Southern Ocean CTD data collected from the CASO cruise of the Aurora Australis, 2007-2008

Taken from the accompanying report:

Oceanographic measurements were collected aboard the Aurora Australis on cruise au0806 (voyage 6 2007/2008, 22nd March 2008 to 17th April 2008). This cruise completed the CASO oceanographic program begun on the CEAMARC cruise (au0803, voyage 3 2007/2008), with a full occupation of the SR3 transect between Antarctica and Tasmania.

CASO program objectives were:

1. to measure changes in water mass properties and inventories throughout the full ocean depth between Australia and Antarctica along 140oE (the CLIVAR/WOCE repeat section SR3), as part of a multi-national International Polar Year program to obtain a circumpolar snapshot of the Southern Ocean in austral summer 2007-8;

2. to estimate the transport of mass, heat and other properties south of Australia, and to compare results to previous occupations of the SR3 line and other sections in the Australian sector;

3. to deploy moorings near the Adelie Depression (142-145oE) as part of a joint Australia-France-Italy program to monitor changes in the properties and flow of Adelie Land Bottom Water;

4. to identify mechanisms responsible for variability in ocean climate south of Australia.

The CASO program (with a full occupation of the SR3 transect) was originally scheduled for a single cruise. The shipping schedule was re-arranged following an unexpected period in drydock, due to a problem with the ship's thrusters, and as a result the CASO program was split over the two cruises. Several of the southern stations occupied on the first cruise au0803 were repeated on the second cruise au0806, to minimise the impact on the data set of the time gap between the cruises.

A total of 131 CTD vertical profile stations were taken on au0803, and 73 CTD station were taken on au0806, most to within 20 metres of the bottom. During the 2 cruises, over 2900 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite and silicate), 18O, CFC's, dissolved inorganic carbon, alkalinity, 14C, dissolved organic carbon, density (i.e. analysis of the effect of water composition on water density), germanium/silica/boron isotopes, trace metals, neodymium, chlorophyll-a, cell counts, pigments, genetic analyses, and other biological parameters, using a 24 bottle rosette sampler. Full depth current profiles were collected by an LADCP attached to the CTD package, while upper water column current profile data were collected by a ship mounted ADCP. Data were also collected by the array of ship's underway sensors.

This report describes the processing/calibration of the CTD data, and details the data quality. An offset correction is derived for the underway sea surface temperature and salinity data, by comparison with near surface CTD data. CTD station positions are shown in Figures 1 and 2, while CTD station information is summarised in Table 1. Mooring and drifter deployments/recoveries are summarised in Table 14. Mooring data from the Adelie Depression deployments are discussed in the mooring data reports Rosenberg (unpublished report, 2009) and Meijers (unpublished report, 2009). Further cruise itinerary/summary details can be found in the voyage leader reports (Australian Antarctic Division unpublished reports: Riddle, V3 2007/08 VL report; Rintoul, V6 2007/08 VL report). Hydrochemistry and CFC cruise reports are in Appendix 1 and Appendix 2.

Details about the data are available in a readme file and a full report in the download file.

Identification info

Alternate title: Southern Ocean CTD data collected from the CASO cruise of the Aurora Australis, 2007-2008

Date (Publication): 2010-06-25

Edition: 1

Citation identifier

Dataset DOI

Title: Information and documentation - Digital object identifier system

Date (Publication): 2012-04-23

Citation identifier: ISO 26324:2012

Citation identifier: doi:10.4225/15/58ad18180df56

Originator

Rosenberg, M. and Rintoul, S.

Publisher

Australian Antarctic Data Centre

Principal investigator

ROSENBERG, MARK

ACE CRC, c/- University of Tasmania

Private Bag 80

Hobart

Tasmania

7001

Australia

+61 3 6226 7651

+61 3 6226 2973 (facsimile)

Collaborator

RINTOUL, STEVE

CSIRO Marine and Atmospheric Research

GPO BOX 1538

Hobart

Tasmania

7001

Australia

+61 3 6232 5393

+61 3 6232 5123 (facsimile)

Name: CAASM Metadata

Website: https://data.aad.gov.au/metadata/records/au0806_CASO_CTD

Status: Completed

Custodian

AU/AADC > Australian Antarctic Data Centre, Australia - AADC, DATA OFFICER (DATA CENTER CONTACT)

Australian Antarctic Division

203 Channel Highway

Kingston

Tasmania

7050

Australia

+61 3 6232 3244

+61 3 6232 3351 (facsimile)

Topic category

Oceans

Extent

Description: Temporal Coverage

Temporal extent

TimePeriod: 2008-03-22 2008-04-17

Extent

Description: Vertical Extent - Depth

Vertical element

Minimum value: 0

Maximum value: 4892

Identifier: urn:x-ogc:def:cs:EPSG:6498

Name: Vertical CS. Axis: depth (D). Orientation: down. UoM: m.

Identifier: urn:x-ogc:def:axis:EPSG:113

Name: depth