The AMOC transports heat from the tropics and keeps Western Europe warm. In autumn 2015 the RRS Discovery will recover the moorings from the RAPID array across the Atlantic at 26 North. The data will tell the RAPID science team how the AMOC has changed over the past 18 months. Their challenge to you: can you predict these changes?
See what the experts predict, and follow the 26N team as they recover the moorings and analyse the data to learn the truth.
Tuesday, 10 November 2015
A geochemists life during the RAPID Challenge
Having the opportunity to be part of this year’s RAPID
Challenge team has given me the chance to step out of day-to-day PhD life and
into a modern scientific adventure. My main role on board is to collect
seawater samples from a CTD (an instrument suite with water sampling bottles primarily measuring conductivity, temperature and depth - and for this cruise oxygen). The CTD takes a profile (anything from 5800m up to the surface)
and then I determine the amount of dissolved oxygen in each sample.
The CTD being deployed over the side of the ship.
right? But unfortunately the challenges started immediately. During the transit
to Tenerife, I attempted to set up a new titration system in the clean
chemistry lab on board. Challenge 1: getting used to the very enclosed, very
lonely, very warm clean lab whilst fighting to find my sea legs. Challenge 2:
getting consistent results with the titration unit.
Having failed on both
counts, I explored a double plan B: New, spacious, cooler lab; and a different
titration unit. Much better! My day starts with chasing all the bubbles out of
the sampling tubes in the titrator. So far, this has been a long and
frustrating process, struggling to shift smaller bubbles out of the tubes, and
generally finding one gets stuck right at the very end of the aspirator (the part of the tube that enters the sample).
Sara using the oxygen analysis kit
I check to see if the titration unit is behaving by measuring numerous “blank”
and “standard” samples to make sure the numbers are consistent. The main stage
is measuring the real samples collected from the CTD and then plotting the
My favourite part is collecting the samples from the CTD
(although this is usually done at unsociable hours in the middle of the night).
It’s refreshing to go outside, and I always feel a sense of wonder when
handling water that was 5km below me only a few hours previously. Whilst
filling the glass flasks, we must measure the temperature of the water. This has
turned into a game to keep the spirit alive at 3am – whoever guesses the
closest temperatures wins a Hobnob. I wish I was better at this game….!