This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2021_V03, titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27o S." The voyage took place between May 8 and June 3, 2021 departing from Hobart (TAS) and arriving in Brisbane (QLD). Data for 36 deployments were acquired using the Sea-Bird SBE911 CTD 24, fitted with 19 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. The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (SD) of 0.0019084 PSU, when rounded this is outside our target of ‘better than 0.002 PSU’, so the cut-off was adjusted to 0.003 PSU. The standard product of 1 decibar binned averaged were produced using data from the primary sensors. Cast 10 was ended prematurely so CapPro could not process cast properly. To overcome this, in MATLAB, the end of cast 9 was attached to the end of cast 10. This data will not appear in the raw files from SeaSave and should not affect processing, as CapPro will remove out of water data before processing but needs this data to find the end of the cast. During cast 12 the CTD landed on the bottom of the ocean floor, no damage was found, and all subsequent casts performed as expected. Prior to cast 31, due to some discrepancies between the primary and secondary sensors, the Seagoing Instrumentation Team swapped the secondary pump. This resolved the particular issue. Bottle seven had intermittent problems firing reliably. Initially the release magnet was swapped and all further casts had a backup fired with bottle 7, however it was later found that the root cause was corrosion under the epoxy. As a precaution, the whole trigger mechanism was swapped. The dissolved oxygen data calibration fit had a SD of 0.84461μM. The agreement between the CTD and bottle data was good. PAR, Transmissometer, CDOM, Altimeter and Ecotriplet were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2021_V04, titled: "Biodiversity Assessment of Australia’s Indian Ocean Territories." The voyage took place between June 30 and July 29, 2021 departing from Darwin (NT) and arriving in Hobart (TAS). Data for 25 deployments were acquired using the Sea-Bird SBE911 CTD 24, fitted with 31 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. The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (SD) of 0.0013062 PSU, within our target of ‘better than 0.002 PSU’. The standard product of 1 decibar binned averaged were produced using data from the primary sensors. The dissolved oxygen data calibration fit had a SD of 0.089089μM. The agreement between the CTD and bottle data was good. There was an observed spike in values indicating a blockage in the secondary sensors of CTD deployment 11 around 2700 decibar and it is recommended to use the primary sensor data. An Altimeter, Nephelometer, Transmissometer, CDOM, Fluorometer, and Turbidity meter were also installed on the auxiliary A/D channels of the CTD. The Seapoint nephelometer values were found to be out of the expected range for the sensor. The collected data were subsequently processed and archived within the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2019_V05, titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27 degrees South." The voyage took place between September 9 and September 29, 2019 departing from Brisbane (QLD) and arriving in Brisbane. Data for 28 deployments were acquired using the Sea-Bird SBE911 CTD #25, fitted with 24 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. A Biospherical PAR, Tritech Altimeter, C-Star Transmissometer, WET Labs CDOM, WET Labs ECO Scattering, and WET Labs ECO Chlorophyll sensor, were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2022_V08, titled: "Biodiversity Assessment of Australia’s Indian Ocean Territories." The voyage took place between September 30 and November 3, 2022 departing from Darwin (NT) and returning to Fremantle (WA). 44 CTD deployments were conducted on this voyage. The data were acquired with the CSIRO CTD unit #22 (S/N 1039), a Sea‐Bird SBE911 with dual conductivity and temperature sensors. The CTD was additionally fitted with SBE43 dissolved oxygen sensors including Altimeter, Nepthelometer, Transmissometer, CDOM, chlorophyll‐a, and Scattering. The collected data were subsequently processed (quality-controlled), and 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 CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2016_V03, titled: "Monitoring Ocean Change and Variability along 170o W from the ice edge to the equator." The voyage took place between April 26 and June 30, 2016 departing from Hobart (TAS) and arriving in Lautoka (Fiji). Data for 141 deployments were acquired using the Seabird SBE911 CTD 20, fitted with 36 twelve litre bottles on the rosette sampler. CSIRO supplied calibrations were applied to the temperature, conductivity, oxygen, and pressure data. The data were subjected to automated QC to remove spikes and out-of-range values. The final conductivity calibration is based on multiple deployment groupings, due to sensor and deck box changes. Processing was performed on each unique sensor configuration in order to best account for the individual characteristics of each sensor. The final calibration from the primary sensor for casts 1-7 had a standard deviation (S.D) of 0.00088 PSU, a S.D of 0.00117 for casts 8-46, and S.D of 0.00114 for casts 47-141, well within our target of ‘better than 0.002 PSU’. The standard product of 1 dbar binned averaged were produced using data from the primary temperature and conductivity sensors, and the secondary Oxygen sensor. Similarly, the dissolved oxygen data were calibrated in groups of deployments due to sensor changes. The agreement between the CTD and bottle data was good. A Fluorometer, Transmissometer, and altimeter were also installed and logged on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2018_V03 titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27S." The voyage took place between April 19 and May 10, 2018 departing Brisbane (QLD) and returning to Brisbane. Data for 14 deployments were acquired using the Seabird SBE911 CTD unit 24 fitted with 24 twelve litre bottles on the 32 bottle rosette sampler. Samples were collected on all casts. Sea-Bird-supplied and CSIRO calibration factors were used to compute the pressures, preliminary conductivity oxygen and temperature data. The data were subjected to automated QC to remove spikes and out-of-range values. The final conductivity calibration for each deployment was calculated using the sensors with the lowest residuals when compared with the values measured by the hydrochemistry team. The final calibration from chosen sensors all had a standard deviation (SD) less than our target of ‘better than 0.002 PSU’. The dissolved oxygen data calibration generally showed a good agreement between the CTD and bottle data. Biospherical photosynthetically active radiation (PAR), Wetlabs transmissometer and Chelsea fluorometer sensors were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2018_V07, titled: "SOTS: Southern Ocean Time Series automated moorings for climate and carbon cycle studies south west Tasmania; The voyage took place from Hobart (TAS) to Hobart between August 20 and August 24, 2018. Data for 1 deployment was acquired using the Seabird SBE911 CTD unit 24, 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. The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (S.D) of 0.0011658 PSU, within our target of ‘better than 0.002 PSU’. The standard product of 1dbar binned averaged were produced using data from the primary conductivity and secondary oxygen sensors. The dissolved oxygen data calibration fit had a S.D. of 0.33778 uM. The agreement between the CTD and bottle data was good. A Biospherical photosynthetically active radiation (PAR) meter, Seapoint Turbidity Meter (Nephelometer) and a Chelsea Fluorometer were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2018_T01 titled: "Physical and biogeochemical gradients in the East Australian Current." The voyage took place between April 6 and April 14, 2018 departing from Hobart (TAS) and arriving in Brisbane (QLD). Data for 21 deployments were acquired using the Sea-Bird SBE911 CTD 24, 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. The Salinometer was found to have been malfunctioning and not reliably reporting results on IN2018_T01. The final conductivity calibration was based on calibrations derived on the subsequent voyage: IN2018_V03. The final calibration from the primary sensor had a standard deviation (SD) of 0.0013986 PSU for the primary and 0.0014150 PSU for the secondary, well within our target of ‘better than 0.002 PSU’. The standard product of 1 decibar binned averaged were produced using data from the primary sensors with secondary sensors included with the suffix ‘_2’. The dissolved oxygen data calibration fit had a SD of 0.70186 uM for the primary and 0.81698 uM for the secondary. The agreement between the CTD and bottle data was good. Fluorometer, Altimeter, Transmissometer and PAR sensors were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2018_V04, titled: "Constraining external iron inputs and cycling in the southern extension of the East Australian Current." The voyage took place from Hobart (TAS) to Hobart between September 11 and October 8, 2018. Data for 25 deployments were acquired using the Sea-Bird SBE911 CTD 24, 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. The final conductivity calibration was based on a single deployment grouping. The final calibration from the primary sensor had a standard deviation (SD) of 0.0012361 PSU, well within our target of ‘better than 0.002 PSU’. The standard product of 1 decibar binned averaged were produced using data from the primary sensors. The dissolved oxygen data calibration fit had a SD of 0.7997µM. The agreement between the CTD and bottle data was good. A Wetlabs CSTAR Transmissometer, Chelsea Aquatracka III Fluorometer, Wetlabs CDOM Fluorometer, and PAR sensor were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.

This record describes the Conductivity-Temperature-Depth (CTD) data collected from the Marine National Facility RV Investigator voyage IN2019_V07, titled "RAN Hydrographic and Maritime Heritage Surveys." The voyage took place from Hobart (TAS) to Hobart between April 11 and April 23, 2019. Data for 10 deployments were acquired using the Sea-Bird SBE911 CTD 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. Casts 1, 2, and 3 were test casts to verify the recently serviced secondary altimeter data and no bottles were fired during those deployments. A Wetlabs CSTAR Transmissometer, Wetlabs CDOM Fluorometer, and PAR sensor were also installed on the auxiliary A/D channels of the CTD. The collected data were subsequently processed and archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset may be contained in the Voyage Summary and the CTD Data Processing Report.