Overview of the project and objectives: To investigate whether nitrate uptake and processes other than nitrate uptake by phytoplankton are significant and show spatial variability possibly induced by varying availability of Fe and other parameters in the region, seawater was collected from CTD (Conductivity, Temperature and Depth) and TMR (Trace Metals Rosette) casts jointly with the nutrient sampling, as well as well as sea-ice collected from Bio ice-core types on Ice Station, for analysis of nitrate d15N, d18O isotopic composition. Results have been interpreted in the light of prevailing nitrate-nutrient concentrations (Belgian team) and N-uptake regimes for the Ice Stations (new vs. regenerated production and nitrification; see Silicon, Carbon and Nitrogen in-situ incubation Metadata file). Methodology and sampling strategy: Samples for isotopic composition of nitrate were collected from the CTD rosette, TMR and Bio ice-core jointly with the nutrient sampling. Sea-ice sampling: sampling strategy follows ice stations deployment via Bio ice-core type. Most of the time we worked close to / directly on the Trace Metal site following precautions concerning TM sampling (clean suits etc.). When we worked close to the TM site, precautions were not such important because we don't need the same drastic precautions for our own sampling. We work together because we want to propose a set of data which helps to characterize the system of functioning in close relation with TM availability (for that, sampling location have to be as close as possible). All samples were filtered on 0.2 microns acrodiscs and kept at -20 degrees C till analysis in the home-based laboratory. We applied the denitrifier method elaborated by Sigman et al. (2001) and Casciotti et al. (2002). This method is based on the isotopic analysis of delta 15N and delta 18O of nitrous oxide (N2O) generated from nitrate by denitrifying bacteria lacking N2O-reductase activity. As a prerequisite the nitrate concentrations need to be known (nutrients analysis in the home lab.) as this sets sample amount provided to the denitrifier community. Briefly, sample nitrate is reduced by a strain of denitrifying bacteria (Pseudomonas aureofaciens) which transform nitrate into N2O, but lack the enzyme to produce N2. N2O is then analysed for N, O isotopic composition by IRMS (Delta V, Thermo) after elimination of CO2, volatile organic carbon and further cryogenic focusing of N2O (Mangion, 2011). Casciotti K.L., D.M.Sigman, M.G. Hastings, J.K. Bohlke and A. Hilkert, 2002. Measurement of the oxygen isotopic composition of nitrate in seawater and freshwater using the denitrifier method, Analytical Chemistry, 74 (19): 4905-4912. Mangion P., 2011. Biogeochemical consequences of sewage discharge on mangrove environments in East Africa, PhD Thesis, Vrije Universiteit Brussel, 208 pp. Sigman D.M., Casciotti K.L., Andreani M., Barford C., Galanter M. and J.K. Bohlke, 2001. A bacterial method for the nitrogen isotopic analysis of nitrate in seawater and freshwater, Analytical Chemistry, 73: 4145-4153.

Overview of the project and objectives: To investigate whether the Nitrogen - Silicon - Carbon biogeochemical system functions in the Antarctic Marginal Ice Zone and shows spatial variability possibly induced by varying availability of Fe and other parameters in the region. This toolbox is part of project 4051 - samples were taken (1) on the same sea-ice site or very close than the one used for Trace Metal sampling; (2) via Trace Metal Rosette TMR; (3) via Conductivity Temperature and Depth CTD Rosette. It is also part of project 4073 since some intercalibration studies were conducted in collaboration with the primary production team. Three main tools were used which can be either independently or intricately studied. For this reason the complete set of sampling done for this stable isotope toolbox is summarized in one excel file which is duplicated and attached to three child metadata records. Same reasoning for raw data acquired on boar and on field information. This parent metadata record has thus three child metadata records. Each of the child metadata files explain individually the different approaches which were treated together by the same team to resolve the main question of sea-ice biogeochemical system functioning via the use of stable isotope ratio tools. The details of each are in the respective metadata records. The data are attached to this metadata record. METADATA FILES are: - 13C, 15N, 30Si in-situ incubation experiments during SIPEX 2 - Nitrogen and oxygen isotopic composition of nitrate during SIPEX 2 - Delta13C signal of brassicasterol and cholesterol in the Antarctic Sea-ice / Is there particulate barium in sea-ice?

Bio-optical measurements (radiometry, spectral backscatter, attenuation, absorption) for particle and phytoplankton characterisation acquired during Australian Marine National Facility RV Investigator voyage IN2016_V01. The biooptical package consisted of SeaBird 19plus CTD, Satlantic HyperOCR upwelling radiance and downwelling irradiance sensors, WetLabs ac-9, HobiLabs Hydroscat-6. At selected stations the bio-optical package was lowered to the depth of 240 m (or 20 m above the sea bottom if the depth was lower than 260 m) at 20 m/minute. The radiometric measurements were taken only during the day. Parameters measured: SeaBird CTD (4 Hz frequency): - Temperature - Salinity - Pressure - PAR - Fluorescence - Oxygen Satlantic HyperOCR: - Upwelling radiance (Lu) - spectral - Downwelling irradiance (Ed) – spectral - Pressure HobiLabs Hydroscat: - Backscattering coefficient at 6 wavelengths (442, 488, 550, 589, 676, 850 nm) - Fluorescence (550, 676 nm) - Pressure WetLabs ac-9 (2 Hz frequency) - Light absorption coefficient at 9 wavelengths (412, 440, 488, 510, 532, 555, 650, 676, 715 nm) - Light attenuation coefficient at 9 wavelengths (412, 440, 488, 510, 532, 555, 650, 676, 715 nm) At some stations transmissometer data at 650 nm using the Wetlabs c-Star were collected. Data type product(s) created: raw and calibrated data files were created on board, processed and quality controlled files (.dat and/or .csv) will be available by the end of 2016. Owner of instrument: CSIRO Units: CTD data: units given in the header Hydroscat data: bbp_HEOBI_all: all bbp in m^-1, slope unitless Calibrated: depth in m, all bb in m^-1,all betabb sr^-1 m^-1 Radiometers: all Ed uW/cm^2/nm All Lu uW/cm^2/nm/sr Depth is always given in meters. See the metadata file in the download for more information.

Oceanographic measurements were collected aboard Aurora Australis cruise au1603, voyage 3 2015/2016, from 11th January to ~24th February 2016. The cruise commenced with the K-AXIS project, the major marine science component of the cruise. This was the Australian component (P.I.’s Andrew Constable, Steve Rintoul and others) of a combined biological and oceanographic study in the vicinity of the Kerguelen Axis. After conclusion of marine science work the ship went to Mawson for a resupply. During a storm on 24th February the ship broke free of its mooring lines and ran aground on the rocks at West Arm in Horseshoe Harbour, thus ending the cruise. Expeditioners were eventually taken to Casey on the Shirase, then flown home. Meanwhile the Aurora Australis was refloated and sailed to Fremantle, then on to Singapore for repairs. This report discusses the oceanographic data from CTD operations on the cruise. A total of 47 CTD vertical profile stations were taken on the cruise (Table 1). Over 850 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite and silicate), dissolved inorganic carbon (i.e. TCO2), alkalinity, POC and PN, and biological parameters, using a 24 bottle rosette sampler. A UVP particle counter/camera system was attached to the CTD package (P.I. Emmanuel Laurenceau). A separate trace metal rosette system was deployed from the trawl deck (P.I. Andrew Bowie). Upper water column current profile data were collected by a ship mounted ADCP, and meteorological and water property data were collected by the array of ship's underway sensors. Eight drifting floats were deployed over the course of the cruise. Processing/calibration and data quality for the main CTD data are described in this report. Underway sea surface temperature and salinity data are compared to near surface CTD data. CTD station positions are shown in Figure 1, while CTD station information is summarised in Table 1. Float deployments (5 x Argo/Apex, 2 x SOCCOM and 1 x Provor) are summarised in Table 10. Further cruise itinerary/summary details can be found in the voyage leader report (Australian Antarctic Division unpublished report: Voyage 3 2015-2016, RSV Aurora Australis, Voyage Leader’s report - see the metadata record "Aurora Australis Voyage 3 2015/16 Track and Underway Data" for access to the Voyage Report).

Oceanographic measurements were collected aboard Aurora Australis cruise au1203, voyage 3 2011/2012, from 5th January to 12th February 2012. The cruise commenced with opportunistic CTD's in the region of the Adelie Depression and the former Mertz Glacier ice tongue, followed by a full south to north occupation of the CLIVAR/WOCE meridional section I9S. A total of 95 CTD vertical profile stations were taken on the cruise, most to within 15 metres of the bottom. Over 1500 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite and silicate), dissolved inorganic carbon (i.e. TCO2), alkalinity, pH, barium (dissolved), and biological parameters, using a 24 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package, while upper water column current profile data were collected by a ship mounted ADCP. Meteorological and water property data were collected by the array of ship's underway sensors. An array of 5 current meter moorings was recovered from the Antarctic continental slope at the south end of the I9S transect.

Oceanographic measurements were conducted on and around the Antarctic shelf in the vicinity of the Mertz Glacier during the southern summer of 2007/2008, on Aurora Australis voyage au0803, V3 2007/2008. Data were collected as part of the CASO (oceanography) and CEAMARC (fishing) programs. The CASO program included occupation of the southern portion of the SR3 transect, plus additional transects down the slope. A total of (130) CTD vertical profile stations were taken, most to within 15 m of the bottom. Over (1400) Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients, CFCs, dissolved inorganic carbon, alkalinity, oxygen-18, germanium, and biological parameters, using a 24 bottle rosette sampler. Full depth current profiles were collected by a lowered acoustic Doppler profiler (LADCP) attached to the rosette package, while near surface current data were collected by a ship mounted ADCP. Additional CTD profiles were taken at 2 subantarctic sites on the transit south. An array of 4 current meter and thermosalinograph moorings were deployed across a basin outflowing from the Mertz Polynya region.

Oceanographic measurements were collected aboard RV Investigator cruise in1801 (CSIRO voyage designation in2018_v01) from 11th January to 22nd February 2018, along CLIVAR Southern Ocean repeat meridional section SR3, followed by Adelie land shelf stations, small meridional sections along 150E (the south end of CLIVAR section P11S) and 132E, and several stations along CLIVAR zonal section S4. A total of 108 CTD vertical profile stations were taken on the cruise, most to within 14 metres of the bottom. Over 2800 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, silicate, ammonia and nitrite), CFC's plus tracers (CFC-11, CFC-12, SF6 and N2O), dissolved inorganic carbon (i.e. TCO2), alkalinity, pH, C13/C14, genomics, HPLC, POC, chlorophyll, radiogenic isotopes, helium, ice nucleation, and Ca/Mg, using a 36 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package. Upper water column current profile data were collected by a ship mounted ADCP (75 kHz). Trace metal rosette and in situ pump deployments were done at some of the CTD stations. Meteorological and water property data were collected by the array of ship's underway sensors. A large assortment of 29 drifting floats was deployed throughout the cruise. A detailed data report is included with the data set, with summary of all CTD data and important data quality information. The data set contains CTD 2dbar averaged data, and Niskin bottle data (core hydrochemistry of salinity, dissolved oxygen and nutrients, plus CFC-11, CFC-12, SF6 and N2O), in text and matlab formats. A WOCE (CCHDO) 'exchange' format version of the data is also available from the CCHDO data centre.

Oceanographic measurements were collected aboard Aurora Australis cruise au1602, voyage 2 2016/2017, from 8th December 2016 to 21st January 2017. The cruise commenced with a Casey resupply, followed by work around the Dalton Polynya/Moscow University Iceshelf, then the Mertz Glacier region, and then around the Ninnis Polynya. 14 stations at the southern end of the SR3 transect were also completed. Ice conditions prevented access to the front of the Totten Glacier. A total of 73 CTD vertical profile stations were taken on the cruise, most to within 12 metres of the bottom (Table 1). Over 800 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, silicate, ammonia and nitrite), dissolved inorganic carbon (i.e. TCO2), alkalinity, Th-234, POC, Chla, PAM, HPLC, Nd, Po-210/Pb-210, bacteria, O-18, caesium, and Teflon pollutants, using a 24 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package. Upper water column current profile data were collected by a ship mounted ADCP. Meteorological and water property data were collected by the array of ship's underway sensors. 8 Argo floats were also deployed (Table 13) on the transit from Hobart to Casey. The data set contains CTD dbar data and Niskin bottle data (i.e. core hydrochemistry only - salinity, dissolved oxygen and nutrients). A detailed data report is included, with a description of the data and important data quality information.

Oceanographic measurements were collected aboard RV Investigator cruise in1805 (CSIRO voyage designation in2018_v05) from 16th October to 16th November 2018, along a number of transects across a standing meander of the Antarctic Circumpolar Current between 148o and 156oE. A total of 77 CTD vertical profile stations were taken on the cruise, most to within 12 metres of the bottom. Over 1900 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite, silicate, ammonium and nitrite), chlorophyll, POC and DOC, and for incubation experiments, using a 36 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package. Upper water column current profile data were collected by a ship mounted ADCP (75 kHz and 150 kHz). Data coverage was increased by additional transects towing a Triaxus towed CTD system. A microstructure profiler was deployed at many of the CTD stations. Meteorological and water property data were collected by the array of ship's underway sensors. An oceanographic mooring was deployed at 55o 32.544’S , 150o 52.332’E, and a series of floats and drifters were deployed. Bathymetry was collected by the ship’s multibeam system. The data set contains CTD 2dbar averaged data, and Niskin bottle data (core hydrochemistry of salinity, dissolved oxygen and nutrients), in text and matlab formats, and a full data report. A WOCE (CCHDO) 'exchange' format version of the data is also available on request.

Data collected from O'Gorman rocks near Davis Station between February 2004 to January 2005. Data were collected using a Yellow Science Industries 6600 Sonde. Vertical profiles of Temperature, Salinity, Conductivity, Dissolved Oxygen, Photosynthetically Active Radiation were collected. Each Sampling date/time and depths were recorded. The data are stored in spreadsheet form, and saved as a comma separated values text file. This work was carried out as part of ASAC project 40. The fields in this dataset are: Date Time Temperature Conductivity Salinity Dissolved Oxygen Depth Photosynthetically Active Radiation