RV Investigator Voyage IN2026_T02 CTD Data

This record describes the CTD data collected on Investigator voyage IN2026_T02, titled: "CAPSTAN IN2026_T02." The voyage took place between April 23, 2026 and May 05, 2026 (AEST), departing from Fremantle and returning to Hobart.

Data for 14 CTD deployments were acquired using the Sea-Bird SBE911 CTD unit #23, fitted with 36 twelve-litre bottles on the rosette sampler. Sea-Bird-supplied calibration factors were used to compute the pressures and preliminary conductivity values. CSIRO-supplied calibrations were applied to the temperature data. The data were subjected to automated QC to remove spikes and out-of-range values.

NaN values were observed in the processed data for the Altimeter and Transmissometer after casts 5-7. These sensors were swapped out and no more NaNs were observed.

CTD was left at 60m depth for 30 minutes during cast 3 to record audio on a hydrophone externally mounted to the CTD frame.

In addition to cast 1, CTD cast 4 was a test cast for crew examination of the spooling on the inboard CTD winch, in preparation for deep casts on voyage IN2026_V06. No bottle samples for calibration were taken on this cast.

During processing, it was noted that turbidity was not added into the Seasave configuration file for the CTD acquisition, and as such this data was not acquired.

The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (SD) of 0.0020135 PSU, marginally outside our target of ‘better than 0.002 PSU’. The standard product of 1-decibar binned averages were produced using data from the primary sensors.

The dissolved oxygen data calibration fit had a SD of 0.87589 μM. The agreement between the CTD and bottle data was good.

PAR, CDOM, Transmissometer, Fluorometer and Turbidity sensors were also installed on the auxiliary A/D channels of the CTD.

The collected data were processed (quality-controlled), and subsequently archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC).

Additional information regarding this dataset may be contained in the Voyage Summary and the Data Processing Report.