This record describes Hydrology (HYD) data collected from the Marine National Facility (MNF) 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 between September 11 and October 8, 2018, departing Hobart (TAS) and returning to Hobart.
The primary objective of the voyage was to characterize the sources and biogeochemical cycling of iron and associated nutrients and their impact on productivity southwest, southeast and northeast of Tasmania. Hydrochemistry analysed salinity, oxygen and nutrient samples collected from the conductivity temperature depth (CTD) rosette, trace metal rosette (TMR), underway (UWY) seawater supply and experiments (EXP) conducted on board. Underway nitrate plus nitrite (NOx) and phosphate was analysed continuously using the AA100 nutrient analyser while transiting between stations. The AA100 was connected to the underway seawater supply surface water (7 m) in the underway lab. Please refer to the separate report for the data processing of the AA100 data. Five nutrients were analysed; silicate, phosphate, nitrate + nitrite, nitrite and ammonium. Certified reference materials for nutrients in seawater were analysed within each analytical run. The reference materials were within GO-SHIP specified limits.
This dataset has been archived at the CSIRO O&A Information and Data Centre (IDC) in Hobart.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 data was collected by participants on the Marine National Facility (MNF) RV Investigator voyage IN2018_V04.
The data was processed by Christine Rees & Stephen Tibben (CSIRO O&A).
Data archived by Andres Roubicek (CSIRO O&A).
Data source: original field data.
High quality data was produced for salinity and dissolved oxygen analyses and were also within specified limits of quality control. Salinities were analysed using Guildline 8400B Autosal Lab Salinometer and OSIL software. The salinometer was calibrated with IAPSO standard seawater P162. 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. 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 (in2018_v04_HYD_ProcessingReport.pdf).