Environmental descriptors that are available for the study area (-180 degrees W/+180 degrees E; -45 degrees/-78 degrees S) and for the following periods: 1955-1964, 1965-1974, 1975-1984, 1985-1994, 1995-2012. They were compiled from different sources and transformed to the same grid resolution of 0.1 degree pixel. We also provide future projections for environmental descriptors established based on the Bio-Orable database (Tyberghein et al. 2012). They come from IPCC scenarii (B1, AIB, A2) for years 2100 and 2200 (IPCC, 4th report).

Overview of the project and objectives: Assessing the contribution of the different N substrates to the primary production process, such as the biogenic silica production and dissolution in the Antarctic sea-ice provides a means to understand the biogeochemical system functioning. In such a semi closed-type system, assess incorporation rates of HCO3-, NO3-, NH4+, SiOH4, BSi dissolution, nitrification, C-release in close-by ice-cores (3 ice-cores dedicated to (i) 13C-assimilation + 15NH4+ uptake rate, (ii) 13C-assimilation + 15NO3- uptake rate and nitrification, (iii) Biogenic silica production and dissolution via 30Si isotope tool) will allow improving the knowledge of system functioning. This is also closely linked to the thematic of iron availability since these experiments are done close to / on the Trace Metal site allowing us to hopefully propose a relatively complete image of biogeochemical activity and relationship with trace metals on this site. Methodology and sampling strategy: 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). 14C and 13C-incubation experiment intercalibration work were conducted on the Biosite (different place than TM site except for station 7) Incubation experiment samples are analyzed via (1) Elemental Analyzer - Isotope Ratio Mass Spectrometer (EA-IRMS) for carbon and nitrogen (VUB, Brussels, Belgium); (2) High Resolution Inductively Coupled Mass Spectrometer (HR-ICPMS) for silicon (RMCA, Brussels, Belgium).

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?

This is the CTD and Niskin bottle data set from the RV Tangaroa cruise tan0704, 7th Mar 2007 to 29th Mar 2007, along the Macquarie Ridge. This was the deployment cruise for the Macquarie Ridge mooring array. Dissolved oxygen data have been removed from this data set (oxygen bottle data never analysed). There were a total of 75 CTD casts on this cruise.

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 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.

Taken from the accompanying report: Oceanographic measurements were collected aboard the Aurora Australis on cruise au0806 (voyage 6 2007/2008, 22nd March 2008 to 17th April 2008). This cruise completed the CASO oceanographic program begun on the CEAMARC cruise (au0803, voyage 3 2007/2008), with a full occupation of the SR3 transect between Antarctica and Tasmania. CASO program objectives were: 1. to measure changes in water mass properties and inventories throughout the full ocean depth between Australia and Antarctica along 140oE (the CLIVAR/WOCE repeat section SR3), as part of a multi-national International Polar Year program to obtain a circumpolar snapshot of the Southern Ocean in austral summer 2007-8; 2. to estimate the transport of mass, heat and other properties south of Australia, and to compare results to previous occupations of the SR3 line and other sections in the Australian sector; 3. to deploy moorings near the Adelie Depression (142-145oE) as part of a joint Australia-France-Italy program to monitor changes in the properties and flow of Adelie Land Bottom Water; 4. to identify mechanisms responsible for variability in ocean climate south of Australia. The CASO program (with a full occupation of the SR3 transect) was originally scheduled for a single cruise. The shipping schedule was re-arranged following an unexpected period in drydock, due to a problem with the ship's thrusters, and as a result the CASO program was split over the two cruises. Several of the southern stations occupied on the first cruise au0803 were repeated on the second cruise au0806, to minimise the impact on the data set of the time gap between the cruises. A total of 131 CTD vertical profile stations were taken on au0803, and 73 CTD station were taken on au0806, most to within 20 metres of the bottom. During the 2 cruises, over 2900 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite and silicate), 18O, CFC's, dissolved inorganic carbon, alkalinity, 14C, dissolved organic carbon, density (i.e. analysis of the effect of water composition on water density), germanium/silica/boron isotopes, trace metals, neodymium, chlorophyll-a, cell counts, pigments, genetic analyses, and other 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. Data were also collected by the array of ship's underway sensors. This report describes the processing/calibration of the CTD data, and details the data quality. An offset correction is derived for the underway sea surface temperature and salinity data, by comparison with near surface CTD data. CTD station positions are shown in Figures 1 and 2, while CTD station information is summarised in Table 1. Mooring and drifter deployments/recoveries are summarised in Table 14. Mooring data from the Adelie Depression deployments are discussed in the mooring data reports Rosenberg (unpublished report, 2009) and Meijers (unpublished report, 2009). Further cruise itinerary/summary details can be found in the voyage leader reports (Australian Antarctic Division unpublished reports: Riddle, V3 2007/08 VL report; Rintoul, V6 2007/08 VL report). Hydrochemistry and CFC cruise reports are in Appendix 1 and Appendix 2. Details about the data are available in a readme file and a full report in the download file.

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.

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.