Scientist Profile: Alexander Brearley

Finally, blog readers, it's the turn of your blog author to tell you a little bit about his involvement in the DIMES project!

Where do you work and what is your connection to DIMES?

I work at the National Oceanography Centre, Southampton as a DIMES postdoctoral researcher with Alberto Naveira Garabato. My contribution to DIMES is primarily to work on data from the UK mooring array, which forms an integral part of the project.

What’s the purpose of the moorings?

The two-year long deployment aims to uncover some of the underlying mechanisms that lead to mixing in the Southern Ocean. Many previous studies have suggested that ocean turbulence is enhanced when internal waves found between different density layers in the ocean break. We believe that the generation of these internal waves is greater over regions where the sea floor is relatively rough. To test this idea, the DIMES mooring array was located over a 10 km-wide sea floor bump in the Scotia Sea, in a region where the bottom currents are relatively strong. In addition, the moorings allow us to quantify the energy budget of the region, including the transfers of energy between the large-scale currents, eddies and internal waves.

Which sorts of instruments do you use to test these ideas?

In total, there are over 70 individual instruments on the UK moorings. These include current meters which measure water speed and direction and Microcats which measure temperature, salinity and pressure. In addition, we use a number of more sophisticated instruments including an Acoustic Doppler Current Profiler (ADCP) which measures currents at a number of different depth levels simultaneously, and a McLane Moored Profiler which moves up and down the mooring wire obtaining measurements of current speed, temperature and salinity every few seconds. Having such a wide range of different sensors is enabling us to understand the time-varying processes at work.

What sorts of things have you been doing on the cruise?

I have primarily been responsible for the data acquisition and processing of the mooring data. This includes helping the technical team to document, move and clean up the instruments as they come back on board, as well as downloading and quality-controlling the data. I am really looking forward to getting my teeth into the data when I get back to Southampton as we have had a really successful second year with only a couple of instrument failures.

In addition to my work duties, I have also taken some time to write the cruise blog – I hope you have all enjoyed reading it as much as I have enjoyed writing it!

What’s it been like writing the blog?

It has been a great opportunity to show to the world a little bit of what we do and to inspire other people to come and work in oceanography. From a science perspective, the Southern Ocean is one of the least well-understood parts of the planet yet it seems to have a critical role both in ocean circulation and in the carbon cycling. I hope that through the words and pictures that people have contributed to the blog we have managed to convey some of our enthusiasm for this fascinating place.