June 1st @ 10:00am - Right after breakfast this morning I joined Reyna and Tania in processing water samples from the ‘Rosette’. This large piece of equipment is called the ‘Rosette’ because of the circular arrangement of ‘Niskin Bottles’ (long pipes with caps on each end).
It is used to get a vertical profile of the water column whenever required. The device is lowered down by a winch, with the top and bottom caps held open so water can flow through the bottles as the device descends. At a particular depth of interest, a release mechanism can be triggered, automatically or remotely, that slams both the bottom and top caps on a single bottle closed, sealing it. With 24 sampling bottles in the rosette, 24 individual water samples from a series of depths can be obtained. The most common analysis done on these water samples is a measure of dissolved oxygen.
On the bottom of the frame sits a CTD (Conductivity, Temperature, and Depth) device that continuously measures these three key parameters, which can be correlated with each sample to give a basic look at the key physical characteristics of water at different depths. This is one of the basic devices that you would find on almost any oceanographic ship in the world.
Blog post and photos by Scott Doehler
Marine Educator
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