Let the Science Begin by Chanelle

All of my previous cruise experiences have been off the coast of the US Northwest. The open ocean in the Southern Ocean looks no different than that of the Pacific, so the beginning of the transit felt familiar to me. But we kept going farther and farther south and we finally got to the ice where we entered another world.

A view of the ice as we headed to our intended first 3 stations.

The ice was a source of endless wonder for everyone on board. You could tell the scientific specialty of a person based on their particular fascination with the ice. As a physical oceanographer, I was riveted by the diffraction and interference patterns of the waves of water travelling in-between the ice patches. Meanwhile, the biological oceanographers were nerding out over the brown algae in the ice.  The brown algae weren’t particularly exciting for everyone. However, no one was immune to the excitement over the penguins.

We saw tons of them. They’d be huddled around on their ice floes or swimming in the water. I didn’t expect to be able to see them while they swam, but they actually porpoise in the water leaping in and out.  We also saw countless seals lounging on the ice. One of the seals flopped ungracefully from the ice into the water making me question whether diving in the water was intentional or accidental. We were going through the ice trying to get to our first three stations, but unfortunately, there was too much ice so we had to skip those stations.

We circle around this CTD package after a cast to collect samples.

When I say stations, I am referencing the places where we stop to deploy the CTD and collect samples.  CTD stands for Conductivity (aka Salinity), Temperature, and Depth. The CTD rosette essentially consists of 36 bottles (called Niskin bottles), and a bunch of sensors that measure dissolved oxygen, fluorescence, and other measurements in addition to salinity, temperature, and depth. We deploy this CTD rosette into the water from a winch, and we typically send it to a depth of about 10 meters from the ocean bottom. Once we get the CTD to this bottom depth, we start a process called firing the bottles. From our computer console, we can close the different Niskin bottles at specified depths, thus collecting water samples throughout the water column as we ascend the CTD back to the surface.

 

Once the CTD is recovered, we begin gathering our samples from the bottles. We have a large variety of samples being collected on this cruise including pH, alkalinity, nitrate and oxygen isotopes, radiocarbon, salts, and CFCs.  As a result of the large variety of samples collected, this process takes time. Therefore, we are in a state of constant movement. The stations are spaced close enough together where we have to prep the CTD to be deployed again essentially as soon as we finish sampling.

We were two days into our sampling and getting into the groove of things when a big storm started coming our way. Unfortunately, this meant that we had to put a hold on sampling. We are currently on our way back to the ice to avoid the storm and hopefully squeeze in some stations. I’m bummed we lost some time for science, but I have to admit, I am looking forward to returning to the ice.