the placement of the echo sounder is the same for Dyson. You can see a rectangular “board” that is extended down from the center of the ship. This is called – what else – the center board! Attached to the bottom of the center board are the echo sounders. When lowered, the echo sounders sit at 9 meters below the level of the sea (~4 meters below the bottom hull of the ship).

Did you know… Southern Resident killer whales use their own echolocation clicks to recognize the size and orientation of a Chinook’s swim bladder? Researchers report that the echo structure of the swim bladders from similar length but different species of salmon were different and probably recognizable by foraging killer whales. (reported in Au et al., 2010)

It starts with a calibration

*Typical setup of the standard target and weight beneath the echo sounder.* *(from NOAA Fisheries)*

Before we can begin collecting data, we need to calibrate the echo sounder. The calibration involves a standard target (a tungsten carbide sphere) with a known target strength. The calibration needs to be completed in waters that are calm and without significant marine life for the best results.

The sphere is suspended below the ship’s hull using monofilament lines fed through downriggers attached to ship railings. One downrigger is in line with the echo sounder on the starboard side, and the other two on the port side. This creates a triangle that suspends the sphere in the center of the echo sounder’s sound beam. By tightening and loosening the lines, the sphere can be positioned under the center of the sound beam and can also be moved throughout the beam. By doing an equipment calibration at the beginning and end of a survey, we can ensure the accuracy of our data.

One of the port side downriggers
A weight that goes at the bottom of the filament to ensure the calibration sphere remains below the echo sounder
The tungsten carbide sphere attached to the line, being lowered over the side

For further exploration

NOAA Ocean Service – Ocean Facts – How do scientists locate schools of fish?

Discovery of Sound in the Sea – How is sound used to locate fish?

NOAA Fisheries – Acoustic Echosounders–Essential Survey Equipment and Acoustic Hake Survey Methods on the West Coast

NOAA Ocean Service – Ocean Facts – What is sonar?

Science – Sounds like my favorite fish – killer whales differentiate salmon species by their sonar echoes

NOAA Fisheries – Sound Strategy: Hunting with the Southern Residents, Part 2

The Pew Charitable Trusts – Advanced Sonar Technology Helps NOAA Count Anchovy

August 7, 2019

Jessica Cobley: Recalibrating, August 6, 2019

NOAA Teacher at Sea

Jessica Cobley

Aboard NOAA Ship Oscar Dyson

July 19 – August 8, 2019

Mission: Midwater Trawl Acoustic Survey

Geographic Area of Cruise: Gulf of Alaska (Kodiak to Yakutat Bay)

Date: 8/6/2019

Weather Data from the Gulf of Alaska: Lat: 58º 44.3 N Long: 145º 23.51 W

Air Temp: 15.9º C

Personal Log

Currently we are sailing back across the Gulf of Alaska to the boat’s home port, Kodiak. I think the last few days have gone by quickly with the change of daily routine as we start to get all the last minute things finished and gear packed away.

Since my last post, the definite highlight was sailing up to see the Hubbard Glacier in Disenchantment Bay (near Yakutat). WOW. The glacier is so wide (~6miles) that we couldn’t see the entire face. In addition to watching the glacier calve, we also saw multiple seals sunbathing on icebergs as we sailed up to about a mile from the glacier.

We spent a few hours with everyone enjoying the sunshine and perfect view of the mountains behind the glacier, which form the border between the U.S. and Canada. We also had a BBQ lunch! Here are a few photos from our afternoon.

*Group photo of the science crew! Photo by Danielle Power*

Another surprise was showing up for dinner the other night to find King Crab on the menu. What a treat! Most people are now trying to get back on a normal sleeping schedule and so mealtimes are busier than usual.

king crab legs — *Our Chief Steward, Judie, sure does spoil us!*

Lastly, the engineering department was working on a welding project and invited me down to see how it works. On the first day of the trip I had asked if I could learn how to weld and this was my chance! They let me try it out on a scrap piece of metal after walking me through the safety precautions and letting me watch them demonstrate. It works by connecting a circuit of energy created by the generator/welding machine. When the end you hold (the melting rod) touches the surface that the other end of the conductor is connected to (the table) it completes the circuit.

Jessica welding — Wearing a protective jacket, gloves and helmet while welding are a must. The helmet automatically goes dark when sparks are made so your eyes aren’t damaged from the bright light. Photo by Evan Brooks.

Scientific Log

Before making it to Yakutat we fished a few more times and took our last otolith samples and fish measurements. Otoliths are the inner ear bones of fish and have rings on them just like a tree. The number and width of the rings help scientists calculate how old the fish is, as well as how well it grew each year based on the thickness of the rings. In the wet lab, we take samples and put them in little individual vials to be taken back to the Seattle lab for processing. Abigail did a great job teaching where to cut in order to find the otoliths, which can be tough since they are so small.

Jessica and pollock otoliths — *Our last time taking otolith samples from pollock. Photo by Troy Buckley*

Another important piece of the survey is calibrating all of the equipment they use. Calibration occurs at the start and end of each survey to make sure the acoustic equipment is working consistently throughout the survey. The main piece of equipment being calibrated is the echosounder, which sends out sound waves which reflect off of different densities of objects in the water. In order to test the different frequencies, a tungsten carbide and a copper metal ball are individually hung below the boat and centered underneath the transducer (the part that pings out the sound and then listens for the return sound). Scientists know what the readings should be when the sound/energy bounces off of the metal balls. Therefore, the known results are compared with the actual results collected and any deviation is accounted for in the data accumulated on the survey.

After calibration, we cleaned the entire wet lab where all of the fish have been processed on the trip. It is important to do a thorough cleaning because a new survey team comes on board once we leave, and any fish bits left behind will quickly begin to rot and smell terrible. Most of the scales, plastic bins, dissection tools, nets, and computers are packed up and sent back to Seattle.

Gear packed — *All packed up and ready to go! The rain gear also gets scrubbed inside and out to combat any lingering fish smell.*

Did You Know?

Remember when you were a kid counting the time between a lightning strike and thunder? Well, the ship does something similar to estimate the distance of objects from the ship. If it is foggy, the ship can blow its fog horn and count how many seconds it takes for the sound to be heard again (or come back to the boat). Let’s say they counted 10 seconds. Since sound travels at approximately 5 seconds per mile, they could estimate that the ship was 1 mile away from shore. We were using this method to estimate how close Oscar Dyson was from the glacier yesterday. While watching the glacier calve we counted how many seconds between seeing the ice fall and actually hearing it. We ended up being about 1 mile away.

Cheers, Jess

September 6, 2018September 9, 2018

Justin Garritt: Precision in Science is Key. Calibrating Day and Ship Tour, September 5, 2018

NOAA Teacher at Sea
Justin Garritt
NOAA Ship Bell M. Shimada
September 5, 2018

Topic Today: Calibrating the Equipment and ship tour

Geographical area of cruise: Seattle, Washington to Newport, Oregon

Today’s Location and Weather: Beautiful sunny skies calibrating in Elliot Bay, Seattle, Washington

Date: September 5, 2018

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Today’s blog will focus on calibration and a tour of the beautiful ship.

Calibration is the act of evaluating and adjusting the precision and accuracy of measurement equipment. It is intended to eliminate or reduce bias in an instrument’s readings. It compares the standard measurement with the measurement being made by the equipment. The accuracy of all measurements degrade over time by normal wear and tear. The purpose of calibration is to check the accuracy of the instrument and with this information, adjustments can be made if it is out of calibration. The bottom line is that calibration improves the accuracy of the measurement device which improves quality.

We calibrate many things in life. For an example, many teachers at my school have smart bo images ards or promethean boards. These boards are interactive white boards that allow teachers to teach using more interactive tools. As a math teacher, I have had a promethean board in my classroom which acts like a large touch screen computer that I take notes on, teach lectures on, give student feedback on, and play math games on.

A teacher calibrating their smart board in a classroom

They have improved the learning experience for students in my class and across the globe. In order for the screen to work most accurately, we must perform routine calibrations on the board. If we don’t, there is often errors and where we touch the screen is not what actually shows up on the board. When these errors begin to occur, we must calibrate the board or else we won’t be as accurate when writing on the board.

cal2

Police officers and military personnel must also use calibration in their work. Officers must routinely calibrate their weapons for accuracy. When at a safe and secure range, officers will “site-in” their weapons to determine if their scope is accurate. They will then make modifications to their weapons based on the calibration tests. This is another form of calibrating that improves the quality and accuracy of the equipment.

On board the NOAA Ship Bell M. Shimada, calibration typically happens at the start and end of most legs. Sometimes the Chief Scientist will also make the decision to calibrate mid-leg. For the past two days we have been spending 12 to 15 hours per day calibrating the equipment to ensure the most accurate research can be completed and we can meet the goals of the leg.

All of the scientists aboard

Me using a down rigger during calibration

Calibrating the equipment is an interesting process that involves the teamwork of all the scientists on board. The process begins with three scientists setting up down riggers on the outside of the boat. Two are set up on starboard side (right side of the ship) and one is set up on port side (left side of the ship). This creates a triangle which will allow the calibration sphere or what I like to call, “the magic sphere” to move in whatever direction needed. This same triangle shaped design is used to move cameras that fly above players in the Superbowl.

This same triangle shaped design is used to move cameras that fly above players in the Superbowl.

Another image of camera that flies above Superbowl

dafonbjedkjjpicd — The picture above shows how three lines suspended from down riggers that are attached to the sphere.

The pictures (with captions) show the process step by step.

Scientist Steve de Blois setting up one of the down riggers

Scientist Dezhang Chu prepares the “magic sphere” before dropping it in the water for calibration

Scientist Dezhang Chu drops the “magic sphere” in the water

Dropping the sphere in the water for calibration

Chief Scientist Rebecca Thomas checking in with her team

The three-line triangle shape is used to maneuver the “magic sphere” below the boat during calibration

Scientist Dezhang Chu leads the calibration from the acoustics lab

Scientist Dezhang Chu communicates with the team at the down riggers on where to move the “magic sphere” for calibration

This screen monitors where the sphere is under the ship. The goal during calibration is to move the sphere is all four quadrants of the screen.

We calibrated for two full days. It was surprising how long the process took. After explanations from the many scientists on board I learned that the process is so long because we are assessing numerous acoustic transducers under the ship. Then, for each transducer, we are calibrating the old acoustic system and the new acoustic system.

All smiles at the end of calibration as we head out to continue our mission at sea:-) In this photo: NOAA TAS Justin Garritt, Scientist Volunteer Heather Rippman, and Future Scientist Charlie Donahue (and roommate)

______________________________________________________________________________________

A Tour of the ship

NOAA Ship Bell M. Shimada is an incredible vessel that sails for months at a time. It has a crew of over 40 people (who I will be discussing in future blogs). The ship is a science lab with most state of the art equipment and also home for the crew on board that make the boat run 24 hours a day for 365 days a year. Here is a quick behind the scenes look at this remarkable vessel.

The Deck: When you embark the ship, the first thing you see is a huge deck with massive pieces of equipment. Each item has a different purpose based on what scientific study is taking place throughout the leg of the journey.

Two of the nets we will be using to catch hake and other organisms. Each net has different size liners which we will be testing.

A view of the back deck and all the equipment

Another view of the back deck

A view looking up from the deck at the top vessel

The Bridge: This is where the captain and his crew spend most of their day. The bridge has all of the most up-to-date technology to ensure we are all safe while on board. Operations occur 24 hours a day, so the ship never sleeps. Officers on the bridge must know what is happening on the ship, what the weather and traffic is like around the ship. The bridge has highly advanced radar to spot obstacles and other vessels. It also is the center of communication for all units on board the ship.

The officers of NOAA Ship Bell M. Shimada.

The bridge of NOAA Ship Bell M. Shimada

The Galley and Mess Hall: I expected to come on board and lose weight. Then I met Arnold. He is our incredible galley master who makes some of the best meals I have had on a ship. Yes, this better than food on a buffet line on a cruise. Arnold works his magic in a small kitchen and has to plan, order, and organize food two weeks out. Breakfast, lunch, and dinner are all served at the same time everyday. The food is prepared and everyone eats in the mess hall. Beverages, cereal, salad, and most importantly, ice cream are available 24 hours a day, so there is no need to ever be hungry. Every meal has a large menu posted on the television monitor and you can eat whatever you want. Every meal so far has been amazing.

Master Chef Arnold showing me his organized refrigerator

In the food storage closet

The mess hall

An amazing buffet is served three times a day at 7am, 11am, and 5pm.

The menu is posted for every meal

Salad is available 24 hours a day

Ice cream and snacks available 24 hours a day

Drinks are always available

Staterooms: Sleeping quarters are called staterooms and most commonly sleep two people. Each stateroom has its own television and a bathroom, which is called a head. As The bunks have these neat curtains that keep out the light just in case you and your roommate are working different shifts.

My stateroom which I share with Charlie, a volunteer college student

Names on our door

Laundry Room: There are three washer machines and three dryers that crew can use to clean their clothes during off-duty hours

The laundry room

The Entertainment Room: The living room of the ship. This room has a large screen TV, comfy recliners, and hundreds of movies, including new releases.

The gym

The entertainment room

The Acoustics Lab: The acoustics lab is like the situation room for the scientists. There are large computer screens every where that can monitor all of the things the scientists are doing. For the past two days, Rebecca, our Chief Scientist, along with other scientists, lead the calibration from that room.

Scientist Steve de Blois hard at work in the acoustics lab

Scientist Dezhang Chu hard at work in the acoustics lab

A look at the entire acoustics lab

The Wet Lab: The wet lab will be used to inspect and survey the hake when we start fishing later this week.

The wet lab which will be used when we start fishing later this week

A random look in the freezer in the wet lab:-)

I only just began my exploration of the ship. I will have so many more places to share throughout the journey. Later this week I will be asking our Chief Engineer to take me on a behind the scenes tour of “below deck” which is where they turn salt water to freshwater, handle all trash on board, etc. I will also be asking a member of captain’s officers to teach me a little about the navigation equipment up in the bridge. I will be sure to write about all I learn in future blogs.

Thank you for continuing to join me on this epic adventure.

Justin

Calibrating with the Seattle skyline in the distance

An early morning sunset workout on the bow

June 11, 2018

Lacee Sherman: Teacher Getting Her Sea Legs! June 8, 2018

NOAA Teacher at Sea

Lacee Sherman

Aboard NOAA Ship Oscar Dyson

June 6, 2018 – June 28, 2018

Mission: Eastern Bering Sea Pollock Acoustic Trawl Survey

Geographic Area of Cruise: Eastern Bering Sea

Date: June 8, 2018

Weather Data from the Bridge on 6/9/18 at 17:00

Latitude: 55° 34.3 N

Longitude: 162° 39.0 W

Sea Wave Height: 2-3 ft

Wind Speed: 12 knots

Wind Direction: 335° NW

Visibility: 8 knots

Air Temperature: 7.1° C

Water Temperature: 8.6° C

Sky: Blue with scattered clouds

What have you done to protect the oceans lately? Picture of Lacee with finger pointing at camera — World Oceans Day! June 8th, 2018. What have YOU done to protect the oceans today?

Science and Technology Log

On Wednesday, June 6th 2018, NOAA Ship Oscar Dyson left port from Dutch Harbor Alaska at 08:00 to go and fuel up for the upcoming voyage. Fueling the ship takes hours and during that time, NOAA Ship Oscar Dyson took on over 50,000 gallons of fuel. After the ship was fueled, it searched for a spot in Captain’s Bay to calibrate the acoustic equipment. In order to calibrate the equipment, a metal ball made of tungsten carbide was suspended beneath the boat under the center board. The ball has known acoustic return values based on density and purity of the metal. It is attached at three points to the boat so that it can be moved under the center board to calibrate each transducer.. The location of the ball is adjusted under each transducer one at a time to the center of each beam. Adjustments to the equipment will be made if the return from the ball at each transducer is not as it is expected to be. The scientists had to change the depth of the ball in the water in order to avoid the fish to get an accurate reading. The calibration can be different depending on the temperature of the water and the salinity (saltiness) of the ocean. A second calibration will be taken at the end of the research cruise and the average will be used in the necessary calculations. Once calibration was complete and the equipment was retrieved, the ship started heading to the beginning location of the first transect line.

The journey from our calibration point to the start of the first transect line took approximately 23 hours, traveling at 12-13 knots. The ship reached the northern end of the first transect line at approximately 21:00 (9 pm) on June 7th. The first trawl sample was taken shortly after at sunset, which was approximately 23:30 (11:30 pm). This is not an ideal time to collect a trawl sample though since the fish move and behave differently at night. The first trawl sample of the survey that I participated in was on 6/8/18 at approximately 15:30.

Operations on the ship run 24 hours a day, so some members of each team onboard need to be awake and working at all times. Shifts for the science team are 12 hours long and the day shift runs from 04:00 (4 am) to 16:00 (4 pm) and the night shift is from 16:00 (4 pm) to 04:00 (4 am). I am assigned to the day shift along with Chief Scientist Denise McKelvey and Fisheries Biologists Sarah Stienessen, Mike Levine, and Scott Furnish. On the night shift for the science team are Nate Lauffenburger, Darin Jones and Matthew Phillips.

Scientists

NOAA Corps Officers

Deck Crew

ET, Stewards, Survey Techs

Engineers

In order to collect a trawl sample, members of basically every department on the ship are involved. The NOAA Corps officers are on the Bridge driving the ship, charting the course that the ship will be traveling on as it collects it’s samples, as well as keeping track of the net, and all of the other duties that they regularly hold. The stewards keep us all fed and happy. The deck crew are in charge of making sure that all of the nets are hooked up properly and are put into the water correctly as well as controlling the winches that release the nets. The engineers make sure that all equipment is functioning properly. The survey technicians ensure that all of the scientific instruments used for making any type of measurements are attached to the net at different points, mainly on the kite. The “kite” is a section of the net primarily used for holding scientific instruments. Some of the scientists are preparing the fish lab and getting dressed in waterproof gear, while the Chief Scientist is on the Bridge with the officers giving direction about where and when to start and stop trawling and exactly how deep the nets should be set. Adjustments to the net are regularly made during the sample collection.

Waterproof gear hanging in the “ready room”.

Gloves hanging to dry in the fish lab.

The locations for when trawl samples will be collected is not pre-determined before the start of the research cruise. The sites for samples are determined in real time by looking at the data collected from the acoustic pings being sent out by the transducers. There are 5 different frequencies( measured in kilohertz) sent out by the ship’s transducers: 18 kHz, 38kHz, 70 kHz, 120 kHz, and 200 kHz. The acoustic frequency that may best indicate the presence of pollock is 38 kHz. The chief scientist decides when she wants to “go fishing” based off of looking at the results coming back as echoes to the ship.

Acoustic data points collected at 5 wavelengths — This is what the acoustic data points look like as the ship is moving on the water. All 5 different frequencies are depicted in this image. The top left is 18kHz, bottom left is 38kHz (best for pollock), top right is 70kHz, middle right is 120kHz and the bottom right is 200kHz. Each dot represents an echo received by the ship’s transducers after the sound hits something in the water. The solid red band near the top of each window is the depth of the sonar transducer sending the acoustic pings, while the heavier red band at the bottom of each window is the sea floor.

On this leg of the research cruise thus far, 3 trawl samples have been collected from the transect lines. I will include more detailed information and photos of the fish processing protocol in my next blog. In the next three pictures, there are temperature and depth profiles of our sample collection. The depth (in meters) is shown by the shape of the line as it rises and falls, and the color shows the temperature (in degrees Celsius) that goes with the scale on the right of each figure. More specific details are underneath each image.

Personal Log

Now that the ship is in the middle of the Bering Sea and is moving, I have learned an important lesson: You can’t trust the floor. I know that sounds weird, but usually you know exactly where the floor is going to be when you are walking, but when the ship is moving in the water, the floor may be higher or lower than expected, causing a lot of wobbling. This is especially challenging for someone who is as naturally clumsy as I am. There are times when I feel like a toddler learning to walk again, but I am getting more and more used to it already. At night it feels like being gently rocked to sleep.

I’m learning my way around the ship and I am starting to not walk right past the doors that I need to go into a few times before I remember that it’s the right place. I am also getting more familiar with the people onboard as well as the schedule. Since my shift that I am working on is from 04:00 (4 am) to 16:00 (4 pm), it took a few days for me to adjust and everyone was very patient with me. Coffee definitely helps! The meal times are as follows: Breakfast 07:00, Lunch 11:00, Dinner 17:00 and there are always some snacks available in the Galley.

Ocean Selfie! 6/7/18 — Photo of TAS Lacee Sherman aboard NOAA Ship Oscar Dyson in the Eastern Bering Sea.

In my downtime on the ship, I have found a new favorite location; the flying bridge! The flying bridge is located above the Bridge (where the Ship is controlled). There is a chair up there that makes the perfect spot on a nice day to sit and read for a little while. It is windy and cold, but worth it! The view from up there is pretty amazing!

Image taken off of the Alaskan Peninsula taken from the Flying Bridge on 6/9/18 in the morning.

Image taken off of the Alaskan Peninsula taken from the Flying Bridge on 6/9/18 in the afternoon from a closer location.

The bow of NOAA Ship Oscar Dyson taken from the Flying Bridge.

The Stern of NOAA Ship Oscar Dyson taken from the Flying Bridge.

Did You Know?

The NOAA Commissioned Officer Corps is one of the 7 uniformed services in the United States. The other 6 include: Army, Marine Corps, Navy, Airforce, Coast Guard, and the Public Health Service Commissioned Corps.

Math Challenges!!!!

If the Dyson regularly travels at 12.5 knots, how many miles per hour is it going? (Hint: you may want to look at my previous blog before you try this.)

Currently 9 of the people aboard the NOAA Ship Oscar Dyson are women. If there are 31 total people on the ship, what percentage of them are women?

July 29, 2017August 15, 2017

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: 22^o45’N, 157^o56’W. Ship speed: 1.3 knots. Air temperature: 27.8^oC. Sea temperature: 27.0^oC. 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.

blog.4.Day6.image1 — 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”.

blog.4.Day6.image2 — 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.

blog.4.Day6.image3 — 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.

blog.4.Day6.image4 — 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:

blog.4.Day6.image5 — 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.

June 15, 2017

Chris Murdock: Calibration Time! June 9, 2017

NOAA Teacher at Sea

Chris Murdock

Aboard NOAA Ship Oregon II

June 7 – June 20, 2017

Mission: SEAMAP Groundfish Survey

Geographic Area of Cruise: Gulf of Mexico

Date: June 9, 2017

Weather Data from the Bridge

Latitude: 27.193 N
Longitude: 93.133 W
Water Temperature: 28.8 C
Wind Speed: 10.5 knots
Wind Direction: 92.59 degrees
Visibility: 10nm
Air Temperature: 25.9 C
Barometric Pressure: 1012.6 mbar
Sky: Clear

Science and Technology Log

Prior to our departure from Pascagoula, the ship anchored approximately 8 miles off the coast in order to run a calibration test. This is done in order to calibrate the ship’s multi-beam echosounders. Echosounders emit sound waves downward towards the ocean floor that measure and record the time it takes an acoustic wave signal to travel to the ocean floor, bounce off, and return back to the receiver. Think of this like a dolphin’s echolocation. Dolphins emit sound waves that bounce off objects and allow the dolphin to determine the distance that object is. As you can imagine, this is incredibly important!

How an echosounder works Source: noaa.gov

IMG_4317[1] — The *Oregon II* echosounders

The entire calibration process takes a long time, and that time drastically varies depending on the amount of sensors a ship has. The Oregon II has two echosounders, so this whole process took roughly 6-8 hours. The calibration process works like this: Calibration requires deploying one or more calibration spheres under the ship. These are lowered into deep waters, or in wave terms the farfield (the outer limits of the sensors). Each sensor is tethered to a series of down-riggers mounted on the upper deck of the ship, on both the starboard (right) and port (left) sides of the ship. This essentially centers the sphere allowing the operator to control where under the boat the calibration sphere is. The controllers of the down-riggers move the spheres in specific locations until the sensor on deck is fully calibrated.

IMG_4131[1] — Diagram of calibration set up (Noaa.gov)

Calibration sphere (Noaa.gov)

Downrigger system (Noaa.gov)

The calibration of the echosounders is vital to the success of this study, as well as studies like hydrography. Knowing the proper depth of the ocean underneath the ship is used to determine when and where to trawl for stock assessment (which I will talk about in later blog posts!)

Personal Log

So far, life aboard the Oregon II has been smooth sailing (pun intended). We finished the sensor calibration on Wednesday, and have spent the past two days traveling to our first sampling location, so I have had sufficient time to become acclimated to the way things work out in open waters. Thankfully, I am used to being on a rocking ship, so I don’t foresee seasickness being an issue (fingers crossed). I have gotten to know most of the crew, as well as all of the other volunteers aboard the ship. Most of the volunteers/interns are graduate students from schools scattered around the south. I look forward to sitting down with each of them to learn more about their specific fields of study and why they chose marine science.

It has been nice to have this downtime, because it has allowed me to become familiar with how things work on board. With the calibration and travel time, I have really fallen in love with being out on the open water. I spent most of my time on the flying bridge of the Oregon II, or as many of the crew call it the “steel beach”. There is a plethora of workout equipment up there, as well as chairs to have a cup of coffee between shifts. Exercising on the top of a rocking boat is not easy! I have come to find it quite peaceful, however. There is something about being able to look out at the vastness of the open water, with only the occasional speckling of oil rigs and tankers off in the distance, that allows you to separate yourself from everything else and be in that moment. Sometimes, I even spot large numbers of flying fish leap from the boat’s wake and travel just above the surface of the water for large distances, only to watch them disappear into the blue void. For a Midwestern kid, they are truly fascinating animals.

IMG_4232[1] — Stairs from the bottom deck up to the crew’s lounge

IMG_4095[1] — TAS Chris Murdock wearing helmet and life jacket

Yesterday was also the time for our first series of drills. We conducted a fire safety drill, as well as the all-important abandon ship drill. In the later, we don our survival suits and life jackets and head to muster (gather) at the bow of the ship (remembering the directions and other ship lingo is taking a little bit to get used to, but after the first day or so it has just become second nature. Port is left, starboard is right, the bow is the front, and the stern is the back). You then have two minutes to properly put it on. The suit itself looks and feels like a giant red Gumby costume, but immediately you can see the benefit of it. It completely surrounds your body with watertight neoprene, and has specially located lights and floats to keep you insulated and on the surface of the water. While you may think the Gulf is very warm (it is), the temperature is roughly 86 degrees Fahrenheit, which is about 12 degrees colder than your core body temperature. In the event that you would have to abandon ship that 12 degree difference would eventually take its toll on you and you could become hypothermic. We do drills like this on a weekly basis to keep our skills sharp. Hopefully we never need them!

FBNH3430[1] — A view like this never gets old

In just a few hours I will begin my first shift on deck collecting data for a stock assessment. I am both excited and nervous. Nervous in the sense of not knowing what to expect, but I cannot wait to get started. While I have loved the downtime to learn the ways of the ship and get to know the crew, I know that it will not last. This type of work is going to be very new to me, and the hours very long. While it is most certainly intimidating, I cannot wait to begin this very important scientific work.

Did You Know?

The deepest part of the Gulf of Mexico is an area known as the Sigsbee Deep. At its deepest, it is more than 12,000 feet! At more than 300 miles long, it is commonly referred to as the “Grand Canyon under the sea”. (Source-Encyclopedia Britannica)

August 9, 2013March 12, 2021

Julia Harvey: Calibration in Sea-Otterless Sea Otter Bay, August 7, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013

Mission: Walleye Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Date: 8/7/13

Weather Data from the Bridge (as of 21:00 Alaska Time):
Wind Speed: 10.42 knots
Temperature: 13.6 C
Humidity: 83%
Barometric Pressure: 1012.4 mb

Current Weather: A high pressure system is building in the east and the swells will increase to 8 ft tonight.

Science and Technology Log:

Before I begin, I must thank Paul for educating me on the calibration process. Because calibration occurred during the day shift, I was not awake for some of it.

The EK60 is a critical instrument for the pollock survey. The calculations from the acoustic backscatter are what determines when and where the scientists will fish. Also these measurements of backscatter are what are used, along with the estimates of size and species composition from the trawling, to estimate fish biomass in this survey. If the instruments are not calibrated then the data collected would possibly be unreliable.

Calibration of the transducers is done twice during the summer survey. It was done before leg one in June, which began out of Dutch Harbor, and again now near Yakutat as we end leg three and wrap up the 2013 survey.

As we entered Monti Bay last night, Paul observed lots of fish in the echosounder. This could pose a problem during calibrations. The backscatter from the fish would interfere with the returns from the spheres. Fortunately fish tend to migrate lower in the water column during the day when calibrations were scheduled.

This morning the Oscar Dyson moved from Monti Bay, where we stopped last night, into Sea Otter Bay and anchored up. The boat needs to be as still as possible for the calibrations to be successful.

Monti and Sea Otter Bays Map by GoogleEarth — Monti and Sea Otter Bays
Map by GoogleEarth

Calibration involves using small metal spheres made either of copper or tungsten carbide.

Chief Scientist Patrick Ressler with a tungsten carbide sphere

Copper sphere photo courtesy Richard Chewning (TAS) — Copper sphere
photo courtesy Richard Chewning (TAS)

The spheres are placed in the water under transducers. The sphere is attached to the boat in three places so that the sphere can be adjusted for depth and location. The sphere is moved throughout the beam area and pings are reflected. This backscatter (return) is recorded. The scientists know what the strength of the echo should be for this known metal. If there is a significant difference, then data will need to be processed for this difference.

The 38 khz transducer is the important one for identifying pollock. A tungsten carbide sphere was used for its calibration. Below shows the backscatter during calibration, an excellent backscatter plot.

The return for this sphere was expected to be -42.2 decibels at the temperature, salinity and depth of the calibration The actual return was -42.6 decibels. This was good news for the scientists. This difference was deemed to be insignificant.

Personal Log:

Calibration took all of the day and we finally departed at 4:30 pm. The views were breathtaking. My camera doesn’t do it justice. Paul and Darin got some truly magnificent shots.

As we left Yakutat Bay, I finally saw a handful of sea otters. They were never close enough for a good shot. They would also dive when we would get close. As we were leaving, we were able to approach Hubbard Glacier, another breathtaking sight. Despite the chill in the air, we stayed on top getting picture after picture. I think hundreds of photos were snapped this evening.

Location of Hubbard Glacier. Map from brentonwhite.com

Many came out in the cool air to check out Hubbard Glacier

Lots of ice from the glacier as we neared

Nearby Hubbard Glacier with no snow or ice — Near Hubbard Glacier

Did You Know?

According to the National Park Service, Hubbard Glacier is the largest tidewater glacier in North America. At the terminal face it is 600 feet tall. This terminal face that we saw was about 450 years old. Amazing!

Staci DeSchryver: Don’t Hate, Just Calibrate! August 9, 2011

NOAA Teacher at Sea
Staci DeSchryver
Onboard NOAA Ship Oscar Dyson
July 26 – August 12, 2011

Mission: Pollock Survey
Geographical Area of Cruise: Gulf of Alaska
Location: Barnabas Strait 57 deg 22.630 N, 152 deg 24.910W
Heading: 67.8 deg
Date: August 9, 2011

Weather Data From the Bridge
Partly Cloudy Skies
Temp: 13.5 deg
Dewpoint: 6 deg
Barometric Pressure: 1020 mb, falling, then steady
Wind: 240 deg at 12kts
Seas: Calm
stn model 08.11

Science and Technology Log

The start of my first official shift onboard the Oscar Dyson was an interesting one! We had lost some time (11 days) to some complications, so our cruise goals shifted a bit from the original plan. We had to focus on the most important aspects of the mission, and sacrifice carefully, as it wasn’t plausible to complete the entire mission in the time allotted. One of the major steps for completing the season was to do what is known as a calibration. In order to save time, we did the calibration on my first night out on the job!

Calibrations are typically done during the daytime because the fish are curious little beasts. During the day, they move lower in the water column, and therefore do not interfere with the calibration of the system, mainly because they are so far away they are oblivious to it. At night, however, they party at a shallower depth, and sometimes their acoustic signatures can mar the data collected during a calibration. It is critical to the scientists that they calibrate the acoustic system accurately, and if there is a school of fish swarming the calibration tools, well, it’s a big ‘ole mess. Given that we are on a shortened time schedule, it made practical sense to conduct the calibration overnight.

Marshmallow has been very helpful on the trip. Here he is counting krill. I don't have the heart to inform him that these krill have already been counted.

Why do we calibrate the acoustic transducer? Think of it like this. Have you ever baked cookies before and followed the directions to the letter, only to have them come out of the oven like crispy critters or balls of goo? Or, let’s say, you have a favorite recipe you use all the time, and you gave the recipe to a friend who makes the same cookies the same way, yet complains that they are overcooked? Well, one of the reasons that the recipe may have not turned out was because either your oven, or your friend’s oven was not properly calibrated. Let’s say, for example, the recipe calls to bake the cookies at 350 degrees for 15 minutes.

If you turn the dial to 350 degrees, it is reasonable to expect that the oven is, in fact, 350 degrees. But there is an equal possibility that the oven is actually only 325, or maybe even 400 degrees. How would you double check to see if your instrument is off its mark? One solution is to heat the oven to 350, and use a meat or candy thermometer that you know has an accurate readout and then put the thermometer in the oven. If the candy thermometer reads out at 350, you can be certain that your oven really is 350 when you turn it on. If the candy thermometer reads out at 375, then you can be certain there’s an error in the readout of your instrument. Calibration corrects for those errors.

Here you see Cat and I showing off the downrigger - the piece of equipment that holds the calibration spheres under the ship.

Calibration on this survey is important because scientists use information from the acoustic transducer to determine the types and abundance of organisms in the water column. If the instrument they use to make these predictions is off in any way, then all of the data they collect could be determined to be insufficient or unreliable. Calibration also ensures that acoustic measurements (and survey results) are comparable between different cruises, locations, and times.

Calibration is done much in the same way as an oven is calibrated. We take an object that has a known and reliable return rate on the acoustic transducer, and hang it below the ship. Then, the scientists will “ping” acoustic soundings off of the object and see how well the return matches up with the known return rate. If it’s off, then they can “tune” the transducers, much like a guitar is tuned.

downriggers ii — Here, the chief scientist, Chris Wilson, double checks our superior downrigging work!

It is only necessary to calibrate the transducers twice per survey – once at the beginning of the survey (one was done in June) and one at the end of the survey (which was now). When the transducer is calibrating, the ship must be as close to stationary as possible. This is why the lead scientist chose to do the calibration at night – we can’t calibrate and conduct assessment surveys at the same time. Therefore, it’s a one-pony show when the transducer is calibrating. Almost all other scientific field work ceases while the calibration is completed.

There are two materials used for calibration for this particular transducer on the Oscar Dyson. The first is Tungsten Carbide, and the second is pure Copper. These small, spherical objects are quite cleverly hung below the ship off of three downriggers attached to the port and starboard rails. In order to hang the spheres, the strings on either side of the ship must connect. In a sense, we ask the Dyson to “jump rope” to get the calibration sphere underneath the ship in the correct position.

Calibration takes about six to eight hours to complete. I got to help with setting the downriggers up, changing out the calibration spheres, and breaking down the equipment. As it turns out, the transducer only needed minor adjustments this time, which is pretty typical for the ship. However, it’s important to double check so that if there is a problem, it can be detected early and corrected.

Personal Log

Today, the chief engineer of the ship, Jeff, gave us a tour of the engine room. Holy cow, was that impressive! I don’t know what I was thinking when I thought that the guts of this beast were contained in one small room. They most decidedly are not. There are two whole decks below the lowest level I know of – and they are filled with all kinds of interesting equipment. We got to see all of the engines (there are 4 diesel generators), where the water is purified for consumption, and all of the internal components of the winch system that lowers and raises our fishing nets. As if that weren’t enough, we popped open a floor hatch, climbed down the ladder two flights, and got to stand right on the “skin” of the boat. Translation: The only thing separating my feet and the big blue sea was a thin little piece of metal. It was so cool. The ship is designed to be “acoustically silent” – like a stealth fighter, except they don’t call it stealth and we aren’t fighting enemies – we are hunting fish. Because of this, many of the larger pieces of equipment are hoisted up on platforms that silence their working parts. The ship has diesel-electric propulsion.

engine rm — Here is just ONE of the four massive engines on the ship!

This means that there are four diesel generators that make electricity, which then gets split into two different forms – one type is for propulsion, and the other is for our lights and other conveniences. It sounds really complicated, and much of what the engineers do on board is quite complicated, but everything onboard is smartly labeled to help the engineers get the job done. I also learned today what the funny numbers on all of the passage doors mean. See the caption for a description.

Here is one of the door signs on the ship, which act like a "you are here" sign on a map. The first number tells us what floor we are on. The second number tells us what area of the ship we are in. The third number tells us whether we are port, starboard, or in the center of the ship.

One thing that Cat and I were discussing this morning while searching through binoculars in Alitak Bay for interesting woodland creatures was that we can go pretty much wherever we want to go on this ship. Everyone who works and lives here is so friendly and welcoming. They answer any of our questions (even the silly ones) and they all have such cool life stories. What’s better is that everyone is willing to share what they’ve learned, experiences they’ve had, and accomplishments they’ve achieved to make it here. I am aboard a utopian city bursting with genuine people who love what they do. Now, please understand that it’s not that I ever expected the opposite for even a single second. The science and technology is definitely neat, but the people who live and work here are what is making this trip a once-in-a-lifetime experience.

Do you know….

Your Ship Superstitions?

1. Bananas on a boat are considered bad luck.

2. Black luggage for sailors is considered bad luck.

3. One should never whistle – especially on the bridge or in the wheelhouse – you may whistle up a storm.

4. To see a black cat before boarding is good luck.

5. Dolphins swimming along the ship are good luck.

6. Never sail on Friday – it’s unlucky.

7. Never sail on the first Monday in April – also unlucky.

8. Never say the word “Drown” on a ship, as it encourages the act.

9. Sailors should avoid flat-footed people – they are bad luck.

10. Never step onboard a ship with your left foot first.

June 24, 2006March 19, 2021

Diana Griffiths, June 24, 2006

NOAA Teacher at Sea
Diana Griffiths
Onboard UNOLS Ship Roger Revelle
June 22 – June 30, 2006

Mission: Hawaiian Ocean Timeseries (WHOTS)
Geographical Area: Hawaiian Pacific
Date: June 24, 2006

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.

June 22, 2006March 19, 2021

Diana Griffiths, June 22, 2006

NOAA Teacher at Sea
Diana Griffiths
Onboard UNOLS Ship Roger Revelle
June 22 – June 30, 2006

Mission: Hawaiian Ocean Timeseries (WHOTS)
Geographical Area: Hawaiian Pacific
Date: June 22, 2006

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. — 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.

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 19^th, 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.