Once the CTD has been deployed, it should be lowered to 10 meters, and then the deck unit should be turned on. After 45 seconds, the CTD can be returned to just below the surface. Then the data acquisition program and VHS cassette CTD tape backup system should be started. The CTD should descend at a rate of 30 meters per minute for the first 200 meters and 45 meters per minute below that. The ascent rate should be 50 meters per minute. One exception to the descent rates occurs on the Bering Sea shelf in water less than 150 meters. In this case, the CTD should descend at 10 meters per minute during the entire cast. An entry in the Electronic Marine Observation Abstract (E-MOA) should be made for each CTD cast at the time of the maximum cast depth.
CTD data will be acquired on a PMEL provided computer using SBE's SEASOFT application. Aboard NOAA Ship MILLER FREEMAN, the capability to display CTD data using the ship's Scientific Computer System (SCS) and monitors will be available. Survey technicians and scientists will keep the CTD Cast Information/Rosette Log. Pressure, primary salinity, secondary salinity, primary temperature, secondary temperature, fluorescence, and light levels will be recorded on the CTD Cast Information/Rosette Log for all water bottle samples.
3.2.1.1 CTD Calibration - Salinity samples will be taken on every cast, or as specified by the Chief Scientist. No reversing thermometers will be required. The CTD systems will be equipped with dual thermistors. A Survey Technician will run Autosal salinometer analyses during the cruise and record the readings on an Autosal log.