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 Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator research voyage in2018_t01, titled: "Physical and biogeochemical gradients in the East Australian Current." The voyage took place from Hobart (TAS) to Brisbane (QLD) between April 6 and April 16, 2018. Hydrology samples were collected from Niskin bottles sampled at various depths during a Conductivity-Temperature-Depth (CTD) deployment. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. Underway samples were also collected every 12 hours (or once every 24 if a CTD coincided with collection time) for nutrient analysis from the underway system which collects water from 7 m depth and is not filtered. This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart. Additional information regarding this dataset is contained in the Voyage Report and Data Processing Report.

This record describes the Acoustic Doppler Current Profiler (ADCP) 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 from Hobart (TAS) to Brisbane (QLD) between April 5 and April 14, 2018. Data was collected during IN2018_T01 for the duration of the voyage. Data was collected using UHDAS and post-processed using CODAS. The RDI Ocean Surveyor 150kHz ADCP was out of service, being replaced by a WorkHorse Quartermaster 150kHz ADCP for the duration of the voyage. The RDI Ocean Surveyor 75kHz ADCP was run in broadband mode during the port period and the first day of the voyage whilst leaving Hobart and in narrowband mode from 0016 07/04/2018 for the duration of the voyage. Internal triggering was used. The drop keel was at 2m below the waterline for most of the voyage and lowered to 4m in periods of deep water. See the voyage computing and electronics report for more details regarding data acquisition. This dataset was processed and then archived within the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart.

This record describes the data (CTD, Dissolved Oxygen, Transmissometer, PAR, ECO Triplet, Nitrate, Fluorescence and LOPC) collected using the towed TRIAXUS platform on 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 2 Triaxus deployments were acquired in CAP CTD acquisition software using the Seabird SBE911 CTD 23. The deployments were conducted with a standard tow speed of between 7 to 10 knots and wire out ranged from 600 to 1740 m. Second deployment ended early due to loss of fibre communications. Dissolved oxygen sensors, Transmissometer and Cosine Photosynthetically Active Radiation (PAR) sensor were also installed on the auxiliary A/D channels of the CTD. In addition to the auxiliary channels, ECO Triplet, Nitrate and LOPC were mounted on the Triaxus as attached payloads. 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 Data Processing Report.

This record describes the End of Voyage (EOV) archive from the Marine National Facility (MNF) RV Investigator research voyage in2018_t01, titled "Physical and biogeochemical gradients in the East Australian Current." The voyage took place from Hobart (TAS) to Brisbane (QLD) between April 5 and April 14, 2018. For further information refer to the Voyage documentation links below. Instruments used and data collected include: Regular measurements: Acoustic Doppler Current Profiler (ADCP; 75, 150 KHz ), Lowered ADCP (LADCP), Disdrometer, Fisheries echosounder (EK60), Multibeam Echosounder (EM710, EM122), Sub-bottom Profiler (SBP120), Gravimeter, GPS Positioning System, Doppler Velocity Log, Met station (temp, humidity, pressure, wind, rain, PIR, PSP, PAR), Nephelometer, pCO2, Starboard and Portside Radiometers, Radon, Ozone and Oxygen sensors, Weather Radar, Greenhouse Gas Analysers (Aerodyne, Picarro), Air Pressure, Wind Speed and Direction sensors, Photosynthetically Active Radiation (PAR) sensor, Precision Infrared Radiometer (PIR),Precision Spectral Pyranometer (PSP), Infrared Sea Surface Temperature Autonomous Radiometer (ISAR), Seawater (TSG, fluorometer, optode), Thermosalinographs (TSG), CTD, Hydrochemistry, Expendable Bathythermographs (XBTs). Voyage-specific measurements: Condensation Particle Counters (CPC), Cloud Condensation Nuclei counter (CCN), ITI Trawl net, Multiangle Absorption Photometer (MAAP), Scanning Mobility Particle Sizers (SMPS), Triaxus, Video. The archive for the IN2018_T01 EOV raw data is curated by the CSIRO Oceans and Atmosphere (O&A) Information and Data Centre (IDC) in Hobart, with a permanent archive at the CSIRO Data Access Portal (DAP, https://data.csiro.au/dap/), providing access to participants and processors of the data collected in the voyage. All voyage documentation is available electronically to MNF support via the local network. Access to voyage documentation for non-CSIRO participants can be made via DataLibrariansOAMNF@csiro.au.