This dataset contains acoustic recordings from Directional Frequency Analysis and Recording (DIFAR) sonobuoys that were deployed from 30 January – 23 March 2021 during the TEMPO voyage. 251 sonobuoys were deployed yielding 460 hours of acoustic recordings. Three models of sonobuoys were used during the voyage: AN/SSQ-53F sonobuoy from SonobuoyTechSystems, USA (made in 2011; identifiable by tall black housing); Q53F sonobuoys from Ultra Electronics Australia (made in 2011 for Australian Defence; identifiable by tall silver housing); SDSQ955 (HIDAR) sonobuoys from Ultra Electronics UK (re-lifed in 2018; identifiable from small silver housing); During TEMPO, recordings were made by deploying above sonobuoys in DIFAR (standard) mode while the ship was underway (Gedamke and Robinson 2010, Miller et al. 2015). During transit, listening stations were conducted every 30 nmi in water depths greater than 200 m when Beaufort sea state was less than 7. Sonobuoys were occasionally deployed with spacing less than 30 nmi in an attempt to more precisely determine spatial extent and vocal characteristics of calls that were believed to be coming from animals relatively close to the ship’s track. During marine science stations, sonobuoys were deployed approximately 2-4 nmi prior to stopping in order to attempt to monitor them for the full six-eight hour duration of their operational life or the duration of the station. The sampling regime was chosen for compatibility with previous surveys, and to balance spatial resolution with the finite number of sonobuoys available for this study. Instrumentation, software, and data collection At each listening station, a sonobuoy was deployed with the hydrophone set to a depth near 140 m. Sonobuoys transmitted underwater acoustic signals from the hydrophone and directional sensors back to the ship via a VHF radio transmitter. Radio signals from the sonobuoy were received using an omnidirectional VHF antenna (PCTel Inc. MFB1443; 3 dB gain tuned to 144 MHz centre frequency) and a Yagi antenna (Broadband Propagation Pty Ltd, Sydney Australia) mounted on the aft handrail of the flying bridge. The antennas were each connected to a WiNRADiO G39WSBe sonobuoy receiver via low-loss LMR400 coaxial cable via a cavity filter with 1 MHz passband centered on 144 MHz. The radio reception range on the Yagi antenna was similar to previous Antarctic voyages, and was adequate for monitoring and localisation typically out to a range of 10-12 nmi, provided that the direction to the sonobuoy was close (i.e. within around 30o) to the main axis of the antenna. The radio reception on the omnidirectional antenna typically provided 5-10 nmi of omnidirectional reception from sonobuoys. At transit speed (8-11 knots), the Yagi antenna provided about 75 minutes of acoustic recording time per sonobuoy. Using both antennas together were able obtain radio reception for up to six hours (i.e. the maximum life of a 955 sonobuoy) when sonobuoys were deployed within 5 nmi of a marine science station. Received signals were digitised via the instrument inputs of a Fireface UFX sound board (RME Fireface; RME Inc.). Digitised signals were recorded on a personal computer as 48 kHz 24-bit WAV audio files using the software program PAMGuard (Gillespie et al. 2008). Data from both the Yagi and Omnidirectional antenna were recorded simultaneously as WAV audio channels 0 (left) and 1 (right). Each recorded WAV file therefore contains a substantial amount of duplication since both antennas and receivers were usually receiving the same signals from the same sonobuoy. Directional calibration The magnetic compass in each sonobuoy was not calibrated/validated upon deployment because the ship did not generate enough noise. Intensity calibration Intensity calibration and values followed those described in Rankin et al (2019). Sonobuoy deployment metadata The PAMGuard DIFAR Module (Miller et al. 2016) was used to record the sonobuoy deployment metadata such as location, sonobuoy deployment number, and audio channel in the HydrophoneStreamers table of the PAMGuard database (IN2021_V01_Difar-2021-01-22.sqlite3). A written sonobuoy deployment log (SonobuoyLog.pdf) was also kept during the voyage, and this includes additional notes and additional information not included in the PAMGuard Database such as sonobuoy type, and sonobuoy end-time. Real-time monitoring and analysis: Aural and visual monitoring of audio and spectrograms from each sonobuoy was conducted using PAMGuard for at least 5 minutes after deployment only to validate that the sonobuoy was working correctly. Additional information about sonobuoys is contained in the file: Sonobuoy data collection during the TEMPO voyage - 2021-01-15.pdf References Greene, C.R.J. et al., 2004. Directional frequency and recording ( DIFAR ) sensors in seafloor recorders to locate calling bowhead whales during their fall migration. Journal of the Acoustical Society of America, 116(2), pp.799–813. Miller, B.S. et al., 2016. Software for real-time localization of baleen whale calls using directional sonobuoys: A case study on Antarctic blue whales. The Journal of the Acoustical Society of America, 139(3), p.EL83-EL89. Available at: http://scitation.aip.org/content/asa/journal/jasa/139/3/10.1121/1.4943627. Miller, B.S. et al., 2015. Validating the reliability of passive acoustic localisation: a novel method for encountering rare and remote Antarctic blue whales. Endangered Species Research, 26(3), pp.257–269. Available at: http://www.int-res.com/abstracts/esr/v26/n3/p257-269/. Rankin, S., Miller, B., Crance, J., Sakai, T., and Keating, J. L. (2019). “Sonobuoy Acoustic Data Collection during Cetacean Surveys,” NOAA Tech. Memo. NMFS, SWFSC614, 1–36.

This indicator is no longer maintained, and is considered OBSOLETE. INDICATOR DEFINITION Measurements of sea surface temperature 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 temperature. 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 temperature 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 temperature from Antarctic supply ships. The best spatial coverage of sea surface temperature is provided by satellites, due to extensive cloud cover in the Southern Ocean and biases in the satellite measurement, in situ observations of sea surface temperature are necessary. RESEARCH ISSUES Sea surface temperature 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 temperature in the Southern Ocean. LINKS TO OTHER INDICATORS Sea ice extent and concentration Chlorophyll concentrations Sea surface salinity

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.

The RAN Australian Hydrographic Service conducted hydrographic survey HI176 at Macquarie Island in December 1993. The main survey area was adjacent to the north-east coast between North Head and The Nuggets. Survey lines were also followed part way down the west coast of the island and in the vicinity of Judge and Clerk Islets and Bishop and Clerk Islets. The survey dataset, which includes metadata, 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 A.J.Withers. The data are not suitable for navigation.

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.

The AADC (Australian Antarctic Data Centre) is in the process of converting all internally held spatial datasets to the ITRF2000 horizontal datum. This consolidated dataset consists of surveys HI623_alatB_gg, HI625_alatB_GG, HI632_alat_B_gg, HI632_alat_C_gg, LADSII_MMI20756_HSDB_T0001_SD_100029052_op, LADSII_MMI20756_HSDB_T0001_SD_100029053_op, LADSII_MMI20756_HSDB_T0001_SD_100029054_op converted to ITRF2000 horizontal datum with Z conversion values for multiple height datums. The data was provided to the AAD by Paul Digney of Jacobs consulting in March 2021. Included survey datasets: • HI623_alatB_gg • HI625_alatB_GG • HI632_alat_B_gg • HI632_alat_C_gg • LADSII_MMI20756_HSDB_T0001_SD_100029052_op • LADSII_MMI20756_HSDB_T0001_SD_100029053_op • LADSII_MMI20756_HSDB_T0001_SD_100029054_op All data are in horizontal datum ITRF2000 and have been combined into a single ESRI geodatabase feature class titled AHS_Surveys_Macca_ITRF2000. Attribute data shows quality information, conversion factors (shift in metres) for multiple datums and the MSL orthometric height: Column Name Alias Meaning Easting Easting Easting ITRF2000 Northing Northing Northing ITRF2000 LAT_to_GRS LAT_to_GRS LAT (Chart Datum) to GSR80 LAT_to_Mac LAT_to_Mac LAT to Macca MSL Z_To_GRS80 Z_To_GRS80 Height to the Ellipsoid Z_To_Macca Z_To_Macca Local MSL orthometric height Vertical_U Vertical_U How good is the Vertical Position Horizontal Horizontal How good is the Horizontal Position Uncertaint Uncertaint Uncertainty Comments Depth_Comm Depth_Comments Vertical uncertainty ranges from 0.5 to 1.2 m and horizontal uncertainty ranges from 2 to 5.5 m. Null values indicate unknown uncertainty. See the attached document ‘Metadata_Record_Macqaurie Island Final.xlsx’ for further details.

A database containing sounding data around Macquarie Island. Track line data for each data source is included.

This dataset contains bathymetry (water depth), ship's heading, ship's speed and position data collected during the Nella Dan Voyage 4 1987-88. This was the Nella Dan's final voyage. Some marine science was carried out en route to Macquarie Island from Hobart. Data are available online from 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.

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.

This is a parent record for data collected from AAS project 4102. Project 4102 also follows on from ASAC project 2683, "Passive acoustic monitoring of antarctic marine mammals" (see the related metadata record at the provided URL). Public Summary: Half a century ago the Antarctic blue whale was perilously close to extinction. Over 350,000 were killed before the remaining few were fully protected. A decade ago this elusive and poorly understood species was estimated to be less than 5% of its pre-whaling abundance. This multi-national, circumpolar project will develop and apply powerful new techniques to survey these rare whales and gain an insight into their recovery and ecology. The project is the flagship of the Southern Ocean Research Partnership - an International Whaling Commission endorsed collaborative program.