Ben and his love of CTDs and sunshine

Ben (left) and Darren (the shy guy who hasn't written in the blog yet) enjoying themselves in temperate climes during our port call in Santa Cruz de Tenerife

I am usually found sailing into stormy seas in the high latitude North Atlantic and the Southern Ocean. The last time I sailed on Discovery the wind hardly dropped below force 10 (wind speed of about 60 mph). So this time it’s quite refreshing to pack a bag containing shorts and sun cream, rather than wooly hats, scarves and thermals. My role on this RAPID cruise is to oversea all the underway data collection and processing the CTD data. What’s a CTD?  I’m glad you asked.

A CTD is the physical oceanographers main instrument. Alex is stood next to one in a previous post. It is lowered from the ship on wire to within about 10m of the seabed and then hauled back on board. This can take a while, as the seabed is currently 5000m below us! During this journey instruments measure how the temperature and conductivity of the water varies with depth. Temperature and conductivity are used to calculate the waters salinity (or saltiness). The MicroCat instruments (picture here) on the moorings are in effect little CTDs so we attach them to the CTD and use their bigger, and slightly more accurate, brother to check that they are working correctly.

We not only check that the new MicroCat instruments going out on the new moorings are OK we also attach the ones we have recovered onto the CTD and fly them into the depths as well. As if they haven’t had enough, they have been out in the darkness all alone for a year already!

Ben Moat