Contact for the resource

AU/AADC > Australian Antarctic Data Centre, Australia

1708 record(s)
Type of resources
Contact for the resource
Provided by
From 1 - 10 / 1708
  • During the 2013 Antarctic Blue Whale Voyage Acousticians noted all whale calls and other acoustic events that were detected during real-time monitoring in a Sonobuoy Event Log. The acoustic tracking software, difarBSM, stored processed bearings from acoustic events and cross bearings in tab delimited text files. Each event was assigned a classification by the acoustician, and events for each classification were stored in separate text files. The first row in each file contains the column headers, and the content of each column is as follows: buoyID: Buoy ID number is the number of the sonobuoy on which this event was detected. This can be used as a foreign key to link to the sonobuoy deployment log. timeStamp_matlabDatenum: Date and time (UTC) at the start of the event represented as a Matlab datenum (i.e. number of days since Jan 0 0000). Latitude: Latitude of the sonobuoy deployment in decimal degrees. Southern hemisphere latitudes should be negative. Longitude: Longitude of sonobuoy deployment in decimal degrees. Western hemisphere longitudes should be negative. Altitude: Depth of the sonobuoy deployment in metres. For DIFAR sonobuoys either 30, 120 or 300. magneticVariation_degrees: The estimated magnetic variation of the sonobuoy in degrees at the time of the event. Positive declination is East, negative is West. At the start of a recording this will be entered from a chart. As the recording progresses, this should be updated by measuring the bearing to the vessel. bearing_degreesMagnetic: Magnetic bearing in degrees from the sonobuoy to the acoustic event. Magnetic bearings were selected by the acoustician by choosing a single point on the bearing-frequency surface (AKA DIFARGram) produced by the analysis software difarBSM. frequency_Hz: The frequency in Hz of the magnetic bearing that the acoustician selected from the bearing-frequency surface (DIFARGram). logDifarPower: The base 10 logarithm of the height of the point on the DIFARGram receiveLevel_dB: This column contains an estimate of the The RMS receive level (dB SPL re 1 micro Pa) of the event. Received levels were estimated by applying a correction for the shaped sonobuoy frequency response, the receiver’s frequency response, and were calculated over only the frequency band specified in each classification (see below). soundType: soundType is the classification assigned to the event by the acoustician. Analysis parameters for each classification are included in the csv file classificationParameters.txt. The columns of this file are as follows: outFile: The name of the tab-separated text file that contains events for this classification. analysisType: A super-class describing the broad category of analysis parameters soundType: The name of the classification sampleRate: When events are processed, they are downsampled to this sample rate (in Hz) in order to make directional processing more efficient and precise FFTLength: The duration (in seconds) used for determining the size of the FFT during difar beamforming (i.e. creation of the DIFARGram). numFreqs: Not used during this voyage targetFreq: The midpoint of the frequency axis (in Hz) displayed in the DIFARGram Bandwidth: This describes the half-bandwidth (Hz) of the frequency axis of the DIFARGram. The frequency axis of the DIFARGram starts at targetFreq-bandwidth and ends at targetFreq + bandwidth frequencyBands_1: The lower frequency (Hz) used for determining RMS received level. frequencyBands_2: The upper frequency (Hz) used for determining RMS received level. preDetect: Duration of audio (in seconds) that will be loaded before the start of the event. The processed audio includes the time-bounds of the event marked by the acoustician as well as preDetect seconds before the start of the event. postDetect: Duration of audio (in seconds) that will be loaded after the end of the event. The processed audio includes the time-bounds of the event marked by the acoustician + postDetect seconds.

  • This is the CTD data set from RV Tangaroa cruise tan0803, 26th March to 26th April 2008, along the Macquarie Ridge. This was the recovery cruise for the Macquarie Ridge mooring array. The primary aims of the oceanographic program were: 1. recovery of a New Zealand/Australia collaborative mooring array spanning two gaps in the Macquarie Ridge north of Macquarie Island, and 2. occupation of a CTD transect running south from New Zealand to 60o S along the Macquarie Ridge. Eight of the nine moorings were successfully recovered. The mooring at site number 3 (NIWA gear) was unrecoverable, with acoustic release communication indicating only the bottom portion of the mooring remaining and lying flat on the ocean floor. Complete details of the mooring work are included in a separate mooring recovery report. Mooring instruments were downloaded on the ship, with a very high percentage of successful data recording. Ship maneouvering and deck operations all went well throughout the recoveries. Shiptime at the mooring locations was well spent, with daylight hours dedicated to mooring recovery, and night time used for nearby CTD, swath mapping, coring and sea mount activities, and for unspooling of mooring line. The additional container space created on the top deck portside (above the trawldeck) proved extremely valuable for stowage of mooring gear. 58 CTD's were completed during the cruise, including 54 along the main transect, and 4 at coring locations (part of the geology program). Main transect CTD's included 2 across the northern mooring group, and 3 across the southern mooring group. Most casts were to within 25 metres of the bottom. Instrument problems resulted in incomplete casts at the following locations: CTD 9, CTD 11 and CTD 27. CTD 46 was skipped due to bad weather, while further instrument problems prevented a cast at the southernmost site (CTD 50). Niskin bottles were sampled at each station for dissolved oxygen and salinity, with a subset of stations selected for 18O sampling. Some stations were additionally sampled for DIC, alkalinity, 13C, silicate, and U/Th, as part of the geology program. Note that dissolved oxygen data have been removed from this data set, as oxygen bottle samples were never analysed.

  • The ‘Logger’ data entry system was developed by the International Fund for Animal Welfare (IFAW) and is a flexible system to record information during a voyage. This system was the primary data entry system for the voyage and all events were recorded in Logger’s database. The logger access database contains all data collected throughout the Antarctic blue whale voyage related to: Observer effort (effort status, event, number of observers and locations, ship guide and data logger) Cetacean sightings and resightings (time, sighting number, sighting platform, estimate distance, binocular reticles, angle, species, sighting cue, heading, estimate of number of individuals, observer of sighting, behaviour, pod compaction, comments) Sonobuoy deployments (time, sonobuoy number, notes) Environmental observations (sightability, sea state, swell, weather, cloud cover, visibility, intensity, glare, ice, sea surface temperature) GPS data (time indexed NMEA feed) CTD deployments (time, notes) Biopsy events (time, success, sample number, reaction, attempts, dart recovery, notes)

  • A mathematical model (Bennetts and Meylan, 2021, has been used to make predictions of ocean wave transfer to Ross Ice Shelf flexure. The transfer is considered along transects of the Ross Ice Shelf and adjoining open ocean, where the ice shelf thickness and seabed profiles along the transects are sampled from the Bedmap2 dataset (Fretwell et al, 2013, Our dataset consists of MAT-files, where each file is for a particular transect and holds two structures: 'data_I' as input data and 'data_o' for the model output data. The input data are the profiles from Bedmap2: 'thick' is the shelf thickness, 'draft' is the shelf draught; and 'bed' is the seabed elevation. They are all in vector form with 2001 sample points along the shelf, which was found to give model outputs accurate to 95%. The input data also contains: a 1x2 vector 'L_vec', for which the first entry is the shelf length, and the second entry is the length of the adjoining open ocean, where both values are in metres; and a 1x2 vector 'Int_vec', for which the first entry is the total number of sample points (ocean + shelf) and the second entry is the number of points in the shelf only. The output date are the three matrices where the rows correspond to different wave period and columns are distances along the transect: 'eta_w' is the water displacement (dimensionless); 'eta_s' is the shelf displacement (dimensionless); and 'str' is the flexural shelf strain (1/metres). All three outputs are normalised by the incident amplitude, noting that the model is linear. The output data also contains: a 1x300 vector containing the wave periods 'T', which are log-spaced between 10s and 1000s. The data are divided into two folders: validation/ and transects/. The first group (validation/) are used to validate the model predictions against the observations of Chen et al (Geophysical Research Letters, 2019, close to 2 km away from the shelf front, where the results of Chen et al (2019) have been digitised and are contained in 'Chen_paper.mat'. The second group (transects/) can be used to study transfer over a 500km wide region of the Ross Ice Shelf. There are 101 transects with 5 km spacing. We also analysed the shelf displacement and strain over different wave periods at 10 km away from shelf front for all transects to investigate the relations between strain and wave period, these data have stored in 'Transfer_function_x_10km.mat'. Three MATLAB scripts (Fig1.m, Fig2.m, Fig3.m) are included to recreate results from Bennetts et al (submitted). Fig1.m produces plots from observation (Chen et al) and our models. Fig2.m performs strain transfer function analysis for different profiles and Fig3.m generate the strain map and selected region of Ross Ice Shelf for given incident ocean wave. For Fig1.m, it requires “Bedmap2 Toolbox for Matlab” to access the bedmap2 for producing Ross Ice Shelf on the Antarctica map. A link to download this software will be stated in the MATLAB scripts. An updated dataset was provided on 2022-10-25.

  • A Langrangian free drift model is developed, including a term for geostrophic currents that reproduces the 13 h period signature in the ice motion observed in the data (CLSC_WIIOS_2017; parent data). The calibrated model is shown to provide accurate predictions of the ice drift for up to 2 days, and the calibrated parameters provide estimates of wind and ocean drag for pancake floes under storm conditions. Model setup is described in "Drift of pancake ice floes in the winter Antarctic marginal ice zone during polar cyclones", Alberello et. al [; pre-print]. The dataset includes model data. Six model outputs are included. (i) "full_t00" includes the full 10 days simulation, with all the forcing switched on (ii) "noge_t00" includes the full 10 days simulation, but the geostrophic current is suppressed (iii) "full_t25_noup" includes the simulation with start at 2.5 days, all the forcing switched on, no update of the drag coefficients (iv) "full_t25_newn" includes the simulation with start at 2.5 days, all the forcing switched on, the drag coefficients are recalibrated (v) "full_t50_noup" includes the simulation with start at 5 days, all the forcing switched on, no update of the drag coefficients (vi) "full_t50_newn" includes the simulation with start at 5 days, all the forcing switched on, the drag coefficients are recalibrated In each file: - rho_a the air density (1.3 kg/m3) - rho_w the water density (1028 kg/m3) - rho_i the ice density (910kg/m3) - C_w the water drag coefficient (calibrated) - C_a the air drag coefficient (calibrated) - turn the turning angle (25 degrees) - Nansen the Nansen number evaluated using C_a and C_w - aalpha a model parameter (proportional to air and ice parameters) - abeta a model parameter (proportional to water and ice parameters) - ag amplitude of the geostrophic current (U_g=0.125m/s) - tg initial phase of the geostrophic current (in radians) - to start time (in matlab format, use "datestr(to)" ), after which model resolution is 60 seconds - wo components of wind in the East and North direction (m/s) - wi components of wind in the East and North direction (m/s) - uo components of modelled ice drift speed in the East and North direction (m/s) - lo longitude and latitude of modelled ice position (degrees) - xo position of modelled ice in the East and North direction (m), given with respect to the initial position (0,0) - wco components in the East and North direction of geostrophic current (m/s)

  • These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Ice Bird Dates in ice: 19 Mar 1988 - 29 Mar 1989 Observers: Jeff Wilson Summary of voyage track: 19/3 Observations started at Davis station 68d11mS 76d23mE 19-25/3 Steamed west from Davis to Mawson 27/3 Some observations north of Mawson toward ice edge The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

  • Oceanographic measurements were conducted in the Subantarctic Zone south of Tasmania in September 1997. 5 sediment trap moorings were deployed, and a total of 10 CTD vertical profiles were taken. Over 90 Niskin bottle water samples were collected for the measurement of salinity and nutrients (phosphate, nitrate+nitrite, silicate). The fields in this dataset are: oceanography ship station number date start time bottom time finish time cruise start position bottom position finish position maximum position bottom depth pressure temperature (T-90) salinity sigma-T specific volume anomaly geopotential anomaly dissolved oxygen fluorescence photosynthetically active radiation

  • Metadata record for data from AAS (ASAC) project 3010. Public Pycnogonids are primitive, bizarre arthropods. Found worldwide, Antarctic pycnogonids are the most diverse, abundant, and include some of the most spectacular forms. Near 250 species from the region are known, many in need for taxonomic revision, and more species new to science likely to be found. This project will document diversity of pycnogonids and target widely distributed species to obtain morphological, genetic and ecological information on distribution patterns and evolutionary history. This combined approach should provide a better insight of the roles of sea spiders in Antarctic biodiversity and the evolution and radiation of Antarctic marine benthic fauna. Project objectives: 1. To document the diversity of Australian Antarctic pycnogonids at species level and to target species with potential to investigate ecological interactions, zoogeographical patterns and genetic variability. 2. To examine connectivity patterns and genetic differentiation in populations of target species of pycnogonids across large spatial scales inferring diversification processes and possibly speciation rates. 3. To investigate the distribution patterns and possible mechanisms of dispersal of species with apparent wide distributions (e.g. circumpolar distribution, Antarctic -Pacific distribution and Antarctic-Arctic), based on molecular tools. 4. To explore how sea spiders fit evolutionary models testing the origin of deep sea fauna and proposing hypothesis for colonisation mechanisms and radiation processes, as many pycnogonid taxa from the deep sea are also represented on the continental shelf. 5. To resolve phylogenetic questions regarding the affinities among Antarctic species and lower latitude species to understand the evolutionary history of a highly diverse and cosmopolitan lineage (Callipallenidae-Nymphonidae). Details from previous years are available for download from the provided URL. Taken from the 2009-2010 Progress Report: Objective 1 - During this second year of the project more than 500 lots of unsorted samples of pycnogonids are being sorted and identified, many to species level. -In July 2009, 130 lots from the Ross Sea and Subantarctic areas deposited at NIWA in NZ, were sorted, identified and many of them barcoded. Some material has been requested on loan to continue taxonomic studies probably leading to description of new species. -In November 2009, more than 330 lots of CEAMARC samples of sea spiders were received on loan from the Natural History Museum in Paris, where they were deposited in 2008. This material is extremely relevant not only for its diversity but also numbers of individuals per sample. CEAMARC samples (including additional 136 samples from AAD) have provided a unique opportunity to obtain appropriate numbers of individuals of target species such Nymphon australe, with more than 1000 individuals collected. This material is currently being used in analyses about genetic differentiation and diversity at different spatial scales. -Current work in progress on the species level identification of the CEAMARC material would lead to a proper characterisation of the pycnogonid fauna from an extremely important area of the Australian Antarctic territory. We have identified Nymphon australe, Colossendeis megalonyx, Nymphon spp., Austropallene spp. and Pallenopsis spp, as the most frequent and abundant Australian Antarctic pycnogonids and it is expected to correlate abundance and occurrence patterns to other biotic and abiotic parameters that could explain the numbers and diversity of these taxa in the area. - I co-authored a pioneering paper with H. Griffiths (senior author) from BAS and others, on the diversity and biogeography of Antarctic pycnogonids, which was submitted last month to journal Ecography. - At least two new species to science are to be described based on CEAMARC material currently studied. Objective 2 -There is a publication in press (Arango et al.) in the journal Deep-Sea Research II presenting a genetic analysis of the most abundant Antarctic sea spider species Nymphon australe. The study includes 131 individuals of N. australe collected from Antarctic Peninsula, Weddell Sea and East Antarctica. -Additional material of N. australe from CEAMARC made available by MNHN in Paris is currently being analysed to expand the published study and focus on the possible explanations for such wide distribution of a species with apparent limited dispersal capabilities. - Just recently, I established research collaboration with Dr. F. Leese at Ruhr University Bochum, Germany, who is currently interested in the population genetics and genetic connectivity of Antarctic sea spiders. This collaborative effort should prove to be very successful in terms of geographic cover of samples, molecular markers used and analyses implemented. Objective 3 -The paper in press mentioned above addresses the question of circumpolarity of N. australe and finds it might be one of the few 'true' circumpolar species given that the dataset does not reflect cryptic speciation. Preliminary data for other species are showing contrasting results and might reflect 'unknown' species considered cryptic or perhaps just reflects necessity of fine detail taxonomy--. This work on Colossendeis megalonyx is partly in collaboration with Leese's team in Germany. -Material from New Zealand, Tasmania and NSW are currently used for analysis on phylogenetic affinities between Antarctic and non-Antarctic taxa, and also to compare patterns of genetic differentiation among different habitats and taxa. Achelia species distributed from Antarctica to tropical areas will be looked at in a future project depending on funding. Objective 4 -Objective 4 part of a proposal submitted to Australian Biological Resources Study (ABRS) to study deep phylogeny and divergence times of Pycnogonida to understand evolutionary links between Antarctic, deep-sea and Australian shallow waters species, in collaboration with J. Strugnell. During the first and second year of the project advances have been made in terms of literature review, discussion with specialists and most importantly acquisition of material for molecular work that will complement the dataset published in 2007 (Arango and Wheeler 2007). Objective 5 - Since September 2009 I have been actively working on constructing datasets for phylogenetic analyses of Nymphon, the most diverse and abundant taxon of sea spiders in the world, and their closest relatives, the callipallenids, with centre of diversity in Australasia. I am working on including morphological and molecular characters for as many representative species as possible. So far, 30 species are included, and at least 50 morphological are being scored. More species are desired, so I am permanently seeking donation of material, collaborations, etc. the genes COI and 16S are sequenced for at least 50% of the samples included so far, I am currently investigating other molecular markers that might be suitable to resolve a phylogeny at this level. - Given the availability of material from many different species of Colossendeidae, and the relevance and impact of this group --being the family of the giant sea spiders, I am currently collecting material (i.e. tissue samples, DNA sequences, morphological descriptions) to work on the phylogeny of this cosmopolitan family with more than 40 species in the Southern Ocean. At least 15 species have been sequenced so far. The same techniques and methodology as for the Nymphon phylogeny are being applied.

  • These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: Australia Vessel: Aurora Australis Dates in ice: 3 Dec 1990 - 5 Dec 1990 Observers: Ian Allison Summary of voyage track: 3/12 Ice edge at 63d52mS, 79d56mE 3-5/12 Vessel steamed from ice edge to Mawson The fields in this dataset are: SEA ICE CONCENTRATION SEA ICE FLOE SIZE SEA ICE SNOW COVER SEA ICE THICKNESS SEA ICE TOPOGRAPHY SEA ICE TYPE RECORD DATE TIME LATITUDE LONGITUDE OPEN WATER TRACK SNOW THICKNESS SNOW TYPE SEA TEMPERATURE AIR TEMPERATURE WIND VELOCITY WIND DIRECTION FILM COUNTER FRAME COUNTER FOR FILM VIDEO RECORDER COUNTER VISIBILITY CODE CLOUD WEATHER CODE COMMENTS

  • Metadata record for data from AAS (ASAC) project 3046. Public The overall objective is to characterise the response of Southern Ocean calcareous zooplankton to ocean acidification resulting from anthropogenic CO2 emissions. Simulated increases in anthropogenic CO2 suggest a reduction in the calcification rates of calcareous organisms. A change in the calcification in the Southern Ocean may cause marine ecosystem shifts and in turn alter the capacity for the ocean to absorb CO2 from the atmosphere. We plan to take advantage of naturally-occurring, persistent, zonal variations in Southern Ocean primary production and biomass to investigate the effects of CO2 addition from anthropogenic sources on Southern Ocean calcareous zooplankton communities. A download file containing an excel spreadsheet of data can be found at the provided URL. Project objectives: The overall objective of this project is to characterise the impacts of recent, primarily anthropogenic, increases in atmospheric CO2 and related changes in the carbonate chemistry on shell formation by calcareous zooplankton in the Australian sector of the Southern Ocean. Calcareous zooplankton (e.g. planktonic foraminifera and pteropods) will be collected using plankton nets at five Southern Ocean localities during high seasonal flux periods. Planktonic foraminiferal and pteropod species and abundances, calcification rates and geochemistry (stable isotope and trace-metal) will be determined on plankton tow samples. Data from recent plankton tow samples will be compared with data deposited historically in the Southern Ocean and recovered from existing deep ocean sediment cores to provides insights about the extent to which modern carbon conditions may have already generated ecological impacts. The project will also provide a baseline of the present-day impact of ocean acidification and can be used to monitor the influence of future anthropogenic CO2 emissions in Southern Ocean ecosystems. Taken from the 2008-2009 Progress Report: Progress against objectives: Because of logistical delays to the Aurora Australis shipping schedule, ship time for this project was deferred to the 2009/2010 season. We have made progress in analysing other materials form previous voyages which will assist in the sampling design for the upcoming season. We are making good progress in planning the upcoming voyage currently scheduled for late 2009. Taken from the 2009-2010 Progress Report: Progress against objectives: Project scientists participated in Voyage 2 of the Aurora Australis, from Hobart to Casey Station in December 2009. Using the Rectangular Midwater Trawl we collected a total of eight plankton samples for examination of calcareous plankton distribution and shell characteristics in the summer Southern Ocean. We were targeting pteropods and planktonic foraminifera, two sets of calcifiers whose calcification response to ocean acidification we had previously reported on in publications in Nature Geoscience, Biogeosciences Discussions, and Deep-Sea Research Part II (in press). Project participants included collaborators from Australian National University and Scottish Natural Heritage, UK. There were low abundance of planktonic calclfiers in this particular seasons and sector, but we consider the initial collection a god start. Samples included approx. 18 pteropods; other samples are still being held by Biosecurity Australia and will be examined as soon as they are released. Other samples have already been sent to researchers at the Australian Institute of Marine Science for genetic (RNA) sequencing. This latter collaboration is a key one which will help answer questions about evolutionary responses to ocean acidification; if there are genotypes which are more or less vulnerable to acidification we may already be seeing selective pressure in the ecosystem and a change in the structure of assemblages as "winners" and "losers" are differentially affected by the impact.