This record describes multibeam echosounder data collected on RV Investigator voyage IN2017_T01, Natural iron fertilisation of oceans around Australia: linking terrestrial dust and bushfires to marine biogeochemistry, which departed Sydney on the 24th September 2017 and returned to Broome on the 8th October 2017. The Kongsberg EM122 multibeam echosounder was used to acquire seafloor bathymetry, and backscatter information between Sydney and Broome. 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 at CSIRO. There are 87 files totaling 2.97 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 scientific split-beam echosounder data collected on the RV Investigator voyage IN2017_T01, Natural iron fertilisation of oceans around Australia: linking terrestrial dust and bushfires to marine biogeochemistry, which departed Sydney on the 24th September 2017 and returned to Broome on the 8th October 2017. The Simrad EK60 split beam echosounders 18, 38, 70 120, 200 and 333 kHz were used to acquire acoustic backscatter data to a range of 1500 m, from Sydney to Broome. All frequencies were logged continuously for the extent of the voyage. Data are stored in *.raw, *.bot and *.idx format at CSIRO. There are 760 *.raw files totaling 44.3 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 RV Investigator voyage IN2017_T01, Natural iron fertilisation of oceans around Australia: linking terrestrial dust and bushfires to marine biogeochemistry, which departed Sydney on the 24th September 2017 and returned to Broome on the 8th October 2017. The Kongsberg EM710 MKII multibeam echosounder was used to acquire seafloor bathymetry and backscatter information and watercolumn backscatter between Sydney and Broome. The EM710 MKII provides a 0.5° by 1° transmit and receive angular resolution respectively. The echosounder's nominal frequency range is from 40 to 100 kHz. Data are stored in *.all raw format for bathymetry and backscatter and *.wcd format for watercolumn backscatter at CSIRO. There are 348 files totalling 69.8 GB of raw *.all data and 22 files totaling 9.75GB of *wcd watercolumn 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 except for one area of interest as specified in the processing report. Processed data has 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 XBT data collected on RV Investigator voyage IN2017_T01, Natural iron fertilisation of oceans around Australia: linking terrestrial dust and bushfires to marine biogeochemistry, which departed Sydney on the 24th September 2017 and returned to Broome on the 8th October 2017 A total of 2 XBT successful casts and one unsuccessful cast 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 RV Investigator voyage IN2017_T01, Natural iron fertilisation of oceans around Australia: linking terrestrial dust and bushfires to marine biogeochemistry, which departed Sydney on the 24th September 2017 and returned to Broome on the 8th October 2017. 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 during the voyage. Data are stored in *.raw (21 files 1.45 GB) raw and *.seg (20 files 1.42 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 Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2021_V03, titled "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27S." The voyage took place between May 8 and June 3, 2021 departing from Hobart (TAS) and arriving in Brisbane (QLD). Nutrient samples were analysed using segmented flow SEAL AA3 and results are in µmol/L. In-house methods SOP 001, SOP 002, SOP 003 and SOP 004 were used to analyse nutrients. Please cite the following paper when using Hydrochemistry data for silicate, phosphate, nitrate+nitrite (NOx) and nitrite analysis: Rees, C., L. Pender, K. Sherrin, C. Schwanger, P. Hughes, S. Tibben, A. Marouchos, and M. Rayner. 2018. Methods for reproducible shipboard SFA nutrient measurement using RMNS and automated data processing. Limnol. Oceanogr: Methods Doi:10.1002/Iom3.10294 Salinities were analysed using Guildline 8400B Autosal Lab Salinometer and OSIL software. The salinometer was calibrated with IAPSO standard seawater P163 and P164. In-house method SOP 006 was used to analyse salinity, units are Practical Salinity Unit (PSU). Dissolved Oxygens were analysed using Scripps UV titrator and software, units measured in ml/L and converted to µmol/L. Dissolved oxygen was analysed using in-house method SOP 005. All data was processed with HyPro 5.7 on the ship and any data re-processed on shore was with HyPro 5.7. A copy of HyPro is available with the data. Nutrient data decimal places within the CSV file; silicate is 1 decimal place, nitrite is 3 decimal places and NOx (nitrate + nitrite), phosphate and ammonium is 2 decimal places. Previously values below detection limit were set to zero these values are now displayed as the measured value even if that is a negative value. Oxygen Data is displayed to 3 decimal places. Salinity data is displayed to 4 decimal places, prior to in2018_t01 voyage it was 3 decimal places in the csv file. Data processing notes are in the process report (in2021_v03_HYD_ProcessingReport.pdf). This dataset has been 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 Hydrology (HYD) data collected from the Marine National Facility (MNF) RV Investigator voyage IN2024_V03, titled: "Untangling the causes of change over 25 years in the southeast marine ecosystem - Voyage 2." The voyage took place between May 1 and May 31, 2024, departing from Hobart (TAS) and arriving in Sydney (NSW) 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 Underway (UWY) data collected from the Marine National Facility (MNF) RV Investigator Voyage IN2017_T01, titled: "Natural iron fertilisation of oceans around Australia: linking terrestrial dust and bushfires to marine biogeochemistry." The voyage took place between September 24 and October 8, 2017 departing from Sydney (NSW) and arriving in Broome (WA). 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 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.