My name is Jun Dong. I am a Ph.D. candidate in physical oceanography at Florida State University, working under Professor Kevin Speer on Polar Front dynamics in the Southern Ocean.
I am very glad that I can join this CLIVARI6S cruise. I work on a team with Prof. Speer and Katy Hill, who is a physical oceanography Ph.D. student from Australia. Our shift is from noon to midnight.
Photo caption: Jun is learning a variety of sampling procedures on this cruise. With Professor Bill Landing looking on, Jun draws a water sample for trace-metal analysis. Trace metal work is highly vulnerable to contamination, especially on a metal ship with lots of metal parts in a corrosive environment. Jun wears gloves to minimize the risk of sample contamination.
What I'm concentrating on during this cruise
Our major responsibility is the CTD (conductivity, temperature and depth) operation. This is my first time operating the CTD, so I am learning a lot from my teammates.
The CTD is mounted on a rosette, a framework we lower all the way to the seafloor. It measures in-situ conductivity, temperature, and pressure (depth is computed from the water pressure measured by a pressure sensor at any given level in the ocean; water pressure varies directly with depth).
From these data we calculate salinity and density, etc. The rosette also holds 36 two-liter bottles, which take water samples at different depths, which we determined according to conditions at the time in the area to be sampled.
Another great thing about this cruise is that we have three sonar current measurement systems onboard: a lowered acoustic Doppler profiler (LADCP), shipboard ADCP, and Rob Pinkel’s hydrographic Doppler sonar system (HDSS). Each system complements the others.
The LADCP, for example, is mounted on the rosette with the CTD, so it can measure currents from the sea surface all the way to the bottom. Tom, a graduate student from the University of Hawaii, shows us the LADCP measurements after every cast.
Adapting to unfamiliar conditions
The cruise is really great, and the only thing that bothers me is seasickness. I was really sick two days ago when a low-pressure system was passing by. Lots of people helped me to get over it. Prof. Speer gave me hot chamomile tea, and Katy gave me many useful suggestions. I am getting used to it now. The crew and scientists I work with are really nice, and the cooperation is very important to finish this journey.