This record describes Nutrient data collected from the Marine National Facility (MNF) RV Investigator voyage IN2019_V05, titled: "Integrated Marine Observing System: monitoring of East Australian Current property transports at 27°S". The voyage took place between September 9 and September 29, 2019 departing from Brisbane (QLD) and arriving in Brisbane.
The primary objective of the voyage was to recover and re-deploy an array of six full depth current meter and property (temperature, salinity and pressure) moorings from the continental slope to the abyssal waters off Brisbane (27°S). The East Australian Current (EAC) mooring array is a component of Integrated Marine Observing System (IMOS) and is used to capture the mean and time varying flow off the EAC.
The secondary objective was to collect and identify larval fish species in different water masses and frontal eddies to gain an understanding of their growth and mortality rates.
For continual underway nutrient measurements, the AA100 was setup in the Underway Laboratory. The AA100 measured Nitrate and Phosphate off the instrument clean seawater intake of RV Investigator. Over the course of the voyage 5514 data points were measured by the AA100. The underway measurements were made continually, but due to the nature of method and data processing this results in a calibrated data point every 108 seconds.
All the data included in the final dataset is to be considered as good data. The dataset has had a reasonable level of quality control applied to ensure there are no apparent erroneous data points.
The matched latitude and longitude coordinates supplied in the dataset were obtained from the ships underway computing systems. Nutrient analysis data points were matched using UTC time stamps, no time correction was applied to account for the residence time in the ships piping or in the instrument, meaning all data is offset by 7:35 (minutes: seconds). If extremely accurate latitude and longitude values are required, a time correction will need to be applied and the ship position values realigned.
The final dataset includes latitude, longitude, UTC time stamps, NO x (nitrate + nitrite in µmol l -1 ), phosphate (PO 4 in µmol l -1 ) and analysis file. The analysis file for each data point is included if correcting to the reference material used for each analysis is required. The measurements for the reference material are provided in appendix 6.2. Time stamps in the .csv data file are given in a readable format set to UTC. In the NetCDF file, the time stamps are provided as seconds since the start of 2019, i.e. 01/01/2019 00:00:00 + seconds = UTC time stamp.
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.
