Gross Primary Production of Antarctic Landfast Sea Ice: A Model-Based Estimate These are the input and outputs containing gross primary production of Antarctic landfast sea ice (fast ice) data used in the paper " Gross Primary Production of Antarctic Landfast Sea Ice: A Model-Based Estimate" by Wongpan et al. There are required inputs and processed outputs from the 1-dimensional Louvain-la-Neuve Sea Ice Model (LIM1D). The model was configured to model Antarctic fast ice, assumed to form in situ with its spatial distribution prescribed from the recent satellite-derived fast ice product of Fraser et al. (2020), with an initial thickness of 0.05 m (Wongpan et al., 2021), and evolving with a 1–h time step. LIM1D represents the ice column as ten layers with equal thickness plus one additional snow layer. Four categories of physical processes are implemented: sea-ice growth and melt, thermal diffusion, brine dynamics, and radiative transfer. Photosynthesis was limited by light and macro-nutrient availability, temperature, and brine salinity. A full description of LIM1D is given in Vancoppenolle et al. (2010), Moreau et al. (2015) and Vancoppenolle and Tedesco (2016). We followed initialization and parameterizations as described in Lim et al. (2019) suggesting that ice algae (represented as diatoms) have higher silicate half-saturation constants (KSi) than pelagic diatom species. The model can be downloaded from http://forge.ipsl.jussieu.fr/lim1d revision #3.26. The Japanese 55-year atmospheric reanalysis product for driving ocean-sea ice models (JRA55-do; Tsujino et al., 2018) was used as surface forcing, selected because of its high resolution and development for forcing ocean and sea-ice models of the Ocean Model Intercomparison Project phase 2 (OMIP-2; Tsujino et al., 2020). To avoid truncation of extremely low air temperatures applied in JRA55-do around the Antarctic coast as a function of time and latitude(Large and Yeager, 2004; Tsujino et al., 2018), JRA55-do temperatures were replaced with data from the fifth-generation European Centre for Medium-Range Weather Forecasts re-analysis (ERA5; Hersbach et al., 2018). A simulation (JRATEMP, Table 1) was also performed using the JRA55-do temperatures, despite their unrealistic truncation described above. For 2005-2006, fast-ice pixels at a native resolution of 1 km from the satellite-based dataset of Fraser et al. (2020) were distributed into 1690 grid cells, matching JRA55-do’s 0.5625° grid. The details for each run are CONTROL = RUN006 For all runs, each grid cell is divided into nine equal-area snow depth categories. For each category, snowfall is multiplied by a log-normally distributed, category-specific factor (0.102, 0.272, 0.427, 0.532, 0.721, 0.952, 1.310, 1.740, 3.310), in order to approach a log-normal snow depth distribution (see Table 1 in Saenz and Arrigo, 2014). Finally, primary production in the grid cell is the average of the nine equal-area productivities calculated with different snow depths. This experiment is considered the most realistic approach and is named CONTROL; OHF = RUN004 This run used an oceanic heat flux of 30 W m–2 during summer which was derived from observations at Davis Station (Swadling, 1998). KSI = RUN005 An experiment to test the effect of modified silicate half-saturation constants (KSI) from KSi = 50 μM in the CONTROL experiment (after Lim et al., 2019) to KSi = 3.9 μM in 176 the KSI experiment (after Sarthou et al., 2005). OHF_KSI = RUN007 Combining OHF and KSI changed as above. JRASNOW = RUN009 This run includes a prescribed subgrid scale snow thickness distribution, as CONTROL but using snow input directly from JRA55-do. JRATEMP = RUN010 This run uses the JRA55-do temperatures NOSUB = RUN006 without sub-grid-scale snow Spatially-uniform snow cover increasing linearly throughout the year at a rate of 0.29 m y–1 (as with CONTROL), but without subgrid-scale snow thickness distribution. The folder tree is ├── INPUT │ ├── RUN004 │ ├── RUN005

The Sub-Antarctic Zone (SAZ) in the Southern Ocean provides a significant sink for atmospheric CO2 and quantification of this sink is therefore important in models of climate change. During the SAZ-Sense (Sub-Antarctic Sensitivity to Environmental Change) survey conducted during austral summer 2007, we examined CO2 sequestration through measurement of gross primary production rates using 14C. Sampling was conducted in the SAZ to the south-west and south-east of Tasmania, and in the Polar Frontal Zone (PFZ) directly south of Tasmania. Despite higher chlorophyll biomass off the south-east of Tasmania, production measurements were similar to the south-west with rates of 986.2 plus or minus 500.4 and 1304.3 plus or minus 300.1 mg C m-2 d-1, respectively. Assimilation numbers suggested the onset of cell senescence by the time of sampling in the south-east, with healthy phytoplankton populations to the south-west sampled three week earlier. Production in the PFZ (475.4 plus or minus 168.7 mg C m-2 d-1) was lower than the SAZ, though not significantly. The PFZ was characterised by a defined deep chlorophyll maximum near the euphotic depth (75 m) with low production due to significant light limitation. A healthy and less light-limited phytoplankton population occupied the mixed layer of the PFZ, allowing more notable production there despite lower chlorophyll. A hypothesis that iron availability would enhance gross primary production in the SAZ was not supported due to the seasonal effect that masked possible responses. However, highest production (2572.5 mg C m-2 d-1) was measured nearby in the Sub-Tropical Zone off south-east Tasmania in a region where iron was likely to be non-limiting (Bowie et al., 2009). Table 1:Gross primary production at each CTD station and associated data; Mixed layer depth (Zm, m), incoming PAR (mol m-2 d-1), vertical light attenuation (Kd, m-1), euphotic depth (Zeu, m), differences between euphotic depth and mixed layer depth (Zeu-Zm, m), column-integrated chlorophyll a (0 to 150 m, mg m-2), column-integrated production (0 to 150 m, mg C m-2 d-1), production within the mixed layer (mg C m-2 d-1), production below the mixed layer (mg C m-2 d-1), production within the euphotic zone (1% PAR, mg C m-2 d-1), production below the euphotic zone (mg C m-2 d-1). Kd values that were calculated from chlorophyll a v PAR regressions are marked with an asterisk. At some stations there was a surface mixed layer as well as a secondary mixed layer and both depths are indicated. Table 2:Photosynthetic attributes of phytoplankton with depth at each CTD station; Mixed layer depth (m), euphotic depth (Zeu, m), maximum photosynthetic rate [Pmax, mg C (mg chl a)-1 h-1], maximum photosynthetic rate corrected for photoinhibition [Pmaxb, mg C (mg chl a)-1 h-1], initial slope of the light-limited section of the P-I curve [alpha, mg C (mg chl a)-1 h-1 (micro-mol m-2 s-1)-1], rate of photoinhibition [beta, mg C (mg chl a)-1 h-1 (micro-mol m-2 s-1)-1], intercept of the P-I curve with the carbon uptake axis [c, mg C (mg chl a)-1 h-1], light intensity at which carbon-uptake became saturated (Ek, micro-mol m-2 s-1), and chlorophyll a measured using HPLC (mg m-3).

Sea-ice cores (0.09 m internal diameter) were sampled during Polarstern voyage PS117 to the Weddell Sea during December 2018 to January 2019. Ice core measurements include position, snow thickness, ice thickness, ice core temperature and bulk-salinity profiles, macro-nutrient concentrations as well as Chlorophyll-a pigment content. In addition on each ice station downwelling (surface) and under-ice irradiances were measured with a hyperspectral radiometer.

The distribution and abundance of ice-associated copepods in the fast ice of the Australian Antarctic Territory were investigated over a distance of approximately 650 km between October and December 1995. The six sites where collections were made were: offshore from Mawson station, Larsemann Hills (including Nella Bay), Rauer Islands (ice edge near Filla Is), O'Gorman Rocks and Bluff Island near Davis Station, and Murphy Rocks in the northern Vestfold Hills. Ice cores were obtained using SIPRE ice augers. Five to ten cores were collected along transects several km in length. Thickness of sea ice and snow cover were measured at each sampling site. Chlorophyll a concentrations were determined for each core. Copepods were isolated from the melted core water and identified and counted. Zooplankton tows were also made at each site where cores were collected. Nine species of copepods were identified from the cores. However, of these, only three were recorded regularly: Paralabidocera antarctica, Drescheriella glacialis and Stephos longipes. The abundance of copepods ranged between 0 and 147/L. The highest densities were recorded at the Larsemann Hills and the lowest at Murphy Rocks. Within the cores, the highest abundances were found in the bottom 10 cm of ice, irrespective of the species. Chlorophyll a concentrations ranged between 0.9 and 373 mg/m3. Data available: excel files containing sampling dates, sampling sites and abundances (number per L) of three dominant sea ice copepods, Paralabidocera antarctica, Drescheriella glacialis, Stephos longipes. Data are presented for developmental stages (nauplii, copepodites and adults) where available. Totals are also provided. Vertical distribution in some cores is also provided. Chlorophyll a concentrations (ug/L) provided for most sites. Detailed information about each of the spreadsheets is provided below: The chlorophyll spreadsheet shows chlorophyll concentrations for 5 sites in the AAT. The column headings are: core - reference number of the core collected subsection - depth in the core in cm volume - vol of melted core water volume added - 1 L of filtered seawater for melting % original - amount of total that core water represents (i.e. minus the 1L added) aliquot - volume subsampled for chlorophyll analysis acetone - amount added (mL) for extraction 750, 664, 647, 630 - wavelengths where absorbance was measured chloro a - amount of chlorophyll a in the sample ug/L - chloro a expressed as a concentration The spatial spreadsheet shows species abundances of three copepods at 4 sites N1 to NVI - nauplius stage 1 to 6 of a species CI to CVI - copepodite stage 1 to 6 of a species F or M - female or male of copepodite stage 5 or 6 1,1 etc - cores 1 and 2 from site 1 within a major location (e.g. 2 cores close together in the Larsemann Hills) The temporal spreadsheet shows abundances over time at 2 sites (O'Gorman Rocks, Bluff Is) near Davis and two species (Paralabidocera antarctica and Drescheriella glacialis) on several sampling dates N1 to N3 - total nauplii in each of three cores (i.e. not separated into stages as above) C1 to C3 - total copepodites A1 to A3 - total adults Then at the bottom are the means of each three cores.

As part of Australian Antarctic Science project # 4298 and Antarctica New Zealand project K131A, a total number of 24 sea ice sites were sampled for bio-optical measurements along 2 transects on land-fast sea ice in McMurdo Sound (Antarctica) during November 2014. Measurements included hyperspectral surface irradiance measurements (TriOS ASS) as well as under-ice radiance measurements using a TriOS ARC (350 – 900 nm, 3.3 nm resolution) radiometer mounted to an L-arm. After completion of radiometric measurements, snow thickness was measured with a ruler and an ice core was collected directly above the radiometer location. Sea-ice freeboard (tape measure) and ice thickness (ice core length) were recorded. Ice core (9 cm internal diameter) bottom sections (lowermost 0.1 m of ice cores) were collected and were used for determination of algal pigment content (using HPLC) and spectral ice algal absorption coefficients (ap, ad, aph). Sea ice physical properties including vertical profiles of ice temperature and salinity profiles were collected at some specific locations along the transects, which were sampled near Little Razorback Island and near Cape Evans, McMurdo Sound.

Metadata record for data expected from ASAC Project 2767 See the link below for public details on this project. A multidisciplinary survey of the processes linking sea ice with biological elements of Antarctic marine ecosystems was conducted in winter 2007. The survey provided large-scale information on sea ice biological and physical parameters in the 100-130 degree East sector off East Antarctica. The distribution of sea ice algae and krill were measured using various methods including ice coring surveys and trawls. These measurements were complemented by shipborne measurements and an intensive sea ice sampling program. Use of an ROV was attempted but did not result in quantitative/geo-referenced data. Under-ice video files are available from the Chief-Investigator. Individual word documents are available from this metadata record for each ice station. These contain information on the ice station number, date and time of record and the parameters/ samples.

This dataset (provided as a series of CF-compatible netcdf file) consists of 432 consecutive maps of Antarctic landfast sea ice, derived from NASA MODIS imagery. There are 24 maps per year, spanning the 18 year period from March 2000 to Feb 2018. The data are provided in a polar stereographic projection with a latitude of true scale at 70 S (i.e., to maintain compatibility with the NSIDC polar stereographic projection).

The data comprise images (encapsulated postscript and PNG formats) showing the integrated solar irradiance exposure of sea ice. The exposure value for ice at a given grid point was calculated by computing the motion trajectory of that patch of ice across the autumn/winter season (1-March to 1-November). Daily motion data were obtained from the National Snow and Ice Data Center (http://nsidc.org/data/nsidc-0116.html). The integrated radiation exposure was then calculated using daily estimates of downward solar flux from the NCEP/NCAR re-analyses. The values shown in the images are cumulative photosynthetically active radiation expressed in W-days/m^2. Please contact the data custodian before using these data. This work was done as part of ASAC project 2943 (ASAC_2943). See the link below for public details about the project.

The dataset lists key biogeochemical parameters measured in sea ice during the SIPEX2 voyage, including dissolved and particulate iron and other trace metals, macronutrients (silicic acid, nitrates+nitrite, phosphoric acid and ammonium), iron binding organic ligands, dissolved and particulate organic carbon, Cholophylla, thermodynamics (temperature, salinity, brine volume and Rayleigh number). All sampling bottles and equipment were decontaminated using trace metal clean techniques. Care was taken at each site to select level ice with homogeneous snow thickness. At all the stations, the same sampling procedure has been used : Firstly, snow was collected using acid cleaned low density polyethylene (LDPE) shovels and transferred into acid-cleaned 3.8 l LDPE containers (Nalgene). Snow collected was analysed for temperature, salinity, nutrients, unfiltered and filtered metals. Snow thickness was recorded with a ruler. Ice cores were collected using a non-contaminating, electropolished, stainless steel sea ice corer (140 mm internal diameter, Lichtert Industry, Belgium) driven by an electric power drill. Ice cores were collected about 10 cm away from each other to minimise between-core heterogeneity. A first core was dedicated to the temperature, salinity and Chlorophyll a (Chla). To record temperature, a temperature probe (Testo, plus or minus 0.1 degrees C accuracy) was inserted in holes freshly drilled along the core every 5 to 10 cm, depending on its length. Bulk salinity was measured for melted ice sections and for brines using a YSI incorporated Model 30 conductivity meter. Chla is processed on board using a 10 AU fluorometer (turner Designs, sunnyvale California). The total length of this core is cut in sections of 7 cm. The second core is dedicated to the POC/PON (Particulate Organic Carbon/ Particulate Organic Nitrogen), DOC (Dissolved Organic Carbon) and nutrients. Six sections of 7 cm were sub-sampled from this core. The six sections were chosen so that two top, two intermediate and two basal sections. Two cores are taken for the trace metal analysis. Those cores were directly triple bagged in plastic bags (the inner one is milli-Q washed) and frozen at -20degrees C until analysis at the laboratory. Brine samples were collected by drainage from “sack holes”. Brines and under ice seawater (~1 m deep) were collected in 1 l Nalgene LDPE bottles using an insulated peristaltic pump and acid cleaned C-flex tubing (Cole Palmer). All samples were then transported to the ship as quickly as possible to prevent further freezing. Samples were used to analyse unfiltered and filtered metals, Chla, POC/PON, nutrients and DOC. Filtration for filtered metals was completed on board using a peristaltic pump and a 0.2 microns cartridge filter. All the unfiltered and filtered metals collected were acidified (2 ppt HCl seastar) and stored at room temperature until analysis at the laboratory. Nutrients, DOC and filters for POC/PON were stored frozen at -20 degrees C until analysis at Analytical Service Tasmania, Hbart. Chla filtrations and analysis were completed on board. The file "SIPEX2 sea ice data" lists key biogeochemical parameters in sea ice cores, snow, brine and underice seawater (1m depth) collected during the SIPEX2 voyage (64.26-65.15S/116.44-120.58E) carried out between the 26th of september and 29th of october 2012. The acid-cleaning protocols for sample bottles and equipment followed the guidelines of GEOTRACES (www.geotraces.org). Contamination-free ice coring equipment developed by Lannuzel et al. (2006) was used to collect ice cores. Ice cores were triple bagged and stored at -18 degrees C until further processing in the home laboratory. Ice cores were then sectioned under a class-100 laminar flow hood (AirClean 600 PCR workstation, AirClean System) using a medical grade stainless steel bonesaw (Richards Medical), thouroughly rinsed with ultra-high purity water (18.2 MO), and ice sections were then allowed to melt at ambient