Iron Distribution and Effects on Phytoplankton Growth in the Seasonal Sea Ice Zone

• Other Authors: SEDWICK, PETER (hasPrincipalInvestigator), SEDWICK, PETER (processor), BOWIE, ANDREW ROSS (hasPrincipalInvestigator), BOWIE, ANDREW ROSS (processor), Australian Antarctic Data Centre (publisher)
• Format: Dataset
• Language: unknown
• Published: Australian Antarctic Data Centre
• Subjects: biota; geoscientificInformation; oceans; OCEAN TRACERS; EARTH SCIENCE; OCEAN CHEMISTRY; ORGANIC MATTER; TRACE ELEMENTS; PHYTOPLANKTON; BIOSPHERE; AQUATIC ECOSYSTEMS; PLANKTON; CTD; DIMETHYLSULFIDE; DIMETHYLSULFONIOPROPIONATE; DIMETHYLSULFOXIDE; DISSOLVED IRON; SEA ICE; SHIPS; R/V AA > R/V Aurora Australis; OCEAN > SOUTHERN OCEAN > CLIVAR SR3 transect; GEOGRAPHIC REGION > POLAR; Antarctic; Southern Ocean; Antarc*; aurora australis; Sea ice
• Online Access: https://researchdata.edu.au/iron-distribution-effects-ice-zone/699664; https://doi.org/10.4225/15/55669D573315A; https://data.aad.gov.au/metadata/records/ASAC_1301; http://nla.gov.au/nla.party-617536

Peter Sedwick collected water column samples (6 depths, less than 350m) and measured dissolved iron in these samples, using specialised trace-metal clean techniques, at 9 stations along the SR3 transect between 47 deg S and 66 deg S. These are the first such data for this oceanographic sector during spring. The dissolved iron levels were generally very low (less than 0.2 nM nM) in the upper water column, particularly south of the Subantarctic Front, and surprisingly there was no evidence of significant iron inputs from melting sea ice in our study region. Ongoing work quantified various size fractions of dissolved iron as well as total acid soluble iron. In addition, Jack DiTullio collected water samples for measurements of five biogenic sulfur pools at most shallow water CTD casts. The sulfur pools measured include: dimethylsulfide (DMS), particulate and dissolved dimethylsulfoniopropionate (DMSP) and particulate and dissolved pools of dimethylsulfoxide (DMSO). Taken from the referenced paper: A shipboard-deployable, flow-injection (FI) based instrument for monitoring iron(II) in surface marine waters is described. It incorporates a miniature, low-power photoncounting head for measuring the light emitted from the iron-(II)-catalyzed chemiluminescence (CL) luminol reaction. System control, signal acquisition, and data processing are performed in a graphical programming environment. The limit of detection for iron(II) is in the range 8-12 pmol L-1(based on 3s of the blank), and the precision over the range 8-1000 pmol L-1 varies between 0.9 and 7.6% (n )4). Results from a day-night deployment during a north to-south transect of the Atlantic Ocean and a daytime transect in the Sub-Antarctic Front are presented together with ancillary temperature, salinity, and irradiance data. The generic nature of the components used to assemble the instrument make the technology readily transferable to other laboratories and the modular construction makes it easy to adapt the system for use with other CL chemistries.