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South Atlantic research cruise


CarTRidge cruise report
'Drifting over the Lake District in an airship at a height of 3000 metres and trying to drop a rock onto a barn roof. At night' ~ Chief Scientist Professor Jonathan Sharples Those are the words used by the Principal Scientific Officer of research cruise JC275 (CarTRidge) to describe our expedition across the south Atlantic Ocean in the austral summer of 2025. In fact, he is referring not to the terrestrial mountain range in north England, but rather to the divergent plate bou
Arianwen Zoe
May 1, 20255 min read


Another day another CTD
Today was definitely the craziest day we've had so far - and on a Sunday too. Alarms went off at 02:45am, which is feeling pretty normal by now, and we headed down to the main lab to watch the CTD profile as it went down. Whilst my filters were filling (15L per line takes me about 1.5hours), we filtered samples for SEM, which will allow us to visualise, count and identify our plankton to get an idea of their diversity and community changes over physical gradients. Having snap
Arianwen Zoe
Mar 3, 20252 min read


Squid and snowcatchers
The first of March brings with it an Aquarius moon (according to my moon journal!), the beginning of meteorological spring, and, for these eager scientists - our first pre-dawn CTD!! Standing in the main lab at 02:59, we watched the profile as it descended to about 300m (a veritable 'dip' compared to its 6km capability) and returned with its bounty - 24 20L Niskin bottles filled with water from various depths through the profile. Not only this, but we were treated to a displ
Arianwen Zoe
Mar 1, 20252 min read


Arrival at the mid-Atlantic ridge
Yesterday we transited to our ‘ridge’ site – almost time to test our theory of increased productivity on the mid-Atlantic ridge! We used the afternoon to host another mini-conference of science talks – and today was my turn to present. It was a really supportive and curious atmosphere and, though it was only a 10/15 minute talk, sparked much discussion afterwards. While we’re here, I’ll take the opportunity to tell you a little about my PhD. My focus is marine phytoplankton a
Arianwen Zoe
Feb 28, 20253 min read


Wirewalkers and gliders
Another dawn CTD, but this time a full run-through, enabled us a dress rehearsal for our long-anticipated pre-dawn. Sampling went off without a hitch (surprisingly there is not a huge amount of competition for sampling at 0400!), and while my samples were running I decided to embark on a DIY project to see if I could optimise my filtering set up. As a minimum I have 12 samples to do at a time, and only 6 lines on my inline peristaltic pump set up, so I wanted to try my hand a
Arianwen Zoe
Feb 26, 20252 min read


First CTD and mooring deployments
Today brought with it our first CTD! Through we weren’t looking to sample our full smorgasboard of filtering delights, it was very exciting to see that depth profile for the first time on this cruise, and allowed us to do a number of tests through our respective rigs to get a feel for filtering speed and biomass. ‘Filtering’ is not actually as straightforward as it sounds – there are a number of factors at play and it’s important to find a happy medium to get high quality sam
Arianwen Zoe
Feb 25, 20252 min read


Espresso club and cleaning Steve
Today was an exciting day because it was the inaugural meeting of ‘espresso club’ – aka, Team Plankton meeting outside the ship’s coffee room at 0400 to begin the gradual shift to our 0300 starts (we still had a couple of time zones to go at this point). Making the most of the bonus hours in our day, we decided to take the opportunity to get our FIRST DATA – even if not from this cruise. The JC273 team had left us a couple of trays of chlorophylls in the hold, which we measur
Arianwen Zoe
Feb 22, 20252 min read


Rainbows and floats
Today began encouragingly with a rainbow over the back deck, and the first order of business: building deck incubators. A deck incubator is essentially a paddling pool for sample bottles – we cover them with blue light filters (like you might find in a theatre) and pipe through underway water from below the ship – thus maintaining ambient light and temperature conditions you might find a few metres below the water’s surface. With the help of Grant (Chief Petty Officer, Scienc
Arianwen Zoe
Feb 21, 20252 min read


Sea survival and sickness
Not a huge amount of science was done today - everyone gets a day of grace to adjust to the ship's movement, which leaves most feeling at least a little groggy - but let me tell you a little about the experience of leaving port. We headed out to the front deck where we had the optimum view. When you leave a big port like Rio you get a 'Pilot' - someone who knows the way and comes up to the bridge to guide you out. He came on around 0900 and we were off. We sailed past many of
Arianwen Zoe
Feb 20, 20251 min read


A fond farewell to Rio
Our containers arrived which means not only do we have equipment but, in our case, we now have a lab. One of my most asked questions is whether the labs are built in to the ship and the answer is yes, many are, but some are also built into shipping containers which can be mixed and matched according to the needs of the specific expedition. That called for a 0500 start today, which was easy due to the excitement we all felt at finally getting going, and all hands on deck (now
Arianwen Zoe
Feb 19, 20251 min read


Expedition CarTRidge: Enhanced carbon export driven by internal tides over the mid-Atlantic ridge
Come along with us on our trip from Rio to Namibia via the mid-Atlantic ridge looking at the role microscopic photosynthesisers play in absorbing carbon from our atmosphere and storing it away in the ocean depths. Hello! If you're new here, I'm Ari, a PhD student at the University of Oxford, an avid science communicator and video reporter/producer for New Scientist . I'm about to embark on my second research cruise, for the expedition that will provide me with the bulk
Arianwen Zoe
Feb 11, 20252 min read
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