This dataset contains vertical profiles of particles in the upper water column (60 m depth) at six sites. A laser optical plankton counter (LOPC) was deployed through a hole in the sea ice, or from the stern of the Aurora Australis, and lowered to 60 m, logging as it was lowered. The LOPC records particles in the size range 100 um to 20 mm, though the small aperture (7 cm x 7 cm) means that the largest particles are probably only sampled rarely. For each site, the data are presented as normalised biomass for a series of equivalent spherical diameters (ESD). ESD is based on measurements of length and width of animals likely to be sampled via the LOPC (i.e. animals that are sampled at the same time with a traditional plankton net). The data were collected on the SIPEX II voyage of the Aurora Australis, from 14/9/2012 to 16/11/2012. Sites were all located in first year pack ice; the ship would nudge up to a floe and then samples of ice, zooplankton, etc. were collected directly by working on the floe. The LOPC was either deployed through a large hole in the pack ice, or it was deployed off the stern of the AA. Method of deployment did not really have an impact on the data collected, it was more a logistical decision based on conditions.

This dataset will be comprised of measurements taken from trace metal water column samples collected during the SIPEX II Antarctic marine science voyage in 2012. In its current form no sample analysis has been performed. The dataset simply contains the log sheets for the Trace Metals Rosette (TMR) deployments as well as the output files from the TMR software (General Oceanics). Water samples for dissolved trace metal measurements were collected from the surface (15m) down to the 1000m using an autonomous intelligent rosette system (General Oceanics, USA) specially adapted for trace metal work and deployed on a Dyneema rope. The rosette was equipped with 12x10-L Niskin-1010X bottles specially modified for trace metal water sampling. This system has been successfully deployed on the RSV Aurora Australis during voyages au0703 and au0806. Care was taken to avoid any contamination from the ship and the operating personnel. Water samplers were processed aboard under an ISO class 5 trace-metal-clean laminar flow bench in to a trace-metal-clean laboratory container on the ship's trawl deck. All transfer tubes, filtering devices and sample containers were rinsed liberally with sample before final collection. Samples were then drawn through C-Flex tubing (Cole Parmer) and filtered in-line through 0.2 micron pore-size acid-washed capsules (Pall Supor membrane, Acropak 200). Filtered and unfiltered samples were collected in acid-cleaned 125ml Nalgene LDPE bottles for analysis of dissolved trace metals. Samples were also collected for the determination of stable isotopes of nitrogen and carbon. As well, filtered samples were taken for macro-nutrient analysis in the lab (2 small vials per Niskin, frozen). Regular sampling depths were as follows: 1000m, 750m, 500m, 300m, 200m, 150m, 125m, 100m, 75m, 50m, 30m, 15m. At a subset of the SIPEX II ice stations, filtered samples were also collected for Iron(II) analysis aboard the ship by Christina Schallenberg (in the trace-metal-clean laboratory container), and unfiltered samples were collected for analysis of mercury and methyl-mercury by Caitlin Gionfriddo (caitlingio@gmail.com).

During the ice stations, measurements of the air CO2, concentration for CO2 flux between sea ice and atmosphere were made with the chamber technique. Air-sea ice CO2 fluxes were measured over the sea ice with semi-automated chambers. Sample air from the chamber is passed through Teflon tubes connected to non-dispersive infrared (NDIR) analyzer (Model 800, LICOR Inc., USA) that was connected to a system controller and data logger (Model 10x, Campbell Scientific Inc., USA), that controls the opening/closing of the chambers as well. During the observation period, the CO2 flux was measured under three different conditions or surface types: (1) a chamber was installed above snow; (2) over the bare ice after removing the snow; (3) slush layer after removing the snow and slush crystals. The CO2 concentration in the chamber was measured every 5 s during experiments lasting 20 minutes for each chamber. A one hour cycle of measurements therefore consist of three 20 minute periods from each chamber (i.e. surface type). Data available: excel files containing sampling station name for each spreadsheet, dates, sampling time and air CO2 concentration as output voltage from NDIR (to indicated as ppm we need to calculate, but, not yet done this process) in the air and chamber for CO2 flux measurement. Also see the record - SIPEX_II_Gas_Flux

During the ice stations, sea ice, brine/slush, snow and under-ice water sampling were collected for oxygen isotopic ratio. Ice cores were collected using a Kovacs 9 cm diameter ice corer. The ice core for oxygen isotopic ratio was cut directly after retrieval with a stainless steel folded saw. The core was cut generally into 10 cm sections (20 cm when ice cores were higher than 200 cm) and put into zip-lock polyethylene bags. Care was taken to use laboratory gloves when collecting the cores. For brine sampling, partial core holes were drilled into the ice (so called sackholes), usually to a depth of 25 cm and 50 cm. At site with flooding, brine collection was not possible, and samples of the surface slush were collected instead. Slush was collected by plastic shovel. Snow samples were also collected. Under-ice water was collected with a Teflon water sampler (GL Science Inc., Japan) 1, 3, 5 m below the bottom of the sea ice. In addition, CTD water sampling was examined at each station. The cores were taken back to the ship, and transferred to the gas tight bag (GL Science Inc., Japan), and then ice was melted at about +4 degrees C in a refrigerator. Melted samples were sub-sampled for each component. The snow samples were treated in the same manner as the sea ice samples for further analysis. Oxygen isotopic ratio was determined with a mass spectrometer (DELTA plus; Finnigan MAT, USA) in Hokkaido University. Oxygen isotopic ratio in per mil (parts per thousand) was defined as the deviation of H2 18O/H2 16O ratio of the measured sample to that of the standard mean ocean water (SMOW). The precision of oxygen isotopic ratio analysis from duplicate determinations is plus or minus 0.02 parts per thousand (Toyota et al., 2007). Data available: excel files containing sampling station name, dates, and oxygen isotopic ratio.

Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. To determine size and biomass, key species were measured. Measurements of Prosome, Urosome and Total length are provided. The zooplankton were taken from samples collected with umbrella nets, RMT1 net and sea ice cores. They were measured under a Leica M165C steromicroscope using an ocular micrometer. The ocular micrometer was calibrated against a stage micrometer (+/- 0.01 um).

Note - these data are an inadvertent copy of another metadata record - but because they have a dataset DOI they cannot be deleted. For the "master" copy of the dataset, see the metadata record at: https://data.aad.gov.au/metadata/records/SIPEX_II_Underway_Snowfall Matlab file containing raw data snowfall data collected aboard the RV Aurora Australis using Campbell Scientific dataloggers. Two Wenglor brand YHO3NCT8 photoelectric sensors were mounted on the forward railing of the ship's "monkey deck". The beam heights of the sensors were 18cm above the upper railing, oriented parallel to the railing (perpendicular to the long-axis of the ship), approximately 6m apart. The port sensor was purchased in 2012, from a batch of these sensors manufactured in a new Eastern European factory while the starboard sensor came from a lot purchased in 2007, manufactured in Wenglor's German factory and extensively tested for use in snow. Pulse counts measured by the port sensor were consistently lower in magnitude than those recorded during the same interval by the starboard sensor. It is not currently clear whether this was due to the ship's tendency to be oriented with the wind to starboard, or whether this is due to differences in instrument characteristics. Data recorded between 17/9/2012 and 26/10/2012 was logged by a CR10x datalogger. Data recorded after 26/10/2012 was logged by a CR1000 datalogger. Information on converting the pulse-count data into a mass flux of snow is contained in Leonard, K.C. and R.I. Cullather (2008) Snowfall measurements in the Amundsen and Bellingshausen Seas, Antarctica. Proceedings of the Eastern Snow Conference, 65, 87- 98. These two datasets are identical, but have been separated into two matlab structures contained in the same "shipsnow.mat" file: "snow" and "snow2". Data contained in these structures includes the following variables, with units: Datenm: matlab 'datenumber'. Change to conventional format using the "datevec()" command Port: beam interruptions per 10s interval, port-side sensor Stbd: beam interruptions per 10s interval, starboard-side sensor Ptemp: temperature of a thermistor mounted beneath the datalogger's wiring panel. The datalogger was contained in a fiberglass box, strapped into the starboard side observation shelter on the monkey deck. Volt: voltage received and transmitted by the datalogger. Power came from a 12v 1Ah converter plugged into the ship's power supply.

Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. The umbrella net was 2 metres long, 28 cm2 mouth area and mesh size of 100 um. The net was lowered through holes drilled through the pack ice and lowered to 100 m. It was pulled slowly by hand to the surface, closed and brought back through the ice hole. The contents were preserved in 5% buffered formaldehyde and examined under a Leica M12 in the laboratory. Species were identified to the lowest taxon possible.

During the ice stations, sea ice, brine/slush, snow and under-ice water sampling were collected for CO2 concentration measurement as dissolved inorganic carbon (DIC). Ice cores were collected using a Kovacs 9 cm diameter ice corer. The ice core for DIC was cut directly after retrieval with a stainless steel folded saw. The core was cut generally into 10 cm sections (20 cm when ice cores were higher than 200 cm) and put into zip-lock polyethylene bags. Care was taken to use laboratory gloves when collecting the cores. For brine sampling, partial core holes were drilled into the ice (so called sackholes), usually to a depth of 25 cm and 50 cm. At site with flooding, brine collection was not possible, and samples of the surface slush were collected instead. Slush was collected by plastic shovel. Snow samples were also collected. Under-ice water was collected with a Teflon water sampler (GL Science Inc., Japan) 1, 3, 5 m below the bottom of the sea ice. In addition, CTD water sampling was examined at each station. The cores were taken back to the ship, and transferred to the gas tight bag (GL Science Inc., Japan), and then ice was melted at about +4 degrees C in a refrigerator. Melted samples were sub-sampled for each component. The snow samples were treated in the same manner as the sea ice samples for further analysis. The dissolved inorganic carbon (DIC) of seawater was determined by coulometry [Johnson et al. 1985] using a coulometer (CM5012, UIC Inc., Binghamton, NY, USA). DIC measurement was calibrated with reference seawater materials (Batch AG; KANSO Technos Co., Ltd., Osaka, Japan) traceable to the Certified Reference Material distributed by Prof. A. G. Dickson (Scripps Institution of Oceanography, La Jolla, CA, USA). The standard deviation for DIC calculated from 20 subsamples taken from a reference seawater material (DIC = 2084.5 micro mol L-1) was 1.4 micro mol L-1. Data available: excel files containing sampling station name, dates, and DIC concentration.

Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. As part of the collections sea ice cores were collected to describe the ice habitat during the period of zooplankton collections. Ice cores were taken with a 20 cm diameter SIPRE corer and sectioned in the field with an ice core. Temperature was measured in the section using a spike thermometer and slivers of each section were melted without filtered water to record salinity. The remainders of each section were melted at 4oC in filtered seawater and the melted water was used to measure chlorophyll a concentration, and meiofauna species and abundance. Meiofauna were counted and identified using a Leica M12 microscope: to species in most cases and down to stage during 2012.

Zooplankton were collected during the winter-spring transition during two cruises of the Aurora Australis: SIPEX in 2007 and SIPEX II in 2012. As part of the collections sea ice cores were collected to describe the ice habitat during the period of zooplankton collections. Ice cores were taken with a 20 cm diameter SIPRE corer and sectioned in the field with an ice core. Temperature was measured in the section using a spike thermometer and slivers of each section were melted without filtered water to record salinity. The remainders of each section were melted at 4oC in filtered seawater and the melted water was used to measure chlorophyll a concentration, and meiofauna species and abundance.