Physical and biogeochemical properties of rotten East Antarctic summer sea ice

Brief description

This dataset includes the following parameters collected from sea-ice cores during RSV Aurora Australis' Voyage 2 2016-17 around Wilkes Land and George V Land, East Antarctica: temperature, salinity and stable oxygen isotopes; macro-nutrients, chlorophyll a and phaeopigments; and ice textures.

The dataset is an Excel workbook with the following worksheets:
1. readme - some general information as well as abbreviations and units.
2. stations - time and location of sea-ice stations and some associated ship underway data.
3. sea_ice - parameters listed above as well as brine salinity and porosity calculated following the methods described in the linked manuscript.
4. cores - information on cores collected.
5. brines - data from sea-ice brine collected in core holes.
6. sw0m - data from surface seawater.

Sea ice was sampled around Wilkes Land and George V Land, East Antarctica, during RSV Aurora Australis’ Voyage 2 2016-17 (AAV2 2016-17, 65°-67° S, 109°-148° E) in austral summer (18th Dec 2016 – 13th Jan 2017). A 0.14 m internal diameter trace-metal clean electropolished stainless steel corer (Lichtert Industries, Belgium) was used to extract ice cores. To minimise brine loss, cores were immediately cut into 0.1 m sections using a clean stainless steel saw and stored in sealed acid-cleaned plastic buckets. These were transferred to the ship where the ice was melted at room temperature in the dark before analyses. Additional complete cores were extracted (stored horizontally at -20 °C) for later ice texture analysis. Brine samples were collected from sack holes ~1 m deep, and surface-seawater samples were collected either in full-ice-depth bore holes or beside floes.

Samples were collected from two fast ice (Casey1 and Casey2, ~90 m apart in O’Brien Bay) and seven pack ice stations during AAV2 2016-17. Stations near the Moscow University Ice Shelf and the Mertz Glacier Tongue, Totten1 and Mertz1, respectively, were identified as broken out fast ice and classified as pack ice. The Dalton and Mertz polynyas where these floes were located are areas of open water that occur north of the Moscow University Ice Shelf and Mertz Glacier Tongue, respectively. Most of the stations appeared to be first-year sea ice as they were relatively thin and undeformed. Casey3 was a thick, heavily rafted floe suspected to be multiyear ice. Cores were obtained for measurements of temperature, salinity and stable oxygen isotopes (physico-chemical); macro-nutrients, chlorophyll a and phaeopigments; and ice textures. Six to seven ~0.1 m sections were analysed for each macro-nutrient, chlorophyll a and phaeopigment core. Ice texture cores were only collected from stations Casey1, Totten1, Totten2, SR3-5 (named for its proximity to a nearby long-term hydrography transect station), Mertz1 and Mertz2.

This dataset complements “Duprat, L. (2020) Sea-ice biogeochemistry data collected during voyage 2 of the Aurora Australis in 2016-2017, Ver. 2, Australian Antarctic Data Centre - doi:10.26179/5e21025710cbc”.

Lineage

Progress Code: completed

Statement: Sea-ice cores that were not full-ice-depth:
1. All Casey3.
2. All Totten2.
3. Macro-nutrients, chlorophyll a and phaeopigments from Totten1.

Notes

Purpose
This dataset supports the manuscript titled "Physical and biogeochemical properties of rotten East Antarctic summer sea ice" by Corkill et al. submitted to the Journal of Geophysical Research: Oceans in May 2022.