by Caroline Kivimae
Blue sky, blue sea, sun in masses and science. What else could anyone want?
When sampling the CTD today I have for the first time during this trip been able to take off my fleece, it feels summery despite the fact that it is only 9 degrees in the air. On this trip I am part of the ‘oxygen team’ taking samples and analyzing them to find out how much oxygen there is in the water at different depths. All plants, whether on land or in the ocean produce oxygen when they grow, so as chemists we can trace how much production has taken place by finding out how much oxygen has been released by the tiny phytoplankton that grow in the top 200 m of the ocean.
When the phytoplankton or zooplankton, the tiny animals that feed on them, die and sink they get broken down and this requires oxygen to take place. So, in the interior of the ocean, where the water has not had contact with the atmosphere for decades or longer there are some layers that have much lower oxygen that the surface water. This tells us about where the organic material from the surface goes and gets broken down by bacteria.
Today is Sunday, and as I mentioned, its very sunny. It is also the day where the best chocolate gets brought out in the main lab, well timed since we have a busy day. During the day we have passed over the shelf break, the area where the bottom of the ocean rises steeply from more than 2000 meters to 250 meters or less. This means sampling happens more frequently since the CTD we use to collect water samples takes 20 minutes rather than an hour and a half. Busy, busy, busy, but I would not want anything else.
Photos by Caroline Kivimae