686 record(s)
Type of resources
Contact for the resource
Provided by
From 1 - 10 / 686
  • Scanned copy of an acoustics log from Casey Station. Data were collected during 1997. There is no accompanying information to go with the log.

  • CAWCR Hindcast* and ECMWF ERA-5** model predictions of wave spectral properties (wave height and period) and corresponding observed data from ACE. Observations are mapped to model grids. Quality control is applied, i.e. cells with a number of points less than 5 and/or with high data variation (Standard Deviation/Mean greater than 0.2) are eliminated. Files are named as follows: WaMoS_vs_CAWCR_Hs.mat WaMoS_vs_CAWCR_Tm.mat WaMoS_vs_ERA5_Hs.mat WaMoS_vs_ERA5_Tp.mat In each file, columns show Latitude (deg.), Longitude (deg.), Time (number of days from January 0, 0000), Model Parameters (Hs, Tp or Tm) and Observed Parameters (Hs, Tp or Tm), respectively. Hs denotes significant wave height in meters, Tp is peak wave period in seconds and Tm is mean wave period based on the first moment of wave spectrum in seconds. The MATLAB file, WaMoSvsModel_FigurePlot.m, can be used to visualise the results. The files dscatter.m and polyfix.m are functions used in the MATLAB script. A sample figure (SampleFigure.png) is also included for users’ reference. * Durrant, T., Greenslade, D., Hemer, M. and Trenham, C., 2014. A global wave hindcast focussed on the Central and South Pacific (Vol. 40, No. 9, pp. 1917-1941). ** Copernicus Climate Change Service (C3S) (2017): ERA5: Fifth generation of ECMWF atmospheric reanalyses of the global climate . Copernicus Climate Change Service Climate Data Store (CDS), Dec. 12, 2018.

  • Metadata record for data from ASAC Project 2315 See the link below for public details on this project. ---- Public Summary from Project ---- Project title: EFFECTS OF THE MODULATION OF THE SURFACE SHEAR STRESS BY THE WAVE FIELD IN A MODEL OF THE SOUTHERN OCEAN This project will investigate the sensitivity of currents and tracer properties in a non-eddy-resolving ocean general circulation model to a formulation of the surface shear stress which takes account of surface air and water velocities induced by the ocean wave field. These velocities will be computed accurately from archived model wave fields and also parameterised from wind and current velocities. From the abstract of the reference paper: We present a basic analysis of the propagation of deep-water waves on curved trajectories. The key feature is that the amplitude of the wave varies transversely, and may in the generation of a short-crested of high amplitude. The properties of there waves are explored, and it is suggested that they are a model for extreme waves, which may violate the conditions under which the classical distribution of wave heights has been derived. In their full development, they are manifested a generic rouge waves. From the 2002/2003 season: The aim of this project was to investigate mode water formation south of Australia in an ocean general circulation model (OGCM). The grant monies were used to employ a numerical modeller (Dr Harun Rashid) who became familiar with the curvilinear grid version of the modular ocean model No. 1 (MOM1) model developed by Ross Murray, and then applied the model with high resolution (0.6 x 0.4 degree) in the region south-west of Tasmania, where recent observations obtained on Franklin cruise (Fr9801) to the west of the SR3 section, indicated that mode water was being formed. The model was found to be inadequate to the task of simulating the formation region, as also were the OCCAM simulations, which have been downloaded and compared with the MOM1 simulations. The reason for this negative conclusion was sought during the course of the project, and it was determined that in the OGCMs: (a) the westward advection south of Tasmania was too strong, and (b) the coefficients of lateral diffusion at deeper levels in the water column were too large. The cruise data, which were investigated by Paul Barker as part of his Ph.D. thesis, indicated that the region of water mass formation south-west of Tasmania, occurs over the depth range of the mode water and the intermediate water and through to the upper circumpolar deep water (300 - 1500 m). It was deduced that the formation mechanism involves the mixing of two source waters, one from the Tasman Sea, the other from the Southern Ocean, which combine to form Tasmanian Subantarctic Mode Water (TSAMW), Tasmanian Intermediate Water (TIW), and probably Tasmanian Upper Circumpolar Deep Water (TUCDW). The dynamical reason for the location of the water mass formation appears to be the existence of a saddlepoint in the streamflow (at which the mean horizontal velocity is zero) over the depth range (300 - 1500m), due to the gyral circulation of the South Australian Basin to the west and the retroflection of the Tasman Outflow to the east. In order to represent this physics, it is very important to simulate correctly the advection at each level in the water column This is not done by the OGCMs, but in the course of the project, the importance of advection on the position of the saddlepoint was demonstrated in a series of simulations using the transports obtained from a simple Sverdrup transport model. The modelled fields were then used to advect temperature and salinity at each level with lateral diffusion coefficients adjusted for the best match with the observed property fields. These 'best fit' lateral diffusion coefficients in the deeper levels were found to be much smaller than those used in the OGCMs. The mechanism outlined above is distinct from that in earlier work in which mode water formation was interpreted using Ekman rather then gyral dynamics, without attention being given to the deeper levels. A simple balance shows that the gyral current is of similar magnitude to the Ekman current in the surface layer, and below the surface layer the Ekman current is absent. Recently (December 2003) Ross Murray has indicated that the problem addressed in this 2002-2003 grant can be revisited, using a 20 year simulation he is obtaining with TPAC NCEP II forcing on a resolution of 1/8 degree. It is our intention to work with Ross in February 2004 to see if the problems detailed above can be overcome, so that the ocean physics in this important water mass formation region can be simulated.

  • A collation of known shipwrecks and vessels lost at sea from the year 1578 until 2013 containing information on year, vessel name, country, last known location, and purpose for the journey. And a collation of recent shipping incidents from 1991 until 2016 containing information on the year of the incident, vessel name, country where known, purpose of the journey and the cause of the incident. Location - listed as nearest land mass used where known. Country - Argentina = AR; Australia = AU; Bahamas = BS; Barbados = BB; Brazil = BR; China = CN; Falkland Islands = FK; France = FR; Germany = DE; Japan = JP; Korea = KR; Liberia = LR; Malta = MT; New Zealand = NZ; Norway = NO; Panama = PA; Peru = PE; Poland = PL; Russia = RU; Spain = ES; South Africa = ZA; Sweden = SE; UK = United Kingdom; US = United States of America Nationality of tourist companies are not all included as the company (principal and sub-chartered), and the ships used, are registered across different countries, some even changing within any given year. Flag state for that year is included where known. NB: vessels ran aground mainly due to severe weather conditions or inadequate hydrographic information Information was compiled for numerous references (Argentina and Chile, 2016; ASOC, 2012; Belgium, 2009; Brazil, 2012a; Brazil, 2012b; Headland, 2009; IAATO, 2000; IAATO, 2002; IAATO, 2003; IAATO, 2011a; IAATO, 2011b; Jones, 1973; Korea, 2011; New Zealand, 2007; New Zealand, 2012a; New Zealand, 2012b; New Zealand, 2015; New Zealand et al., 2011; Norway, 2007; Norway, 2008; People's Republic of China, 2013; Poland, 2016; Reich, 1980; Sweet et al., 2015; United Kingdom, 2008; United Kingdom, 2009).

  • This dataset contains bathymetry (water depth), ship's heading, ship's speed and position data collected during the Nella Dan Voyage 7 1986-87. This was a marine science voyage which also visited Davis. Data are available online via the Australian Antarctic Division Data Centre web page (see Related URL below). For further information, see the Marine Science Support Voyage Report at the Related URL below.

  • From December 2014 to February 2015, Geoscience Australia conducted a multibeam sonar survey (GA-0348) of the coastal waters around Casey station and the adjacent Windmill Islands. The survey utilised GA's Kongsberg EM3002D multibeam echosounder, motion reference unit and C-Nav differential GPS system mounted on the Australian Antarctic Division's (AAD) science workboat the Howard Burton. The survey was a collaborative project between GA, the AAD and the Royal Australian Navy (RAN). During the survey a total of approximately 27.3 square kilometres of multibeam bathymetry, backscatter and water-column data were collected, extending coverage of a RAN multibeam survey (survey number HI545) conducted the previous season (approximately 7 square kilometres). The regions covered extended seaward of Newcomb Bay and Clark Peninsula northwest of Casey Station, and seaward of Shirley and Beall Islands to the southwest. Complimentary datasets were also collected, including 18 drop video deployments to assess the benthic ecosystem composition and 39 sediment samples to ground-truth the seafloor substrate. Macroalgae spectral analyses were also collected to develop a spectral library for possible future satellite bathymetry investigations. The new high-resolution bathymetric grid (1 metre resolution) reveals seafloor features in the Casey area in unprecedented detail.

  • The composition, size and abundance of phytoplankton and microzooplankton were measured across a transect from Prydz Bay to Australia during late March 1987. Phytoplankton populations were low, with concentrations of chlorophyll a ranging from 0.08 to 0.22 mg.m-3. Small cells predominated numerically; nanoplankton consistently represented 55 to 68% of the total cell number while picoplankton represented 27 to 44%. Microplankton never represented more than 3% of cells by number, but constituted 57 to 93% of the total cell volume, and accounted for most of the latitudinal variation in total volume. Small flagellates, not identifiable by light microscopy, were the most numerous cells encountered across the transect, with a five-fold increase in abundance at 47S. Numbers of diatoms (most less than 20 microns in size) increased markedly south of the Antarctic Convergence, with a strong correlation to the concentration of silica. Dinoflagellate numbers were relatively constant across the transect, although somewhat higher north of 50S. Those less than 20 microns in size were most numerous and accounted for most of the numerical variation. HPLC analysis of chlorophyll and carotenoid pigments showed a peak of peridinin which coincided with the flagellate peak at 47S, but not with observed dinoflagellates, suggesting that the flagellate peak included unrecognized dinoflagellates. Chlorophyll b and prasinoxanthin were also associated, suggesting a significant contribution by prasinophytes. Almost no cyanobacteria were observed south of the convergence, although very large numbers, which correlated with the abundance of zeaxanthin, were encountered to the north. Numbers of ciliates and tintinnids were quite variable although they followed each other closely. Numbers of both were low in the region of the Antarctic Convergence.

  • We collected surface seawater samples using trace clean 1L Nalgene bottles on the end of a long bamboo pole. We will analyse these samples for trace elements. Iron is the element of highest interest to our group. We will determine dissolved iron and total dissolvable iron concentrations. Samples collected from 7 sites: Sites 1, 2, 3, 4 were a transect perpendicular to the edge of the iceberg to try and determine if there is a iron concentration gradient relative to the iceberg. Sites 4, 5, 6 were along the edge of the iceberg to determine if there is any spatial variability along the iceberg edge. Site 7 was away from the iceberg to determine what the iron concentration is in the surrounding waters not influenced by the iceberg.

  • The RAN Australian Hydrographic Service conducted hydrographic survey HI290 at Heard Island, February to March 1997. The survey dataset, which includes the Report of Survey, was provided to the Australian Antarctic Data Centre by the Australian Hydrographic Office and is available for download from a Related URL in this metadata record. The survey was lead by LT R.D.Bowden. The spatial extent given in this metadata record is that of Heard Island as the spatial extent of the survey is unknown to the Australian Antarctic Data Centre. The data are not suitable for navigation.

  • Three Trident Sensors Helix beacons (Unit 1,2,3) were deployed about on ice floes close to latitude 62.8 S and longitude 29.8 E on 4th July 2017 to measure sea ice drift. The region where the instruments were deployed (Antarctic Marginal Ice Zone) consisted of first-year ice on average ~50 cm thick. The instruments were deployed by hand by three people, lowered by crane from the ship to the ice on a basket cradle on floes ~5 m in diameter. The temporal resolution is 4 hours. The survival of the sensors depended on staying fixed to the floe and the battery life. Unit 1 provided GPS location from the 5th July 2017 to 1st December 2017, started at 62.84 S and 30.20 E and finished at 61.55 S and 55.99 E. Unit 2 provided GPS location from the 5th July 2017 to 3rd August 2017, started at 62.83 S and 30.20 E and finished at 62.36 S and 31.57 E. Unit 3 provided GPS location from the 5th July 2017 to 15st August December 2017, started at 62.59 S and 29.98 E and finished at 61.16 S and 35.60 E. In the .xlsx submission sheet 1 refers to Unit 1, sheet 2 to Unit 2, and sheet 3 to Unit 3. First column is the Unit Identifier (1,2,3) Second column is the date in the format day/month/year Third column is the UTC time in the format hh:mm:ss Fourth column is the latitude in degrees and decimals, the negative refers to South Fifth column is the longitude in degrees and decimals, the positive refers to East