This record describes SVP data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. A total of 84 SVP casts were conducted over the duration of this voyage. Data are stored in ASCII format files with extention *.000 and *.asvp at CSIRO. 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 XBT data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. A total of 7 XBT casts were conducted over the duration of this voyage. Data are stored in netCDF files at CSIRO. 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 sub bottom profiler data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. 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 sporadically for the extent of the voyage. Data are stored in *.raw (247 files 5.39 GB) raw and *.seg (255 files 5.34 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 scientific split-beam echosounder data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. The Simrad EK60 split beam echosounders for18kHz and Simrad EK80 split beam echosounders for 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m, in the Southern Ocean Southwest of Hobart. All frequencies were logged sporadically for the extent of the voyage. The 70 KHz frequency was set to passive for the periods of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 2,644 files totalling 59.6 GB 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. Additional data products may be available on request.

This record describes multibeam echosounder data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. The Kongsberg EM710 multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter in the Southern Ocean Southwest of Hobart. The EM710 provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 70 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 110 files totalling 90.3 GB of raw data in this dataset. Sound velocity profiles were applied to this data during data acquisition. Bathymetry data contained in *.all format is corrected for motion and position. Tide corrections [were/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 further 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 multibeam echosounder data collected on the RV Investigator voyage IN2023_V04, International nutrient inter-comparison Voyage (INIV) which departed Hobart on the 05/06/23 and returned to Hobart on the 18/06/23. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, backscatter information and watercolumn backscatter in the Southern Ocean Southwest of Hobart. 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 799 files totalling 47.1 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 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 IN2023_V04, titled: "International nutrient inter-comparison study in the Southern Ocean: quantifying and identifying the causes of differences in dissolved inorganic nutrient datasets between global seagoing laboratories - Phase 2." The voyage took place between June 5, 2023 and June 18, 2023 (AEST), departing from Hobart and returning to Hobart. The OS150 unit was run for the majority part of the voyage. The OS75 was running with three beams for the duration of the voyage. Experts at University of Hawaii determined that the fourth beam is broken and will require servicing by RDI to rectify. Additionally, some electrical noise was observed, to be further investigated when returning to port. Acceptable data was obtained using the three-beam solution, with a slightly compromised range of around 600m. It is recommended that the OS75 is operated as normal for all upcoming voyages. ADCP data were collected using the University of Hawaii Data Acquisition System (UHDAS) and post-processed using the Common Ocean Data Access System (CODAS). Documentation for these systems can be found in (Hummon, 2009-2021). This dataset was processed (quality-controlled), and then archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC).

This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2023_V04, titled:"International nutrient inter-comparison study in the Southern Ocean: quantifying and identifying the causes of differences in dissolved inorganic nutrient datasets between global seagoing laboratories - Phase 2." The voyage took place between June 5, 2023 and June 18, 2023 (AEST), departing from Hobart and returning to Hobart. Hydrology samples were collected from Niskin bottles sampled at various depths during Conductivity-Temperature-Depth (CTD) deployments. Parameters analysed were salinity, dissolved oxygen, phosphate, silicate, nitrate plus nitrite and ammonium. This dataset has been processed (quality-controlled), and archived at the CSIRO National Collections and Marine Infrastructure (NCMI) 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 IN2023_V04, titled: "International nutrient inter-comparison study in the Southern Ocean: quantifying and identifying the causes of differences in dissolved inorganic nutrient datasets between global seagoing laboratories - Phase 2". The voyage took place between June 5 and June 18, 2023 departing from Hobart (TAS) and returning to Hobart. Data for 10 CTD deployments were acquired using the Sea‐Bird SBE9+V2 CTD unit #24 (S/N 1332), 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 secondary sensor had a standard deviation (SD) of 0.0010067 PSU, well within our target of ‘better than 0.002 PSU’. The standard product of 1‐decibar binned averages were produced using data from the secondary sensors. The dissolved oxygen data calibration fit had a SD of 0.92376 μM. The agreement between the CTD and bottle data was good. 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 Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2023_V04, titled:"International nutrient inter-comparison study in the Southern Ocean: quantifying and identifying the causes of differences in dissolved inorganic nutrient datasets between global seagoing laboratories - Phase 2." The voyage took place between June 5, 2023 and June 18, 2023 (AEST), departing from Hobart and returning to Hobart. 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 Temperature, 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 and other global data repositories and distributors, and made available for satellite SST validation by the Australian Bureau of Meteorology (BoM). Near real-time, unprocessed data are available via the link "Visualisation tool for Underway Data." This dataset has been processed (quality-controlled), and archived by the CSIRO National Collections and Marine Infrastructure (NCMI) Information and Data Centre (IDC). Data are available at time intervals of 5 sec (NetCDF format), 5 sec, 10 sec, 1 min and 5 min (ASCII format). Note: not all variables are quality controlled; please check for existing QC flags in the datasets. Additional information regarding this dataset is contained in the Voyage Summary and/or the Data Processing Reports for this voyage.