We just started the CTD section. The CTD gets its name from the measurement of Conductivity (salinity), Temperature and Depth. Nowadays it measures many more interesting parameters, such as oxygen and fluorescence. The CTD frame is lowered to the bottom by cable at a speed of about 1 m/s. For a 3 km depth station that takes about 50 minutes. Once you make it to the bottom you need to get it back up. During the way up we stop the frame at several depths to take samples for calibration.

During this cruise we’ll do just over 30 stations. Most are meant to get an overview of the ocean’s properties along the sections. Others are meant for calibration of the instruments on the moorings. The high accuracy data from the ship’s CTD, taken before and after mooring deployment, gives us good insight into how the sensors in the mooring behaved over the year. If all is well they’ll tell us that they behaved properly.