Irminger Sea Cruise Blog: First Days at Sea!

(by Emma)

Our team and the R/V Neil Armstrong have officially left the Reykjavik port.

After we left the harbor waters, the underway sea system started pumping and we began to collect continuous data from the oxygen and nitrate sensor we set up earlier. Lucy and I also practiced collecting chlorophyll, dissolved inorganic carbon, and dissolved oxygen samples on the underway system.

Photo of the Reykjavik Opera House taken from the ship deck: a 5-6 floor-tall pair of connected but asymmetric buildings covered completely with glass windows. The glass windows form hexagonal cells which jut out from the sides of the building, creating a beehive-like texture. The different angles of the outer glass panes make each window look a slightly different color, such as gray, blue, purple, and green.

While leaving the harbor, we had a great view of Harpa, a concert hall in Reykjavik, from deck. Lucy and I walked around Harpa on Sunday evening before the Armstrong moved to the warehouse dock on Monday.

I really enjoy the different types of bottles and measuring instruments we brought to collect samples; the distinct look and feel of each bottle helps me remember which sampling procedure to use. Dissolved oxygen samples are the most common samples that Lucy and I will be taking throughout the trip. For the dissolved oxygen sampling, everything happens in one glass bottle with a distinct, labeled stopper. The bottle is rinsed and filled with seawater from either the underway system or the Niskin flask from a CTD (conductivity, temperature, depth) cast. We then add MnCl₂ and NaI-NaOH as fixing reagents to capture the dissolved oxygen in the sample into a substance that looks like spoiled orange juice in the bottom of the bottle. After rigorous shaking, we store the samples, shake them again later, and Hilary analyzes each bottle using the Winkler Titration Method set up on our lab bench.

Photo of a smiling young woman standing on the right of the photo, with an equipment set up featuring a rosette and CTD to the left. The equipment stands about 5-6 feet tall, and has 3 metal bands which are about 2 inches wide around a central metal pole. Around the pole, contained within the metal bands, are gray cylindrical flasks arranged vertically and labeled with numbers (the rosette). Below the flasks, there are a series of metal and plastic tubes attached to black sensor boxes (the CTD and other sensors). Also visible is an orange box attached to the lowest metal band. The girl and equipment are on the deck of a vessel, with the ship railing and a small amount of seaside port visible in the background.

This is Lucy standing next to the CTD/rosette equipment on the Armstrong deck. An on-deck crane lowers the equipment into the water and replaces it on deck after each cast. We will be sampling for dissolved oxygen and other gases, chlorophyll, nutrients, and dissolved inorganic carbon from the rosettes.

I also enjoy meeting the science staff and crew aboard the Armstrong. Taking pictures of the science team members has helped me learn names, and by sharing so much space in the main lab I’ve been able to talk to several people about their work and experience(s) on WHOI research cruises.

One of our nearest research lab neighbors, Henry Holm, is studying lipids and the changes they undergo in different conditions. Cell membranes are composed of double layers of lipids, and under certain conditions such as temperature, depth, and availability of nutrients, the cell’s lipid membrane will change. For this research cruise he is focusing on taking samples from the underway system during our transect from Reykjavik port to the Irminger Sea array, and taking additional samples from CTD casts.

Photo of a smiling young man wearing a flannel jacket and hat, standing in front of a white filtration rack. The filtration rack consists of a row of 6 clear bottles secured upside-down over glass funnels filtering into white PVC pipes along the bottom of the shelf.

This is Henry Holm with his filtration rack. Henry is a joint-program grad student studying lipids at WHOI.

We are also sharing a lab bench with the various sensors for the Irminger array, which will be deployed over the course of the research cruise. On Thursday, Stephanie Petillo and Allen Smith (scientists with OOI) gave us a tour of the surface mooring and subsurface moorings that are on deck. The surface mooring is much larger than the subsurface moorings, and features sensors both above and below the water surface. Stephanie and Allen pointed out the nitrate and dissolved oxygen sensors, which I was able to recognize because they look very similar to the ones we are using. They also told us about the mechanics of releasing the entire surface mooring and associated sensors. Each sensor will be attached to the main line as they are released, and once all sensors have been attached and are off the boat, the enormous anchor weights will be released and will pull the line of sensors down, leaving only the surface mooring floating above.

Photo of the stern of the research vessel with an open view of the ocean in the background. A large blue and yellow surface mooring is suspended about 10 feet above the dock, tilted away from the camera, with the top leaning out over open water and the base attached to several lines which are held by crew members wearing orange safety vests and blue hard hats. Several spools of cable and winches are visible on the deck.

The surface mooring is being loaded onto the stern of the Armstrong! A team of WHOI scientists and crew members are directing the ship’s crane to place the mooring on the working deck.

Fun mini-story:

On the first day of chlorophyll filtration, I noticed that we caught a zooplankton in the underway seawater system. It was still floating around in our filter when I caught this picture of it. Fortunately, a zooplankton on our chlorophyll filter should not interfere too much with our measurements, as the body itself does not contain chlorophyll.

The underway sea system brought us a zooplankton! The zooplankton, shaped like a T and very tiny, is visible in the yellow circle. I (Emma) found it in our chlorophyll sample on Wednesday morning.

Cheers,
Emma

First Days at Sea!

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