This record describes gravity data collected on RV Investigator voyage IN2018_V03 which departed Brisbane on the 19th April 2018 and returned to Brisbane on the 10th May 2018. The gravity meter instrument is a MicroG Lacoste Air-Sea II. Data are stored in .ENV and .DAT data files at CSIRO. There are 34 files totalling 241 MB of raw data in this dataset. No processing has been conducted on this data. Additional information regarding this dataset is contained in the GSM data acquisition and processing report.

This record describes sub bottom profiler data collected on RV Investigator voyage IN2018_V03, which departed Brisbane on the 19th April 2018 and returned to Brisbane on the 10th May 2018. The Kongsberg SBP120 (sub bottom profiler) was used to acquire data containing the specular reflections at different sediment interfaces below the seafloor. The SBP120 provides a 3° by 3° angular resolution. The echosounder's frequency sweep range is from 2.5 to 7 kHz. The SBP120 was logged almost continuously for the extent of the voyage. Data are stored in *.raw (53 files 7.47 GB) raw and *.seg (53 files 7.43 GB) segy formats at CSIRO. The segy format data had a real time processing stream applied, which applies gain, a gain correction, matched filter with replica shaping, an attribute calculation for instantaneous amplitude and time variable gain. Additional information regarding this dataset is contained in the GSM data acquisition and processing report. Additional data products may be available on request

This record describes multibeam echosounder data collected on RV Investigator voyage IN2018_V03, which departed Brisbane on the 19th April 2018 and returned to Brisbane on the 10th May 2018. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information between/around waters off Brisbane, Queensland. The EM122 provides a 1 degree by 1 degree angular resolution. The echosounder's nominal frequency is 12 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 399 files totalling 15.6 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format are corrected for motion and position. Tide corrections were not applied to the processed data. Processed data had outliers removed. Processed line data are available in *.gsf and ascii format, and processed bathymetry and backscatter grids in geotiff format. Additional information regarding this dataset, including information on processing streams, is contained in the GSM data acquisition and processing report. Additional data products may be available on request.

This record describes the Acoustic Doppler Current Profiler (ADCP) 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 27oS." The voyage took place between April 19 and May 10, 2018 departing Brisbane (QLD) and returning to Brisbane. Data was collected during in2018_v03 for the entire voyage. Data was collected using UHDAS and post-processed using CODAS. The os150(150kHz) ADCP was not operational during this voyage and was replaced with a wh150(150kHZ). The wh150 was calibrated in the preceding transit. The 75khz ADCP was operated in narrowband mode with 8m bins for the duration of the voyage. Internal triggering was used as external triggering was found to be unstable on previous voyages. The drop keel was at 4m for most of the voyage but raised to 2m during periods of rough weather. Acquisition was stopped and started upon a keel depth change to ensure no data was corrupted. 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 Hydrology (HYD) data collected 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. Five nutrients were analysed; silicate, phosphate, nitrate + nitrite, nitrite and ammonium. Certified reference materials for nutrients in seawater were within the specified limits of the certified value. The Guildline salinometers were problematic at sea, samples from CTD 12, 13, 14, the underway thermosalinograph and Triaxus samples were collected in crimped top bottles and brought back to Hobart for analysis. High quality data was produced for the three measured parameters. 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 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 data (CTD, Dissolved Oxygen, Transmissometer, PAR, ECO Triplet, Nitrate, Fluorescence and LOPC) collected using the towed TRIAXUS platform on Investigator voyage IN2018_V03, titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27oS." The voyage took place from Brisbane (QLD) to Brisbane between April 19 and May 10, 2018. CTD, Dissolved Oxygen, Transmissometer, PAR, and ECO Triplet have been processed and are made available via the links below. The collected data were subsequently 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 Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2018_V03, titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27o S." The voyage took place between April 19 and May 10, 2018 departing from Brisbane (QLD) and arriving in Brisbane. Standard Underway data is continuously recorded, consisting of: (1) Navigation data (NAV): Latitude, Longitude, Speed, Heading, Course Over Ground, Gyros, and Doppler Log (dual GPS instrument). (2) Thermosalinograph (TSG): Water Salinity, Flow-Rate, Temperature, Fluorescence, pCO2 and Optode/Oxygen. (3) Atmospheric (MET): Humidity, Wind Speed and Direction (vane and ultrasonic), Radiometer/Sea Surface Temprature, Pyranometer/Solar Radiation, Photosynthetically Active Radiation (PAR), Air Temperature, Air Pressure, Rain, Ozone and Trace Gases (port and starboard instruments). The quality-controlled RV Investigator underway meteorological and SST data are supplied to the IMOS AODN where they are publicly available at the "Ships of Opportunity" Thredds server (http://thredds.aodn.org.au/thredds/catalog/IMOS/SOOP/SOOP-ASF/VLMJ_Investigator/catalog.html) for research. From there, they are downloaded by NOAA for their In Situ Quality Monitoring web site (iQUAM2) and made available for satellite SST validation. The SBE 38 SST data are used within the Australian Bureau of Meteorology for real-time satellite SST validation and ingested into real-time SST analyses which are then used as the boundary condition for Numerical Weather Prediction models. The meteorological and SST data are uploaded onto the Global Telecommunications System (GTS) for global dissemination to Meteorological Agencies, and separately supplied to the SAMOS (http://samos.coaps.fsu.edu/html/) Project for air-sea flux research. The real-time SBE 38 SST data are currently (2017) used in the following data products (accessed via the GTS): • International Comprehensive Ocean-Atmosphere Data Set (ICOADS R3.0) (http://icoads.noaa.gov/) • NOAA NCEI Extended Reconstructed Sea Surface Temperature version 4 (ERSST.v4) (https://www.ncdc.noaa.gov/data-access/marineocean-data/extended-reconstructed-sea-surface-temperature-ersst-v4) • Hadley Centre SST Data Set (HadSST3) (http://www.metoffice.gov.uk/hadobs/hadsst3/) • Global Ocean Surface Underway Data (GOSUD) Project (http://www.gosud.org/) • Bureau of Meteorology daily and weekly SST analyses (http://www.bom.gov.au/marine/sst.shtml) • NOAA NCEI “Reynolds” daily global OISST analysis (https://www.ncdc.noaa.gov/oisst) • NASA JPL “MUR” 1 km daily global SST analysis (https://mur.jpl.nasa.gov/) • UK Met Office “OSTIA” daily global SST analysis (http://ghrsst-pp.metoffice.com/pages/latest_analysis/ostia.html) • CMC daily global SST analysis • Ourocean “G1SST” global daily 1 km SST analysis (https://ourocean.jpl.nasa.gov/SST) As part of the underway data gathering system, other datasets are produced (e.g., pCO2, ISAR SST) which are processed separately and have their own metadata records. Data are recorded at 5 second intervals. Near real-time data are available via the link "Visualisation tool for Underway Data." This dataset will be processed and archived within the CSIRO Oceans & Atmosphere (O&A) Information and Data Centre (IDC) in Hobart (TAS). Data are available at time intervals of 5 sec (NetCDF format), 10 sec and 5 min (ASCII format). Additional information regarding this dataset is contained in the Voyage Summary and/or the Data Processing Report for this voyage.

This record describes the ISAR/SST Sea Surface Temperature data collected on the RV Investigator Voyages from 2014 onwards. The infrared SST autonomous radiometer (ISAR) is a self-calibrating instrument capable of measuring in situ sea surface skin temperature to an accuracy of 0.1 K. The SST Radiometer is mounted on the port bridge wing, approximately 19.593m above the summer load line. The RV Investigator ISAR skin SST data are also supplied both in real-time (http://thredds.aodn.org.au/thredds/catalog/IMOS/SOOP/SOOP-ASF/VLMJ_Investigator/meteorological_sst_observations/catalog.html) and in delayed mode after reprocessing (e.g., http://thredds.aodn.org.au/thredds/catalog/IMOS/SOOP/SOOP-ASF/VLMJ_Investigator/meteorological_sst_observations/2016/ISAR-QC/catalog.html). These reprocessed files will be particularly valuable for satellite SST validation (as the ISAR measures SST at the same depth as measured by satellites) and are currently (2017) being used by EUMETSAT for Sentinel-3 SST validation and to JMA and Oceans University China for Himawari-8 SST validation. Further information can be found in the data and documentation links below.

This record describes the End of Voyage (EOV) archive from the Marine National Facility (MNF) RV Investigator research voyage in2018_v03, titled "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27oS." The voyage took place from Brisbane (QLD) to Brisbane between April 19 and May 10, 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, 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 and Ozone sensors, Weather Radar, Greenhouse Gas Analysers (Picarro), Air Pressure, Wind Speed and Direction sensors, Photosynthetically Active Radiation (PAR) sensor, Infrared Sea Surface Temperature Autonomous Radiometer (ISAR), Seawater (TSG, fluorometer, optode), Thermosalinographs, CTD, Hydrochemistry. Voyage-specific measurements: Condensation Particle Counters (CPC), Cloud Condensation Nuclei counter (CCN), Triaxus, ECO Triplet, Laser Optical Particle Counter (LOPC), Submersible Ultraviolet Nitrate Analyser (SUNA). The archive for the IN2018_V03 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.