Dataset: OOI Global Station Papa Array CTD and Discrete Water Sampling Data from R/V Melville, R/V Thomas G. Thompson, NOAA Ship Ronald H. Brown, R/V Sally Ride, R/V Sikuliaq MV1309, TN323, MV1404, RB1605, SR1710, SR1811, SKQ201920S, SKQ202111S, SKQ202208S, SKQ202

OOI-CGSN CTD Sampling Guidelines

In general, water samples are collected for analysis at depths that correspond to instrumentation making in situ measurements.  For example, Near Surface Instrument Frames (NSIFs) have instrumentation that measure dissolved oxygen (DO), salinity (CTD), nitrate (NUTNR), the partial pressure of CO2 (CO2), and chlorophyll a fluorescence, so water samples should be collected at the depth of the NSIF for analyses of all those parameters.  Additionally, as noted above, OOI water sampling data are valid long-term datasets in and of themselves. Thus, some measurement locations are driven by broader science questions.

Soak Time – The CTD rosette should be allowed to equilibrate (e.g., the CTD sensor readout stabilizes) at the desired target depth for at least 1 minute or more depending on conditions.  Longer soak times may occur to accommodate acoustic release testing or other activities.