Crossing the Drake passage in a container by Felix Leung
It’s almost the end of the voyage on RRS James Clark Ross at the Drake Passage expedition, it’s about time for me to summarise what I have done and experienced on this amazing journey. I am part of the Transient Tracer Team (TTT) from University of Exeter that is lead by Dr Marie-Jose Messias. In addiiton to Marie-Jose we are a group of four: Gary, Gen, Jack and me. We divided ourselves into two shifts and I am fortunate to have the daytime shift from midday to midnight.
Our role is to collect sea water samples from different depths using the CTD (a rosette of 24 cylinders that is opened at different depth to collect around 20 litre of sea water per cylinder) and measure how much transient tracers such as CFC, SF6 are in the sea. CFC and SF6 are produced by humans, used as refrigerant and insulators. They don’t exist in nature and that’s why it is used like a tracer to see how the ocean currents travel around the world.
To measure the concentration of tracers in sea water we use a purpose-built gas chromatography system called the Barbarella (named after the fictional superheroine). When I first saw the instrument, I was overwhelmed with all the tubes, gas cylinders and valves that connected the sample and gas chromatography system. There are only around 5 instruments in the world that do this kind of measurement and it needs constant calibrations to make sure the measurements are accurate. To accommodate the instrument, which is of considerable size, we have it in a container and set up a lab out on deck.
Inside the container it feels small, it has computers, air conditioning, internet, telephone and (fortunately) windows. On a calm day, we could see many petrels and albatross following the ship. We also watched many beautiful sunsets and sunrises. On a rough day, working in the container proved challenging. The Drake passage is named after British explorer Francis Drake who discovered the strait in 1578. It is infamous for being the roughest seas in the world. Since its latitude is just ocean and without any large landmass, the Antarctic Circumpolar Current (ACC) carries large volumes of water and keeps warm water away from Antarctica, the ACC also makes the sea very choppy especially at the Drake Passage which is the narrowest strait between Antarctica to South America, sailors call it the “Drake shake”.
Working in the container probably gave us the best experience of the “Drake Shake”. At the beginning I was excited to experience the rough sea but then I started to feel a little sick. Fortunately, we have a doctor onboard, and Dr Amber gave many of us motion sickness patches, which worked like magic!
We were told that the sea would get rough. Within a few hours of setting sail the crew locked the doors to the upper deck to prevent water entering the ship. Just outside the container the sea water is often at ankle height and sloshes about. The equipment in the container are all strapped securely, but it was quite scary at night when winds reached Beaufort 9. It felt like being on a roller coaster for much of the time, this makes simple tasks such as walking up the stairs, opening doors and pouring a glass of water difficult. However, we are not afraid of the sea, the ship is armed with an ice-strengthened hull and is under the command of an experienced captain and crew. With our current technology such as GPS and weather forecast, crossing the Drake passage is much less treacherous than the early days of James Clark Ross’s expedition to Antarctica in 1843.
Working in the container had its perks too. We were the first to see humpback whales, probably a mother and calf. It was my first-time seeing whales in the wild, and it was truly an emotional experience meeting one of the Earth’s largest animals. Since banning of whaling their numbers are recovering.
Overall, I have really enjoyed my time on this cruise JR18002, highlights include spotting a huge icebergs, the whales and seeing Elephant Island in the mist. I have learnt a lot from the people I have been with, and it feels great that I am part of an important mission to understand climate change and its impact to the ocean.
Dr Felix Leung is a post doctoral researcher at University of Exeter and Hong Kong.