EARTH SCIENCE > OCEANS > SEA ICE > ICE FLOES
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Raw GPS and ship motion data collected during the Antarctic Circumnavigation Expedition 2016/2017. Waves in the Southern Ocean are the biggest on the planet. They exert extreme stresses on the coastline of the Sub-Antarctic Islands, which affects coastal morphology and the delicate natural environment that the coastline offers. In Antarctic waters, the sea ice cover reflects a large proportion of the wave energy, creating a complicated sea state close to the ice edge. The remaining proportion of the wave energy penetrates deep into the ice-covered ocean and breaks the ice into relatively small floes. Then, the waves herd the floes and cause them to collide and raft. There is a lack of field data in the Sub-Antarctic and Antarctic Oceans. Thus, wave models are not well calibrated and perform poorly in these regions. Uncertainties relate to the difficulties to model the strong interactions between waves and currents (the Antarctic Circumpolar and tidal currents) and between waves and ice (reflected waves modify the incident field and ice floes affect transmission into the ice-covered ocean). Drawbacks in wave modelling undermine our understanding and ability to protect this delicate ocean and coastal environment. By installing a Wave and Surface Current Monitoring System (WaMoS II, a marine X-Band radar) on the research vessel Akademic Thresnikov and using the meteo-station and GPS on-board, this project has produced a large database of winds, waves and surface currents. Dara were collected during the Antarctic Circmumnavigaion Expedition, which took place from Dec. 2016 to Mar. 2017. The instrumentation operated in any weather and visibility conditions, and at night, monitoring the ocean continuously over the entire Circumnavigation. Records can support 1. the assessment of metocean conditions in the Southern Oceans; and 2. calibration and validation of wave and global circulation models. Data - AAS_4434_ACE_GPS contains basic metereological conditions acquired form the ship’s meteo-station, gepgraphical coordinates (latitude, longitude and altitude) from the ship’s GPS and ship motion data from the ship’s Inertial Measurement Unit (IMU). These data are stored as time series with a sampling frequency of 1Hz.
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Although the floating sea ice surrounding the Antarctic damps ocean waves, they may still be detected hundreds of kilometres from the ice edge. Over this distance the waves leave an imprint of broken ice, which is susceptible to winds, currents, and lateral melting. The important omission of wave-ice interactions in ice/ocean models is now being addressed, which has prompted campaigns for experimental data. These exciting developments must be matched by innovative modelling techniques to create a true representation of the phenomenon that will enhance forecasting capabilities. This metadata record details laboratory wave basin experiments that were conducted to determine: (i) the wave induced motion of an isolated wooden floe; (ii) the proportion of wave energy transmitted by an array of 40 floes; and (iii) the proportion of wave energy transmitted by an array of 80 floes. Monochromatic incident waves were used, with different wave periods and wave amplitudes. The dataset provides: (i) response amplitude operators for the rigid-body motions of the isolated floe; and (ii) transmission coefficients for the multiple-floe arrays, extracted from raw experimental data using spectral methods. The dataset also contains codes required to produce theoretical predictions for comparison with the experimental data. The models are based on linear potential flow theory. These data models were developed to be applicable to Southern Ocean conditions.
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These data were collected to provide a spatial context for activities on SIPEX-2. Please see the document 'SIPEX II ice floe surveying report' for more detail. Files generated and stored in this dataset will be familiar to users of Trimble and Leica GPS equipment, and the UNAVCO 'teqc' utility. Please refer to the relevant documentation from Leica, Trimble and UNAVCO. Total station data is extracted to comma separated point lists with either .csv of .asc extensions. The point code list is named 'totalstation.codelist.txt'. It also forms an appendix of the surveying report.
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WAMOS (marine radar) data collected during the Antarctic Circumnavigation Expedition (ACE, https://spi-ace-expedition.ch/), from December 2016 to March 2017. Waves in the Southern Ocean are the biggest on the planet. They exert extreme stresses on the coastline of the Sub-Antarctic Islands, which affects coastal morphology and the delicate natural environment that the coastline offers. In Antarctic waters, the sea ice cover reflects a large proportion of the wave energy, creating a complicated sea state close to the ice edge. The remaining proportion of the wave energy penetrates deep into the ice-covered ocean and breaks the ice into relatively small floes. Then, the waves herd the floes and cause them to collide and raft. There is a lack of field data in the Sub-Antarctic and Antarctic Oceans. Thus, wave models are not well calibrated and perform poorly in these regions. Uncertainties relate to the difficulties to model the strong interactions between waves and currents (the Antarctic Circumpolar and tidal currents) and between waves and ice (reflected waves modify the incident field and ice floes affect transmission into the ice-covered ocean). Drawbacks in wave modelling undermine our understanding and ability to protect this delicate ocean and coastal environment. By installing a Wave and Surface Current Monitoring System (WaMoS II, a marine X-Band radar) on the research vessel Akademic Thresnikov and using the meteo-station and GPS on-board, this project has produced a large database of winds, waves and surface currents. Dara were collected during the Antarctic Circmumnavigaion Expedition, which took place from Dec. 2016 to Mar. 2017. The instrumentation operated in any weather and visibility conditions, and at night, monitoring the ocean continuously over the entire Circumnavigation. Records can support 1. the assessment of metocean conditions in the Southern Oceans; and 2. calibration and validation of wave and global circulation models. Data - AAS_4434_ACE_WAMOS contains sea state conditions monitored continuously with a Wave and Surface Current Monitoring System (WaMoS II), a wave devise based on the marine X-Band radar (see Hessner, K. G., Nieto-Borge, J. C., and Bell, P. S., 2007, Nautical Radar Measurements in Europe: Applications of WaMoS II as a Sensor for Sea State, Current and Bathymetry. In V. Barale, and M. Gade, Sensing of the European Seas, pp. 435-446, Springer). Sea state consists of the directional wave energy spectrum, angular frequency and direction of propagation. Basic parameters such as the significant wave height (a representative measure of the average wave height), the dominant period, wavelength, mean wave direction, etc… were inferred from the wave spectrum. Surface current speed and the concurrent direction were also detected. Post processed data are available anytime the X-Band radar was operated in a range of 1.5NM; a full spectrum was generally obtained evert 20 minutes. Data are subdivided in: - WaMoS II frequency spectrum (1-D spectra) - WaMoS II wave number spectrum (2-D spectra) - WaMoS II frequency direction spectrum (2-D spectra) Data are quality controlled. ************************************************************************************************************** File informations Path to the spectra: \RESULTS\YYYY\MM\DD\HH\ : Year, month, day, hour. space\ : spatial mean results. single\ : raw spectra. mean\ : time averaged files. Header of the spectra: Additional information that might be needed for data analysis is stored in the headers. The output results generated using different WaMoS II software modules are separated by comment lines starting with ‘CC’. All headers are subdivided into: 1) Polar Header: including data acquisition parameters. 2) Car Header: including Cartesian transformation parameters. 3) Wave-Current Analysis Header: including wave and current analysis related parameters. There is a keyword of maximum 5 characters in each line of the header followed by some values and a comment, after the comment marker ‘CC’, describing the keyword. Values of missing parameters are set to -9, -9.0, -99.0, etc. depending on the data type. The 'end of header' keyword 'EOH', indicated the last line of the header section. ******************************************************************* WaMoS II frequency spectrum (1-D spectra): File Name: YYYY : Year. MM : Month. DD : Day. HH : Hour. MM : Minute. SS : Second. rigID : WaMoS II platform’s ID code (3 letters) Suffix: ’*.D1S’ : spatial mean of the spectra (that pass the WaMoS II internal quality control) averaged over WaMoS II analysis areas (up to 9) placed within the radar field of view. ‘*.D1M’ : temporal average spectra calculated using all spectra collected during the past dt=30 minutes of the time specified in the file. Time reference: CPU clock. Data Content: Frequency (f - Hz). Spectral energy (S(f) - m*m/Hz). Mean Wave Direction (MDIR(f) - deg), ���coming from’. Directional Spreading (SPR(f) - deg/Hz). ******************************************************************* WaMoS II wave number spectrum (2-D spectra): File Name: YYYY : Year. MM : Month. DD : Day. HH : Hour. MM : Minute. SS : Second. rigID : WaMoS II platform’s ID code (3 letters) Suffix: ’*.D2S’ : spatial mean of the spectra (that pass the WaMoS II internal quality control) averaged over WaMoS II analysis areas (up to 9) placed within the radar field of view. ‘*.D2M’ : temporal average spectra calculated using all spectra collected during the past dt=30 minutes of the time specified in the file. Time reference: CPU clock. Data Content: Spectral energy (S(kx,ky) - m*m/(Hz*rad)) as a function of wave number (kx and ky - rad/m). Data related header information MATRIX: Size of Matrix. DKX: Spectral resolution in Kx direction (2*Pi/m). DKY: Spectral resolution in Ky direction (2*Pi/m). ******************************************************************* WaMoS II frequency direction spectrum (2-D spectra): File Name: YYYY : Year. MM : Month. DD : Day. HH : Hour. MM : Minute. SS : Second. rigID : WaMoS II platform’s ID code (3 letters) Suffix: ‘*.FTH’ : spatial mean of the spectra (that pass the WaMoS II internal quality control) averaged over WaMoS II analysis areas (up to 9) placed within the radar field of view. ’*.FTM’ : temporal average spectra calculated using all spectra collected during the past dt=30 minutes of the time specified in the file. Time reference: CPU clock. Data Content: Spectral energy (S(f,θ) - m*m/(Hz*rad)) as a function of frequency (f – Hz) and direction (θ - deg). Data information Mf : number of frequency sampling points. Mth : number of direction sampling points. Data Matrix: Row 1 frequency sampling points, Column 1 direction sampling points. The dataset download also includes a file, "Available_Measurements", which is a general calendar that provides the list (day and time) of available measurements.
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These data were collected on the SIPEX II voyage of the Aurora Australis in 2012. These data are floe-scale maps of Antarctic sea ice draft (m). These were collected using a multibeam instrument attached to an autonomous underwater vehicle (AUV). This AUV was the WHOI 'SeaBED-class' vehicle named 'Jaguar'. Details on the deployment and processing of this data can be found in Williams, Maksym and Wilkinson et al., 2014 (Nature Geoscience). Data are provided for SIPEX-II stations 3, 4 and 6. Station 3: October 3 2012, located at 121.03E 64.95S Station 4: October 9 2012, located at 120.87E 65.13S Station 6: October 12 2012, located at 120.02E 65.25S Data are provided on grids with 50cm horizontal spatial resolution. For each station, the mean and variance of the sea ice draft, along with the number of observations in each grid cell, are provided. Data are provided in ESRI ASCII grid format and comma-separated (CSV) text files. CSV files do not include grid cells with no observations.
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This dataset contains in situ measurements of ice thickness, snow thickness, and freeboard along transects on the ice-station floes from the SIPEX2012. Ice cores were collected and snow pits were measured at the 0m, 50m and 100m mark along each transect, where possible. Ice temperature measurements are taken in the field as soon as the ice core sections have been recovered from the core hole. Additionally, ice cores were taken for density analysis at a few of the ice-core sites for independent verification of ice density. In addition, electromagnetic [EM] induction measurements of total ice and snow thickness were conducted along the transect where possible. Ice core were transferred -20oC freezer for thin-section analysis for sea-ice stratigraphy and crystallography. The cores are then cut up into suitable short sections, generally about 5cm long, to be melted for analysis of salinity and stable oxygen isotopes. The latter will occur after the end of this cruise. There is a data file for each ice station, containing a spreadsheet with the data. The spreadsheet contains information about how to interpret the data. Also included are the scanned field notes containing the hand-written (raw) data collected in the field. Among many, many volunteers, whose help is gratefully acknowledged here, the following persons were involved in data collection along the transect: Mr Olivier Lecomte, Univ Catholique, Louvain-la-Neuve, Belgium, Member of observation team, olivier.lecomte@uclouvain.be Dr T. Toyota, Inst Low Temp Science, Japan, Member of observation team, toyota@lowtem.hokudai.ac.jp Dr A. Giles, ACE CRC, Member of observation team, barry.giles@utas.edu.au Dr T. Tamura, NIPR, Japan, Member of EM observation team; tamura.takeshi@nipr.ac.jp Mr K. Nakata, EES, Japan, Member of EM observation team; kazuki-nakata@ees.hokudai.ac.jp Data were collected on the following dates: Ice Station 2: 27 - 28 September 2012 Ice Station 3: 03 - 04 October 2012 Ice Station 4: 06 - 08 October 2012 Ice Station 6: 13 - 14 October 2012 Ice Station 7: 19 - 23 October 2012 Ice Station 8: 29 October - 04 November 2012
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This dataset contains observations of ice conditions taken from the bridge of the RV Aurora Australis during SIPEX 2012, following the Scientific Committee on Antarctic Research/CliC Antarctic Sea Ice Processes and Climate [ASPeCt] protocols. See aspect.antarctica.gov.au Observations include total and partial concentration, ice type, thickness, floe size, topography, and snow cover in each of three primary ice categories; open water characteristics, and weather summary. The dataset is comprised of the scanned pages of a single logbook, which holds hourly observations taken by observers while the ship was moving through sea-ice zone. The following persons assisted in the collection of these data: Dr R. Massom, AAD, Member of observation team Mr A. Steer, AAD, Member of observation team Prof S. Warren, UW(Seattle), USA, Member of observation team Dr J. Hutchings, IARC, UAF, USA, Member of observation team Dr T. Toyota, Inst Low Temp Science, Japan, Member of observation team Dr T. Tamura, NIPR, Japan, Member of EM observation team Dr G. Dieckmann, AWI, Germany, Member of observation team Dr E. Maksym, WHOI, USA, Member of observation team Mr R. Stevens, IMAS, Trainee on observation team Dr J. Melbourne-Thomas, ACE CRC, Trainee on observation team Dr A. Giles, ACE CRC, Trainee on observation team Ms M. Zhia, IMAS, Trainee on observation team Ms J. Jansens, IMAS, Trainee on observation team Mr R. Humphries, Univ Wollengong, Trainee on observation team Mr C. Sampson, Univ Utah, USA, Trainee on observation team Mr Olivier Lecomte, Univ Catholique, Louvain-la-Neuve, Belgium, Trainee on observation team Mr D. Lubbers, Univ Utah, USA, Trainee on observation team Ms M. Zatko, UW(Seattle), USA, Trainee on observation team Ms C. Gionfriddo, Uni Melbourne, Trainee on observation team Mr K. Nakata, EES, Japan, Trainee on observation team
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These data describe pack ice characteristics in the Antarctic sea ice zone. These data are in the ASPeCt format. National program: United States Vessel: Nathaniel B. Palmer Dates in ice: 1 Sept 2007 - 31 Oct 2007 Observers: Penelope Wagner, John Pena, Sarah Anderson and others. Summary of voyage track: 06/09 3 GMT first record of ice edge at approx. 63 degrees 22 S, and 68 degrees 25 W toward Palmer Station, Antarctica in the Amundsen Sea due to electrical fire that began in Drake's Passage en route to the Bellingshausen Sea, Antarctica. 19 GMT arrived at NBP at Palmer Station, Antarctica at 64 degrees 46S and 64 degrees 04W to respond to safety protocol with NSF and Raytheon. 08/09 18:30 GMT depart Palmer Station toward Punta Arenas, Chile port. 09/09 22 GMT reach ice edge toward Chile. 24/09 17 GMT first record of ice edge at approx. 66 degrees 47S and 89 degrees 05W toward ice station Belgica in Bellingshausen Sea, Antarctica. 27/09 23GMT NBP parked at approximately 70 degrees 41S and 90 degrees 58W at Ice Station Belgica to perform 4 week station work. 24/10 10:30 GMT depart Ice Station Belgica toward Punta Arenas, Chile 27/10 8GMT reached ice edge. Total observations: 192 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 HH:MM:SS VISIBILITY CODE CLOUD IN OKTAS WEATHER CODE COMMENTS
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Imagery of Aurora Australis and sea ice captured by a 'quadcopter' (Inspire) drone launched from the ship
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Observation on V3 commenced as the Aurora Australis departed Fremantle and concluded on the approach to Hobart. The SOCEP research objective is to detect and document cetacean sightings and relevant environmental and other information throughout the voyage. The BROKE-West multidisciplinary voyage provides an opportunity to correlate sightings data with oceanographic and biology research conducted by other programs. Search effort is conducted over a broad range of weather conditions. The majority of Antarctic species are medium to large whales, with cues that can be detected in relatively high Beaufort sea states up to and including Beaufort Sea State 7. Observers search for whales while ever light, weather and sea conditions are suitable unless the vessel is stopped (e.g. CTD stations) or traveling slowly (e.g. trawling). Data are recorded using a laptop computer-based sighting program (Wincruz for Logger v3) that automatically logs under-way data from the ship's system including GPS position, ship course and speed, wind direction and speed, and also downloads time and date when required (F1 key). Data Collection In the preferred and highest level of (Full Effort) two observers are positioned on the port (Port) and starboard (Starboard) sides of the flying bridge (wheelhouse roof). The search area is an arc 180 degrees ahead to abeam of the vessel, primarily with the naked eye and augmented by the use of Fujinon 7x50 binoculars. A third observer (Tracker) is also stationed on the flying bridge. This person's role is to positively identify species, numbers and behaviour, particularly in the case of distant sightings, with the aid of Fujinon 25 x 150 binoculars (BigEyes). This team member also captures digital video footage of cetacean sightings when appropriate. The fourth rostered team member, the Central Logger (CL) is located on the bridge and communicates with those on the flying bridge via hand-held radio transceiver. The role of the CL is to record all relevant data on the Logger laptop computer. When in sea ice, a fifth member of the team ('Duplicate Identifier') is rostered to collect sea ice digital still images and video, and enter ice data in the SeaIce page in Logger. The CL monitors the effort activity and progressively updates as necessary general information such as search effort, observers, weather, sea conditions. Search effort is dropped a lower level of effort (CAS Effort), if visibility is determined to be too poor for Full Effort due to some combination of adverse weather conditions that precluded detection of most species (i.e. strong winds, fog, and large swell, confused swell, high sea state). If conditions become too poor to survey, or if the ship is traveling slowly or stopped, the effort is terminated (Off Effort). At such times the CL is generally rostered to remain on the bridge to ensure that passing whales do not go unreported, and to alert the rest of the team when the ship begins transiting at speed again or if visibility improves. Sightings When observers report whale sightings the CL enters the time, angle and distance from vessel, species identification, number of animals, sighting cue, behaviour and presence of ice and ancillary data. Cetaceans are identified to the lowest taxonomic level possible. Positive species identification is made only when there is certainty. Best, high and low estimates of group size are recorded for each sighting, and where more than one observer made an estimate, the final record is arrived at by consensus. Photographic records of cetaceans (and other wildlife and habitat) are collected opportunistically using digital cameras. Other Wildlife Seal and penguin species are logged while in sea ice, and opportunistically elsewhere. Flying birds within 100 metres of the ship are logged half-hourly, and large flocks are logged when observed. Other Event Occurrences such as the sighting or marine debris are logged as they are observed. Sea Ice Data Sea ice observations are recorded in Logger every 10 minutes while in transit in sea ice unless the ship is stopped or transiting slowly. Sea ice data are based on observations within a 1km 90 degree radius of the ship on the port side. A buoy of known diameter is suspended just above the waterline in front of the bridge to assist with estimates of ice and snow thickness. Sea ice still digital images are taken every 10 minutes while in transit in sea ice (unless transiting slowly), coinciding with SeaIce data recording in Logger. Sea Ice continuous video is taken for ten minutes each half-hour, showing the bow and horizon. The images and video assist in post cruise validation of sea ice thickness and assessment of the 1km radius for sea ice data collection. Sea ice habitat images are also captured when/where minke whales are sighted. Acronyms % Species 1 Percentage of group made up by Species 1 % Species 2 Percentage of group made up by Species 2 % Species 3 Percentage of group made up by Species 3 Bearing Bearing of sighting, in degrees, relative to the ship Beaufort Sea state assessment using Beaufort Scale (1-12) Berg Count No of icebergs 180 degrees ahead Best school size Best estimate of the number in group Casual observations (CAS) Lower level of Effort e.g. fewer observers Duplicate Identifier Person gathering/entering ice observations/images Dynamics Changes to the pod's composition. Effort Status Classification of level of observation effort End Time Time sighting observation ended Est distance Estimated distance from ship in nm. Floe Size Descriptive of size/nature of ice flows Full effort Highest level of observation effort Glare strength Classification of glare as it effects visibility Habitat Bathymetry Determined by reference to ship's chart High school size Highest estimate of the number in group Ice Conc Concentration of ice, in tenths Ice Thick Ice thickness in cm Ice Type Descriptive nature of ice Image File Identification number allocated to image taken at time of data entry In or Near Ice Ice conditions where wildlife was sighted Initial cue What first drew the observer's attention to the sighting. Left Glare Left extremity of glare Low school size Lowest estimate of the number in group Method Whether sighting was made using naked eye, 7x50 binoculars or 25x150 (Big-eye) binoculars Minke Vis Estimate of the distance at which a minke whale blow could be seen in prevailing conditions Notes For Recorder's additional information and comments Observer Person reporting the sighting Open Water Overall ice/water situation Port Observer monitoring the ocean on the port side Primary Ice Obs. Observations of thickest ice type Reaction The animal's reaction to the ship Recorder Person entering data into Logger Right Glare Right extremity of glare Secondary Ice Obs. Observations of second-thickest ice type Sightability Assessment of overall viewing conditions Sighting No Progressive numbering of whale sightings by Logger (default) Snow Thick Snow thickness in cm Snow Type Descriptive of snow on ice Species 1 When multiple species are being reported, with the species in greatest number listed first Starboard Observer monitoring the ocean on the starboard side Swell Code Descriptive of ocean swell Swell Direction Compass direction from which swell moving. Swim direction Animal's swim direction in degrees relative to the ship's heading Tertiary Ice Obs Observations of third-thickest ice type Topog Descriptive of ice topography e.g. ridging Total Ice Conc Ice concentration in tenths Tracker Observer using BigEyes binoculars to identify species, and assisting other observers generally Weather Code Weather conditions effecting visibility An excel spreadsheet containing a full list of terms used in the observation logs is available for download from the URL given below. This work was completed as part of ASAC projects 2253, 2655 and 2679 (ASAC_2253, ASAC_2655, ASAC_2679).