A times series of data was collected from coastal (land-fast) sea ice at Davis Station, Eastern Antarctica (68 degrees 34' 36" S, 77 degrees 58' 03" E; Figure 1) from November 16 to December 2, 2015. Sea ice temperature and salinity, as well as macro-nutrients (nitrate NO3-, nitrite NO2-, ammonium NH4+, phosphate PO43- and DSi), particulate organic carbon (POC) and chlorophyll a (Chla) in the sea ice were measured six times in 16 days of austral spring and early summer (Nov. 16, Nov. 20, Nov. 23, Nov. 26, Nov. 29, and Dec. 2; in days of the year, 320, 325, 327, 330, 333, and 336). Depths were measured from the top of the ice cores. Seawater below the ice was also sampled for comparison. Samples of snow, sea ice, brine and under-ice seawater were collected under trace metal clean conditions near Davis station during the transition of sea ice from winter to spring conditions (October 2015), on a regular basis (every 4 days) for 3 weeks. 6 sampling events were successfully achieved. The list of parameters collected during the fast ice study include in situ temperature, ice texture, pH, oxygen, iron and Chla, Br/I, carbonate, nutrients and POC, incubations with stable N and C isotopes. Samples are currently returning on V3 and will be analysed in the US, Belgium and Australia in the coming months. The biogeochemical observations will allow us to determine the roles of light versus iron in the initiation of the spring bloom in this region, and the role of the melting fast ice in fertilising the spring time primary production.

Metadata record for data from AAS (ASAC) project 3026. Public This project will assess the importance of the trace micro-nutrient element iron to Antarctic sea-ice algal communities during the International Polar Year (2007-2009). We will investigate the biogeochemistry of iron, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the the influence of organic exopolysaccharides on iron solubility, complexation and bioavailability, both within the ice and in surrounding snow and surface seawater. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Project objectives: This project will assess the importance of the trace element iron (Fe) as a micro-nutrient to seasonal sea-ice algal communities in the Australian sector of Antarctica during the International Polar Year (2007-09). We will investigate the biogeochemistry of Fe, including a comprehensive examination of its distribution, speciation, cycling and role in fuelling ice-edge phytoplankton blooms. A significant part of this research will concentrate on the influence of organic exopolysaccharides (EPS) on Fe solubility and complexation (and hence bioavailability), both within the ice and in surrounding surface waters. This innovative research will improve our understanding of key processes that control the productivity of the climatically-important Antarctic sea-ice zone. Specifically, in this project: - The biogeochemical behaviour of Fe in sea-ice with regards to EPS complexation, and key physicochemical and biological data will be evaluated. - The bioavailability of Fe for phytoplankton growth during sea-ice melt will be investigated through laboratory-based experiments designed to mimic spring conditions. - The distribution of other bioactive trace elements in the Antarctic sea-ice environment will be examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirement. Taken from the 2008-2009 Progress Report: Progress against objectives: In the last twelve months we achieved all the objectives planned for the shore-based sample processing and analysis from the SIPEX voyage (fieldwork September-October 2007). An extensive and unique seasonal and spatial data set was put together including parameters such as ice texture, salinity, temperature, Chlorophyll a, particulate organic carbon (POC), dissolved organic carbon (DOC), macro-nutrients (silicate, phosphate and nitrate), and exoplysaccharides (EPS, using both alcian blue and PSA methods). Dissolved iron (dFe) and total dissolvable iron (TDFe) were analysed by flow injection - chemiluminescence (FIA-CL) analysis in Hobart. Polycarbonate (PC) filters (Nuclepore 0.2 micron pore size) retaining particulate metals were digested in a mixture of strong, ultrapure acids (750 micro litre 12N HCl, 250 micro litre 40% HF, 250 micro litre 14N HNO3) on a hotplate at 125 degrees C for 8 h. The procedure was successfully applied to plankton, estuarine and river sediment reference materials to verify the recovery of the digestion treatment. The concentrations of particulate iron (PFe) were determined by high resolution ICP-MS at the Central Science Laboratory at UTAS. This data has been quality-controlled, analysed, interpreted and published (see below). Due to the fact that logistical support was not possible for 2008/09 (insufficient berths at Casey Station) despite approval of our project, the field component of the project was delayed. Taken from the 2009-2010 Progress Report: Progress against objectives: Monthly Milestones of PhD student Pier van der Merwe: Successful Antarctic research expedition occurred in Oct-Dec 2009 at Casey Station Antarctica with logistical support from AAS project #3026 (flight on FA02 and berths at Casey station as well as field support of personnel). OCT-DEC 2009 - Antarctic time series data collection and processing successful. Data analysis scheduled for Jan - Mar. Write up of last paper(s) scheduled for Mar-June. Final completion of thesis due in August. DEC - Chlorophyll a data analysed JAN - FIA and CLECSV analyses start simultaneously FEB - Finish FIA analyses and attend Ocean science meeting in Portland Oregon. MAR - Finish CLECSV analyses and run POC and PFe digestions and analyses. Scheduled with Thomas Rodemann and Ashley Townsend at the CSL, UTAS. APR - MAY Data analysis and write up of 3rd paper, and possibly 4th based on field work at Casey station Oct-Dec 2009. See the child metadata records for more information about the data.

This work was completed as part of the SIPEX - Sea Ice Physics and Ecosystem eXperiment - voyage. Adapted from the SIPEX website: During SIPEX we investigated the biogeochemistry of iron (Fe), including a comprehensive examination of its distribution, speciation (i.e. the different forms of Fe), cycling and its role in fuelling sea ice-based and pelagic algal communities. A major part of this research concentrated on the influence of organic exopolysaccharides (EPS) on Fe solubility and its bio-availability. The distribution of other bioactive trace elements was also examined as a means of fingerprinting the source(s) of Fe, as well as indicating their biological requirements. ######### Data on the small- to medium scale (0.1-1000 m) spatial and temporal distribution of Fe and EPS in sea ice cores, surface snow, brine and underlying seawater were determined in each sampled medium by the interdisciplinary team working on the SIPEX project (AAS 3026) in the East Antarctic sector in September/October 2007. Data include Chlorophyll a, salinity, temperature, sea-ice thickness, ice texture analysis, macro-nutrients (nitrate, phosphate, silicate), oxygen stable isotopes, POC and DOC, EPS, iron. This work was completed as part of AAS (ASAC) project 3026. See the parent metadata record (ASAC_3026) for more information.