Dataset: CTD KN195-03
Deployment: KN195-03

CTD Hydrocasts were performed with a Sea-Bird SBE 9 mounted near the base of a Niskin 24 Bottle Rosette. The CTD instrumentation included Conductivity (S/N 2186 & 2670), Temperature (ITS-90, S/N 4039 & 4195), Pressure (Digiquartz, S/N 785), Oxygen (SBE 43, S/N 0273), Fluorescence (Wetlab ECO-AFL/FL, S/N FLNTURTD-304), and Beam Transmission (Chelsea/Seatech/Wetlab CStar, S/N CST-1116DR). The data were processed with Seasave v. 7.18.

The downcast was conducted at 60 m per minute to a maximum depth of ~5 m above the seafloor (based on altimeter data). Features were selected from the downcast data for sampling on the upcast. These features included oxygen minimum layer(s), chlorophyll maximum layer(s) and the thermocline. In addition, standard depths of bottom, 50 m above bottom, 5000 m, 4000 m, 3000 m, 2000 m, 1500m, 1000m, 300m, 200m, 100 m, 50 m, 10 m, and surface were sampled.

Water samples were collected with a 24 bottle rosette with 10-L Niskin bottles. The water was filtered with flat membrane filters (Supor-200, 47-mm diameter, 0.2 µm P/N 60301) were placed into Swinex filter holders and attached to the petcock valve of the Niskin bottles with 1/4" tubing. The valves were opened and the water was pushed through the filters with the compressed air. The filtration rate is ~200 ml per minute. Filtered water samples were collected for molybdenum and nitrogen isotopes. When the water stopped dripping through the filter, the filters were removed, folded in half and placed into a whirl-pak bag and stored at -70 degrees C in the lower lab freezer.