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EARTH SCIENCE > OCEANS > SALINITY/DENSITY > CONDUCTIVITY

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  • This indicator is no longer maintained, and is considered OBSOLETE. INDICATOR DEFINITION Measurements of sea surface salinity in the Southern Ocean. Measurements are averaged over latitude bands: 40-50 deg S, 50-60 deg S, 60 deg S-continent. TYPE OF INDICATOR There are three types of indicators used in this report: 1.Describes the CONDITION of important elements of a system; 2.Show the extent of the major PRESSURES exerted on a system; 3.Determine RESPONSES to either condition or changes in the condition of a system. This indicator is one of: CONDITION RATIONALE FOR INDICATOR SELECTION Australian and Antarctic climate and marine living resources are sensitive to the distribution of ocean salinity. Sea surface values are relatively easy to monitor, and therefore can be used as a relevant indicator of the state of the ocean environment. The information provided by long records of sea surface salinity is needed to detect changes in the Southern Ocean resulting from climate change; to test climate model predictions; to develop an understanding of links between the Ocean and climate variability in Australia; and for sustainable development of marine resources. DESIGN AND STRATEGY FOR INDICATOR MONITORING PROGRAM Spatial scale: Southern Ocean: 40 deg S to the Antarctic continent Frequency: Monthly averages over summer Measurement technique: Measurements of sea surface salinity from Antarctic supply ships. RESEARCH ISSUES Sea surface salinity has not been previously used as a spatially averaged environmental indicator. Some experimentation with past data are required to define the most appropriate averaging strategy. New technologies like profiling Argo floats need to be exploited to provide better spatial and temporal coverage of salinity in the Southern Ocean. LINKS TO OTHER INDICATORS Sea surface temperature Sea ice extent and concentration Chlorophyll concentrations concentrations

  • Australian fishing vessels involved in exploratory fishing for Antarctic toothfish in East Antarctica under the auspices of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) collected data required under their exploratory fishing permit. Conductivity, temperature and depth (CTD) loggers were attached to bottom longlines sets to collect data while fishing for Antarctic toothfish in Antarctic waters. The data relates to Objective 2 of the research work required: Collect and utilise environmental data to inform spatial management approaches for the conservation of toothfish, bycatch species and representative areas of benthic biodiversity (CCAMLR 2016). Data were collected on two fishing vessels during the austral summers (December to February) of 2015/16, 2016/17 and 2017/18 in CCAMLR Divisions 58.4.1 and 58.4.2. The data were collected with DST CTD (Conductivity, Temperature and Depth Recorder) from Star-Oddi (Conductivity: 13-50 mS/cm, maximum depth: 2400 m). Files were then downloaded with SeaStar and are available in the original data format. Recordings were made at 5 or 10 second intervals for the duration of up to around 24h, recording data throughout the water column while setting the longline and then while stationary on the sea floor. Each deployment has data on time, temperature (degrees C), salinity (psu), conductivity (mS/cm) and depth (m), and is linked to geographical coordinates. Number of deployments: 2015/16: 34 2016/17: 31 2017/18: 75 CCAMLR (2016) Joint research proposal for the Dissostichus spp. exploratory fishery in East Antarctica (Divisions 58.4.1 and 58.4.2) by Australia, France, Japan, Republic of Korea and Spain. Delegations of Australia, France, Japan, Republic of Korea and Spain. Report to Fish Stock Assessment Working Group, WG-FSA-16/29, CCAMLR, Hobart, Australia. Dates and times in the data files are recorded in UTC. Further information is provided in a pdf document in the download file.

  • 3 CTD casts were conducted during a limited marine science voyage by the Nella Dan to Prydz Bay during the 1985-1986 summer Antarctic season. The voyage leaser was Tom Maggs, and the deputy leader was Peter Heyward. The ship followed the schedule listed out below: Hobart 29-Dec-1985 04-Jan-1986 Edgeworth David 13-Jan-1986 17-Jan-1986 Shackleton Ice Shelf Davis 21-Jan-1986 21-Jan-1986 Marine Science 22-Jan-1986 23-Jan-1986 Marine Science Prydz Bay Davis 24-Jan-1986 26-Jan-1986 Marine Science 27-Jan-1986 27-Jan-1986 Marine Science Prydz Bay Mawson 29-Jan-1986 01-Feb-1986 Davis 03-Feb-1986 04-Feb-1986 Mawson 06-Feb-1986 06-Feb-1986 Davis 09-Feb-1986 09-Feb-1986 Edgeworth David 13-Feb-1986 13-Feb-1986 Shackleton Ice Shelf Casey 14-Feb-1986 14-Feb-1986 Hobart 22-Feb-1986 24-Feb-1986

  • CTD casts were taken through holes in the ice floe at various locations during ice stations 3, 4, 6 and 7. Two Seabird 37M microcats were used. One microcat did not log time, whereas the other did. An Idronaut Ocean Seven 304 CTD (manufactured in Italy) was used during ice stations 7 and 8. CSV files are provided. A single file represents a set of casts at a single location. The files are organised in columns as: Column 1: Temperature (C) Column 2: Conductivity Column 3: Pressure Column 4: Salinity (ppt) Column 5: Date (DD MMM YYYY), UTC Column 6: Time (HH:MM:SS), UTC For the Seabird 37M (2006 model) belonging to Dr Hutchings, time on the microcat is set to UTC, to the second. For the AWI Seabird 37M (1999 model), time is not output. This microcat dribbled data to a laptop at 1Hz. Ice Station 3: A microcat was placed at about 7m below the surface (5m below the ice) at Ridge site 1. Salinity sensor was iced up on this cast Ice Station 4: Cast 1: 100m cast through the ROV hole on Oct 6th 10:30 UTC. Cast 2: 10m cast at the trace gas site, on Oct 8th 06 UTC. Cast 3: 100m cast at the trace gas site, on Oct 8th 09:30 UTC. Ice Station 6: Cast 1: 100m at ridge site 1 , on Oct 13th 03 UTC. Cast 2: 10m casts at Trace Gas site, on Oct 13th 04:30 UTC. F Note that salinity sensor was iced on 10m cast at trace gas site. Cast 3: Deployment at 7m depth at ridge site 1, on Oct 13th 06UTC. Cast 4: 100m cast at ridge site 1, on Oct 14th 23 UTC. Note that microcat stopped recording at about 65m in downcast. Ice Station 7: - CTD casts with Seabird 37M microcat: Cast 1: 100m cast, Transducer Hole A, at active ridge. 20th Oct 03:00Z. Power failed 60m into downcast. Cast 2: 30m cast, Y-axis 50m core hole. 20th Oct 05:15Z Cast 3: 40m cast followed by 100m cast. Y-axis 100m ADCP hole. 21st Oct 00:00Z. Power failed at 60m. Cast 4: 15m casts. Y-axis 50m core hole. 21st Oct 05:15Z Cast 5: ROV Hole. With Polly's pinger. 21 Oct 09:30Z. Power failure at 86m. - CTD casts with Gerhard Dieckman's Seabird microcat. Note this microcat does not output time, but dribbles 1Hz data. Cast 6: Transponder Hole near new ridge. 23rd Oct 06:30Z. Cast 7: Trace Metal / Bio site. 23rd Oct 07:30Z. Cast 8: At ROV Hole Ice Station 8: Synoptic (3 hourly) CTD casts Roster of CTD casts is contained in file 'CTD_time.xls'. This table is pasted below. Please note that the names of excel files containing the raw data are presented in this table. Filenames: Ice Station 3: Filename: 20121004/20121004_IceStation3_microcat_all.dat. Ice Station 4: Cast 1: Filename: 20121006_IceStation4_microcat_cast1.dat Cast 2: Filename: 20121008_IceStation4_microcat_cast2_gerhard.dat Cast 3: Filename: 20121008_IceStation4_microcat_cast3_gerhard.dat Ice Station 6: Cast 1: Filename: 20121013_IceStation6_microcat_cast1_ridge.dat Cast 2: Filename: 20121013_IceStation6_microcat_cast2_gerhard.dat Cast 3: Filename: 20121013_IceStation6_gerhardCat_ridge_052700.dat Cast 4: Filename: 20121014_IceStation6_microcat_ridge.dat Ice Station 7: CTD casts with Seabird 37M microcat: Cast 1: Filename: 20121020_IceStation7_microcat_transponder_newRidge.dat Cast 2: Filename: 20121020_IceStation7_microcat_50m.dat Cast 3: Filename: 20121021_Station7_100m.dat Cast 4: Filename: 20121021_Station7_50m.dat Cast 5: Filename: 20121021_Station7_ROVhole_plusPolly2_tryagain.dat CTD casts with the AWI Seabird microcat: Cast 6: Filename: 20121023_gerhardCat.dat Cast 7: Filename: 20121023_gerhardCat_hole2.dat Cast 8: Filename: CTD_jenny_20121023.xls Ice Station 8: Synoptic (3 hourly) CTD casts: The data files are: CTD_jenny_20121023.xls CTD_jenny_20121028.xls CTD_jenny_20121030.xls CTD_jenny_20121031.xls CTD_jenny_20121101(1).xls CTD_jenny_20121101(2).xls CTD_jenny_20121102.xls CTD_jenny_20121103.xls CTD_jenny_20121104.xls

  • Multiple CTD (conductivity, temperature, depth) casts were deployed during the SIPEX II AAD Marine Science voyage in September-November 2012. The system uses a descending rosette capable of holding up to 24 CTD bottles. During this voyage the CTD rosette also housed two krill traps (using controllable lights) and two GoPro cameras contained in pressurised, waterproof containers that were used to monitor the krill traps and view objects both on the sea bed and in the water column. Some functions of the GoPro cameras could be controlled from within the ship using the same transmission cable used by the CTD system. These functions included being able to change the focus setting of the cameras or start/stop recording. More information about the krill traps and cameras is contained in the SIPEX II Bottom Krill dataset. When a bottle is 'fired' from the ship it briefly opens, draws in water samples and closes again. It is not reopened until it is brought on board the ship. Bottles are opened at different depths to obtain samples from these depths. The depths vary from cast to cast and so are recorded in the CTD Log sheets (contained in this dataset as PDF files). Only raw data is contained in this dataset. The raw data was used by a variety of experiments during the SIPEX II voyage to produce results applicable to each experiment. Thanks go to the P and O crew of the RV Aurora Australis for their assistance during CTD operations.

  • We deployed CTD sensors on five of the SIPEX 2 ice stations for collecting temperature and salinity of the water column under the sea ice. This dataset contains the raw data as outputted from the CTD in Excel format, in English. The dates that the CTD were deployed are in the file names (i.e. 20121023 is October 23, 2012).

  • Data were collected during the 1997-1998 austral summer on voyages by the Aurora Australis and Southern Surveyor. Taken from the abstract of the referenced paper: Oceanographic processes in the subantarctic region contribute crucially to the physical and biogeochemical aspects of the global climate system. To explore and quantify these contributions, the Antarctic Cooperative Research Centre (CRC) organised the SAZ Project, a multidisciplinary, multiship investigation carried out south of Australia in the austral summer of 1997-1998. Here we present a brief overview of the SAZ Project and some of its major results, as detailed in the 16 papers that follow in this special section. The Southern Ocean plays an important role in the global oceanic overturning circulation and its influence on the carbon dioxide contents of the atmosphere. Deep waters upwelled to the surface are rich in nutrients and carbon dioxide. Air-sea interaction modifies the upwelled deep waters to form bottom, intermediate, and mode waters, which transport freshwater, oxygen, and carbon dioxide into the ocean interior. The overall effect on atmospheric carbon dioxide is a balance between outgassing from upwelled deep waters and uptake via both dissolution in newly formed waters (sometimes referred to as the solubility pump) and the transport of photosynthetically formed organic carbon to depth in settling particles (referred to as the biological pump). Determining the variations in the overturning circulation and the associated carbon fluxes in the past and their response to increased anthropogenic emissions of carbon dioxide in the future is essential to a full understanding of the controls on global climate. At present the upwelled nutrients are incompletely used. Low light in deep wind-mixed surface layers, lack of the micronutrient iron, and other factors restrict phtyoplankton production so that Southern Ocean surface waters represent the largest high-nutrient, low chlorophyll (HNLC) region in the world.

  • Metadata record for data from ASAC Project 1101 See the link below for public details on this project. ---- Public Summary from Project ---- Most of our knowledge of the Antarctic marine ecosystems comes from summer surveys. There are very few observations of this ecosystem in winter and there is a fundamental lack of knowledge of understanding of even basic questions such as 'what is there?' and 'what's it doing?'. The proposed visit to the sea ice zone in winter is a rare opportunity to conduct observations on phytoplankton, krill, birds, seals and whales, so that we can begin to understand the biological processes that go on in winter. Data for this project were intended to be collected on a 1998 winter voyage of the Aurora Australis, but a fire on board meant that the voyage had to return to port before work could be carried out. Data were then collected the following year during a 1999 winter voyage of the Aurora Australis (IDIOTS), which ran from July to September. Data attached to this metadata record, include zooplankton and CTD data collected from the Mertz Glacier region. The data have been compiled by Angela McGaffin, and can be found in the "processed" folder of the download file. Original datasets are also available in the "Original Datasets" folder.

  • Oceanographic measurements conducted on voyage 1 of the Aurora Australis of the 1999-2000 season. These data comprise CTD (Conductivity, Temperature and Depth) and ADCP (Acoustic Doppler Current Profiler) data. These data were collected by Mark Rosenberg. This metadata record was completed by AADC staff when the data were discovered bundled with acoustics data during a data cleaning exercise. Basic information about voyage 1: Polynya study off Mertz Glacier at about 145 deg E. The vessel departed from Port Arthur for the polynya study site without returning to Hobart. The voyage also deployed moorings and delivered biologists (for seal and penguin programs) and a small quantity of essential supplies and mail to Macquarie Island. Leader: Dr Ian Allison Deputy Leader: Dr Tony Worby Cargo Supervisor: Dr Vicky Lytle See the readme files in the downloads for more information.

  • Oceanographic measurements conducted on voyage 6 of the Aurora Australis of the 2000-2001 season. These data comprise CTD (Conductivity, Temperature and Depth) and ADCP (Acoustic Doppler Current Profiler) data. These data were collected by Mark Rosenberg. This metadata record was completed by AADC staff when the data were discovered bundled with acoustics data during a data cleaning exercise. Basic information about voyage 6: The voyage will complete a range of Marine Science activities off the Mawson Coast, and off the Amery Ice Shelf before calling at Davis to retrieve summer personnel and helicopters prior to returning to Hobart. Science equipment calibration will be undertaken at Mawson. (Marine Science activities were interrupted when the Aurora Australis was required to provide assistance in the Polar Bird's attempt to reach Casey, complete the station resupply and return to open water.) Leader: Dr Graham Hosie Deputy Leader: Mr Andrew McEldowney See the readme files in the downloads for more information.