seawater sample – NOAA Teacher at Sea Blog

July 30, 2009April 5, 2021

Robert Oddo, July 30, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown
July 11 – August 10, 2009

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 30, 2009

Weather Data from the Bridge
Outside Temperature 25.50^oC
Relative Humidity 87%
Sea Surface Temperature 25.75^oC
Barometric Pressure 1017.3 inches
Latitude 20 09.721 N Longitude 33 34.806 W

Science and Technology Log

On the 28^thof July we did our 34^thCTD and changed out our third buoy and started to steam west back towards the states. We have a break now from our 12-hour shifts and only have one more buoy to change out and only one more CTD to deploy. I wanted to write about a couple of things that I have noticed over the last couple weeks when sampling that I thought were noteworthy. The seawater we collect from 1500 feet down in the ocean, even though we are in the tropics, is still very cold. It is about 4 degrees C or 39 degrees F while the sea surface temperature is around 26 degrees C or 79 degrees F.

Another thing that is really cool is that when we are doing CTDs at night the lights from the ship attract squid and you can watch the squid chasing flying fish at the surface. The last thing that is strange, is that every once in a while even though we are hundreds of miles away from land, a butterfly or dragonfly darts around the ship. You just wonder where they have come from. Every night around 8 pm, there is meeting of all the scientists onboard. We usually get a weather briefing and then someone will give a seminar on the work they are doing. There are many links between the work that each scientist is doing on this ship and this is an important way to share ideas, get feedback and create new questions.

Personal Log

There is down time on the ship and I wrote about the movies earlier. We have a ping-pong table set up in the main lab where we play in our spare time. Since we are so far from any land, safety is very important on the ship. We have fire drills and abandon ship drills weekly. After the drill there is a briefing and the safety officer discusses some of the safety equipment the ship has and its use. Today we went out to the fantail and the officers demonstrated how to use flares and smoke signals.

A little ping pong in the main lab (left) and flare demonstration (right)

July 25, 2009April 5, 2021

Robert Oddo, July 25, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown
July 11 – August 10, 2009

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 25, 2009

Weather Data from the Bridge
Outside Temperature 26.94^oC
Relative Humidity 81.85%
Sea Temperature 27.84^oC
Barometric Pressure 1013.74 inches
Latitude 13^o 07.114N Longitude 23^o 00.000W

Science and Technology Log

I have continued to help out on the 11:30 am to 11:30 pm watch with CTDs and XBTs. Why do so many CTDs and XBTs? The scientists on board are developing a subsurface profile of the water temperature, salinity and density. Based on these data, models can be constructed and refined that can help us better understand what is happening in the Tropical Atlantic.

Removal of radiometer and anemometer from buoy

The Brown arrived at the second buoy that needed to be serviced on July 24^th. I was lucky enough to get on the small boat sent out to take some equipment off the buoy before it was pulled up on the boat. Once at the buoy, the radiometer and the anemometer were removed. An acoustic message is then sent from the Brown to release the anchor on the buoy. The buoy is then attached to a rope from the Brown and pulled up onto the fantail. All the instrumentation and sensors below the buoy are pulled up on the Brown and exchanged. I attached a picture of the buoy to the right so you get an idea of all the instrumentation that is attached to these buoys. I could not believe all the fish that were around the buoy. Apparently, the buoy creates a small ecosystem, where all kinds of marine organism congregate. Algae and small crustaceans attach to the buoy and some of the cables that are underneath. Small fish eat the algae and crustaceans, larger fish eat the smaller fish and before you know it you have a food web. Some of the fish are huge. Yellow fin tuna, triggerfish and mahi mahi. This actually causes a big problem. Fishermen come out to these buoys and damage the buoy instrumentation when they are fishing and we end up losing valuable data.

This figure shows all the instrumentation attached to the buoy.

Personal Log

Once the buoy is pulled up onto the ship, the fish that were around it looked for a place to go. Sometimes they come under the ship. We threw a few fishing lines in after the buoy was pulled up on the fantail and the tuna were biting like crazy. We caught a few that afternoon and had them for lunch the next day!!

July 23, 2009April 5, 2021

Robert Oddo, July 23, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown
July 11 – August 10, 2009

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 23, 2009

Weather Data from the Bridge
Outside Temperature 26.77^oC
Relative Humidity 74.89%
Sea Temperature 27.64 ^oC
Barometric Pressure 1013.98 inches
Latitude 07^o 59.993 N Longitude 22^o 59.767W

Science and Technology Log

We arrived at the first buoy two days ago and exchanged the “package” which is kind of like the brains of the buoy. Four people went out with a small boat and exchanged the package. This is not an easy task since you have to climb off the small boat onto the buoy in what can be pretty rough seas and change instruments. We also deployed the “CTD” for the first time. After the deployment, we collected seawater from various depths for salinity and dissolved oxygen analysis. We also are deploying XBTs every 10 nautical miles on a 24 hours schedule as the ship steams along its course. There are two shifts. I am on the 12 noon to 12 midnight shift. The XBT (Expendable Bathythermograph) is dropped from a ship and measures the temperature as it falls through the water. Two very small wires transmit the temperature data to the ship. When it gets to about 1500 meters, the small wire is cut and the operation is over. By plotting temperature as a function of depth, the scientists can get a picture of the temperature profile of the ocean at a particular place.

Preparing to service a buoy (left) and recovered buoy on deck (right)

Yesterday, we got to the second buoy and had to pretty much exchange it with a new package, sensors and an anchor. This took over 8 hours to do and takes a lot of manpower. The buoy is actually pulled up on the deck as well as the instrumentation below the buoy and then new instruments, buoy and an anchor are deployed. If this is not done exactly right, everything can be destroyed.

Personal Log

Wow, there is a lot of action right now on the ship. The atmospheric scientists are releasing sondes, collecting dust and smoke samples, and measuring incoming solar radiation at different wavelengths. There are people getting instrumentation ready for the next buoys we are steaming towards. People are deploying CTDs, XBTs, and drifters. Behinds the scenes the crew lends all kinds of support, from preparing food, working the winches and cranes, navigating through the ocean and working in the engine room It is really teamwork that makes this all work and not any one person could do all of this work. There are a lot of very dedicated people onboard this ship and all their hard work make this work!!

Here I am deploying an XBT (left) and collecting seawater samples from the CTD (right)

May 20, 2009April 5, 2021

Robert Oddo, July 15-20, 2009

NOAA Teacher at Sea
Robert Oddo
Onboard NOAA Ship Ronald H. Brown
July 11 – August 10, 2009

Mission: PIRATA (Prediction and Research Moored Array in the Atlantic)
Geographical area of cruise: Tropical Atlantic
Date: July 15-20, 2009

Weather Data from the Bridge
Outside Temperature 24.19 ^oC
Relative Humidity 78.87
Sea Temperature 24.28 ^oC
Barometric Pressure 1016.0 inches
Latitude 00^o 12.5 N Longitude 23^o 37.28W

Science and Technology Log

We have been steaming at around 10 knots(approx 11.5 mph) 24 hours a day to our first buoy. The scientists on board are preparing equipment for the work that awaits them once we arrive at our first stop, 0 degrees 01.0 South latitude, 22 degrees 59.9 West. Replacement tubes for the buoys are being readied and the “CTD” is being prepared for deployment. The “CTD” is the name for a package of instruments that is lowered in the water that includes sensors that measure conductivity, temperature and the depth of the seawater. Conductivity and temperature are important since salinity can be derived from these values. The CTD is connected to the ship by means of a cable through which real-time data can be sent back to scientists on the ship as the winch lowers and raises the CTD through the water. The metal frame around the CTD has a number of bottles attached to it that collect seawater samples at various depths. This water then can be analyzed back in the laboratory when the CTD is brought back on board.

We have deployed a number of drifters as we are making our way to the first stop. For the last couple of days, we have not been allowed to collect any data as we traveled through the territorial waters of Brazil. On the night of July 19^th we launched an ozonesonde. An ozonesonde transmits information to a ground receiving station information on ozone and standard meteorological quantities such as pressure, temperature and humidity. The balloon ascends to altitudes of about 115,000 feet (35 km) before it bursts.

Personal Log

A few days ago, I toured the bridge of the ship. There is always one officer on the bridge and also a person on watch. Unfortunately there is not a big wheel like I imagined up there to steer the ship (I always wanted my picture at one of those big wheels). But there are a number of thrusters that you maneuver the ship with. There are also a number of radar screens that enable one to see surrounding objects and well as computers that allow the ship to run on different auto pilot modes. Before a radiosonde or a buoy is launched, one needs to inform the bridge and the operation is logged in. You really get a unique perspective of the ship from up on the bridge.

I have spent hours on deck watching for signs of life out in the ocean. We did have a pod of dolphins of our bow one day, flying fish seem to be out there all the time and one day we believe we saw a pod of false killer whales (maybe). I expected to see some birds, but so far not one.