I recently had the opportunity of joining the 42 day I06S hydrographic cruise, as part of the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP). This cruise took measurements of the Indian and Southern Oceans. These measurements are taken every decade to calculate changes in heat, freshwater, carbon, oxygen, and nutrients. Most of what we did involved lowering a CTD (so called because it measures conductivity, temperature, and density) to the ocean’s floor. The CTD was mounted on a rosette with a few other instruments, and with 36 niskin bottles. These bottles are fired at different depths, and the water from each depth is used to calculate quantities like carbon, oxygen, and pH.
I joined the cruise as a CTD student. This meant that my primary job was to monitor the CTD as it was lowered down to nearly the bottom of the ocean and then brought back on board. Depending on the depth, this could take up to 4 hours. Once the CTD was back on board, we would take water samples from the niskin bottles. I generally took salinity samples, which are used to calibrate the conductivity sensor on the CTD. We generally aimed to do 2 CTD casts per 12 hour shift.
We encountered many unexpected challenges at sea. On our second day, we blew an engine pump and had to turn around and head back to Cape Town. We also had lots of bad weather - up to 22 meter seas! When the weather got that bad, we couldn’t work or really do much besides play cards, darts, ping pong, penguinopoly, settlers of catan… anything to pass the time. We also had many transit days that we passed by reading, working out, watching movies, playing ping pong, printing out memes, and getting to know each other. Sometimes it felt like summer camp (a summer camp with 12 hour work shifts and very limited internet).
Despite all the challenges, I had an amazing experience and learned a lot. My favorite day was when we were closest to Antartica. The ocean around us was full of pancake ice. The water was very calm and it felt like we were on some faraway planet. We also saw the Southern Lights, and some of the most incredible stars I have ever seen. I also loved meeting students and scientists from all around the world. At the beginning of the cruise, I only knew one person. By the end, everyone felt like family.
After the cruise, I spent 3 weeks in Cape Town and taught Basic Dynamical Oceanography at the University of Cape Town. This was my first time teaching a class by myself. I had been a TA in the past - but it was very different to teach on my own!
My students were very engaged, asking questions during class and sometimes coming by my office. In addition to the direct class material, we discussed cruises, grad school, and research.
After our last lecture, Prof. Isabelle Ansorge, the head of department, took myself and the students to lunch. It was nice to get to know the students outside of the classroom. They gave me a textbook from Johann Lutjeharms, who was a professor at the University of Cape Town and arguably the world’s expert on the Agulhas Current.
Submitted by K McMonigal, PhD candidate in Meteorology and Physical Oceanography at the Rosenstiel School of Marine and Atmospheric Science
