As we move further into the open ocean, scientists on board are busy getting their instruments and equipment prepared for when we stop at our first observation “station.” These two scientists on the expedition’s chemistry team are attaching this white disk (called a secchi disk) to a rope, and at a station, will lower it into the water to measure the depth sunlight reaches. There is little current in the region of the Arctic, so the disk drags the rope fairly vertically downward. Using periodic markings on the rope, they will calculate how far down the disk is when they can no longer see it, and also the intensity of sunlight at different depths. They will use water samples taken at depths between the surface and 70m deep that correspond to 100% light intensity (meaning the water’s surface), 50% light intensity, 30%, 12%, 5% and 1% (when the light intensity is nearly zero). The goal is to learn about phytoplankton in the ocean, and how much carbon it takes in via photosynthesis. We still have some distance to cover before our first station, so later on we’ll tell you more about this and how it goes (and how scientists will continue to study the water samples in Korea).
