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  • 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

  • This dataset is daily passive microwave-derived Advanced Microwave Scanning Radiometer 2 (AMSR2) Antarctic sea ice motion dataset, which is the version of rectified two problems exist in Kimura et al. (2013) sea ice motion product, with ascending (ASC), descending (DES) and combined datasets, which format is DAT file. It is produced at 60×60 km resolution on a regular 127×134 grid covering the entire Southern Ocean (40°~ 90° S, -180°~180° E), for the period of 2017-05-20 to 2017-11-26 (186 days) and 2018-04-08 to 2018-08-20 (135 days). These were calculated by applying the MCC method to 36 GHz, 10 km resolution AMSR2 Level-3 36 GHz TB images (both vertical and horizontal polarization) from the Japan Aerospace Exploration Agency (JAXA). Included datasets: latitude - description: latitude of each gridded pixel - dimensions: 2 - size: [127, 134] longitude - description: longitude of each gridded pixel - dimensions: 2 - size: [127, 134] u_weddell - description: daily ASC, DES and combined u component of sea ice velocity on each pixel, from 2018-04-08 to 2018-08-20 covered entire central Weddell Sea buoy trajectory time-span, 135 days in total. - dimensions: 4 - size: [127, 134, 135, 3] ([x coordinate, y coordinate, days, ASC/DES/combined]) v_weddell - description: daily ASC, DES and combined v component of sea ice velocity on each pixel, from 2018-04-08 to 2018-08-20 covered entire central Weddell Sea buoy trajectory time-span, 135 days in total. - dimensions: 4 - size: [127, 134, 135, 3] ([x coordinate, y coordinate, days, ASC/DES/combined]) u_ross - description: daily ASC, DES and combined u component of sea ice velocity on each pixel, from 2017-05-20 to 2017-11-26 covered entire Ross Sea buoy trajectory time-span, 186 days in total. - dimensions: 4 - size: [127, 134, 186, 3] ([x coordinate, y coordinate, days, ASC/DES/combined]) v_ross - description: daily ASC, DES and combined v component of sea ice velocity on each pixel, from 2017-05-20 to 2017-11-26 covered entire Ross Sea buoy trajectory time-span, 186 days in total. - dimensions: 4 - size: [127, 134, 186, 3] ([x coordinate, y coordinate, days, ASC/DES/combined]) Study domain: 40°~ 90° S, -180°~180° E Time-scale: 24 h (for ASC and DES datasets) and 39 h (for combined dataset). Time period: from 2017-05-20 to 2017-11-26 (186 days) and from 2018-04-08 to 2018-08-20 (135 days). Variables and geographic projection detail are saved in the dataset as Readme.txt

  • This dataset contains ice motion observations made under the Australian Antarctic Program, projects 4593 and 4506. Data was obtained using two open-source ice motion loggers, hereafter ice buoys. Two ice buoys were deployed on landfast ice just north of the Swain Group, Antarctica (66.2 degr. S, 110.6 degr. E), on 13 October 2020. Instruments were retrieved on 10 November 2020. The ice buoys measure motion in 9-degrees-of-freedom at 10Hz using a VectorNAV VN-100 IMU, with an accuracy of O(mm) for short waves and O(cm) for long waves. Both instruments also record their geographical location through GPS. Full time series of their motion is processed on board and summaries are send through Iridium. Wave spectra and GPS coordinates were transmitted roughly every 4 hours. The dataset comprises the raw data measured by the two ice buoys, we have referred to them as AAD_17 and AAD_18 for administrative reasons. Data output for each buoy is: A = vertical acceleration (mean subtracted) (m/s^2); P = pitch (degrees); R = roll motion (degrees); z = surface elevation (m); t = UTC time (Matlab ‘datenum’ format, i.e., days since year 0000); lat = latitude; lon = longitude. The geographical coordinates ‘lat’ and ‘lon’ are in degrees.

  • This dataset contains numerical simulation results of the wave fields in the Davis Sea from end of December 2019 to start of February 2020. Hindcasts were obtained through the third-generation spectral wave model WAVEWATCH-III (hereafter WW3). A high resolution Davis Sea regional grid (resolution 0.1 degree, 60-80E longitude, 70-60S latitude) was nested into global grid domain (resolution 0.5 degree, 80S-80N latitude). The global model is forced with 0.5 degree sea ice concentration and 10m-wind fields from ECMWF's ERA5 reanalysis. The Davis sea model is forced with 0.1 degree 10m-wind fields from ECMWF's archived forecasts, and high-resolution (3.125km) AMSR2 satellite data for sea ice concentration (Beitsch et al., 2013 updated). Ice-induced wave attenuation is parameterized following Sutherland et al. (2019, doi:10.1016/j.apor.2019.03.023) whilst the break-up of sea ice is parameterized as 'broken' or 'unbroken' based on the break-up parameter of Voermans et al.(2020, doi:10.5194/tc-14-4265-2020). The numerical simulations have been calibrated using the buoy-observations of Voermans (2022, dataset, doi:10.26179/cdmx-n995). Sensitivity of the simulations to sea ice properties was tested and all results are provided in the dataset. The data tree: * global: model outputs for the global domain - ncfield: gridded wave and ice data for this domain in netCDF-4 format - nests: binary data used by WW3 for boundary conditions for the Davis Sea grid - restarts: binary data used by WW3 for restarting this domain * davis_sea: model outputs for the Davis Sea domain - ncfield: gridded wave and ice data for this domain in netCDF-4 format - ncpoint: spectral wave data for a few points in the Davis Sea in netCDF-4 format - nctrack: spectral wave data following the wave buoys of Voermans et al (2022) in the Davis Sea in netCDF-4 format - restarts: binary data used by WW3 for restarting this domain - IHOT: binary text field of broken and unbroken ice for restarting this domain File naming convention (by example): ww3.20200101_20200103_M3D_IHOT_H0P0325_A0P01_YY9P0_SS0P1_HH0P55.nc * 20200101_20200103 identifies the datespan of the simulation in YYYYMMDD format * A0P01 refers to the attenuation coefficient of the model (where P stands for 'point'), in this case, A=0.01 * YY is the Young's Modulus timed 10^9, here, Y-9.0e9 Pa * SS is the ice strength 'sigma' times 10^6, here sigma=0.1e6 * HH is the ice thickness, here h=0.55 m * H0P0325 is proportional to the epsilon calibration coefficient (H=0.5*ice_thickness*epsilon). * M3D refers to the 3rd instantiation of the model * IHOT refers to hot start using the ice breakup field from the previous week. ww3.*_M3D_IHOT_H0P065_A0P05_YY6P0_SS0P55.nc is considered the baseline file (note, this simulation only covers the first two weeks of the study period). Reference: Beitsch, A., Kaleschke, L. and Kern, S. (2013). "AMSR2 ASI 3.125 km Sea Ice Concentration Data, V0.1", Institute of Oceanography, University of Hamburg, Germany, digital media

  • This dataset contains ice motion observations made under the Australian Antarctic Program, Projects 4593 and 4506. Data was obtained using two Spotter wave buoys (Sofar Ocean Technologies), hereafter wave buoys, and two open-source ice motion loggers, hereafter ice buoys. Instruments were deployed on (land)fast ice on the eastern rim of the Amery Ice Shelf, Antarctica (69.2 degr. S, 76.3 degr. E), on 7 December 2019. After the break-up of the ice occurring at the start of January 2020, instrumentation started to drift with the ice. Last transmission recorded was on 10 March 2020. The wave buoys measure their 3-axis motion at 2.5 Hz through GPS and have an accuracy of approximately 2 cm for the recorded significant wave height. The ice buoys measure motion in 9-degrees-of-freedom at 10Hz using a VectorNAV VN-100 IMU, with an accuracy of O(mm) for short waves and O(cm) for long waves. Both instruments also record their geographical location through GPS. Full time series of their motion is processed on board and summaries are send through Iridium. For the ice buoy wave spectra were transmitted roughly every 3 hours. The transmission interval for the wave boys was variable, ranging from every half an hour to every 3 hours. Data transmitted by the wave buoys was either integral wave properties or the complete wave spectrum. In the dataset, WB and IB are abbreviations for wave buoy and ice buoy, respectively. This dataset includes all observations transmitted during the measurement campaign (WB1, WB2, IB1, IB2). E = wave energy spectrum (m2/s); f = wave frequency (Hz); a1, a2, b1, b2 = Fourier coefficients; Hs = significant wave height (m); Tp = peak period (s); Tm01 = mean period (s); Dir_peak/mean = peak and mean wave direction and 'spr' refers to spreading; volt = battery voltage (V). Time is in UTC, and in Matlab’s datenum format (i.e. the number of days since year 0000). The geographical coordinates ‘lat’ and ‘lon’ (latitude and longitude, respectively) are in degrees. Note, as the ice buoys transmit the GPS coordinates and wave data in separate data messages, for the ice buoys ‘time’ refers to the reference time of the wave properties Hs and Tp, whereas ‘GPStime’ refers to the reference time of the geographical coordinates (lat and lon). For the wave buoy, all data is transmitted at the same time.

  • In situ Lagrangian drifter positions were collected from nine expendable sea-ice buoys. Positions were collected by GPS receivers aboard each buoy and relayed via the CLS Argos satellite data system. The scientific proposal for this project was based on the deployment of two meso-scale buoy arrays over the continental shelf break in the SIPEX 2012 experimental region. Resolving of ice motion over the continental shelf and the shelf break is expected to provide crucial information on sea-ice deformation and ice strength. However, due to the unfavourable cruise track and also due to operational issues with helicopter support, it was not possible to deploy any of the meso-scale buoy arrays. Instead buoys were deployed to resolve ice deformation within the wider SIPEX 2012 region. Position data are available hourly from most buoys. CLS Argos transmitted data suffer from a data transmission blackspot just prior to local none, when there will be no data available. Data processing will be carried out as described in Heil et al. [2008] The dataset is build from ASCII files for each buoy with time stamps and observed latitude and longitude. The format (by column [C] for each file is as following: C1: Program ID C2: Buoy ID C3: Year C4: Month C5: Day C6: Hour C7: Minute C8: Second C9: Day-of-year C10: Lat (degN) C11: Lon (degE)

  • Envisat was was launched on 01/03/2002, by ESA and operated until 08/04/2012. It provided suitable imagery for the austral winters (May - November) of 2007 to 2011. Envisat caried a C-band (5.33 GHz; wavelength ∼ 5.6 cm) Advanced Synthetic Aperture Radar [ASAR], capable to acquire data in multiple modes (image, alternating polarization, wave, ScanSAR (wide swath), and ScanSAR (global monitoring)) at various incidence angles and in several polarisations. Of ASAR's five distinct measurement modes, the following two modes may be used to derive sea-ice motion from overlapping images in our project: 1. ASAR Wide Swath Mode -- 400 km by 400 km wide swath image. Spatial resolution of approximately 150 m by 150 m for nominal product. VV or HH polarization. 2. ASAR Global Monitoring Mode -- Spatial resolution of approximately 1000 m in azimuth by 1000 m in range for nominal product. Up to a full orbit of coverage. HH or VV polarization. For further detail, see ESA's Copernicus web portal. Sea-ice motion is derived from suitable SAR image pairs with sufficient spatial overlap but relatively short time separation, i.e. ideally 6days or less. Image-crosscorrelation analysis is employed to identify displacement vectors within the image pair. The underlying processing and analysis is part of the (mostly) automated IMCORR [IMageCORRelation] Processing, Analysis and Display System [IPADS]. This study uses C-band (HH polarisation) ASAR scenes, with an image pixel size of 75 m across a 405 km swath. -- For further information see Giles et al., Semi-automated feature-tracking of East Antarctic sea ice from Envisat ASAR imagery, Remote Sensing of Environment, 115, 2267-2276, 2011. Acknowledgement: All Envisat ASAR data are courtesy of the European Space Agency, and were obtained under agreement with ESA. The International Space Science Institute (ISSI), Bern, Switzerland, is acknowledged for supporting this study via Projects 137 and 169.

  • 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 [https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019JC015418; pre-print https://arxiv.org/pdf/1906.10839.pdf]. 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)

  • Sea-ice motion derived from two (partially) overlapping ESA Sentinel1 [S1]A or B scenes. Satellites S1A/B carry C-band (5.405 GHz) Synthetic Aperture Radar [SAR] sensors. For this data set images from the Extra Wide swath (EW) mode of operation (swath width 410 km) have been used. EW mode data are available as a medium-resolution ground range detected (GRD) product, i.e., resolution of 93 × 87 m and pixel size 40 × 40 m. Approximately two-thirds of the EW mode data recorded over the Antarctic area are dual-polarisation (HH + HV) products. The remainder are mainly single-polarisation (HH) products. For further detail, see ESA's Copernicus web portal. Ice motion is derived from suitable SAR image pairs with sufficient spatial overlap but relatively short time separation, i.e. ideally 6 days or less. Image-crosscorrelation analysis is employed to identify displacement vectors within the image pair.

  • This dataset contains ice motion observations made under the Australian Antarctic Program, Projects 4593 and 4506. Measurements of ice motion where made on (land)fast ice on the eastern rim of the Amery Ice Shelf, Antarctica (69.2 degr. S, 76.3 degr. E) and on landfast ice in Gronfjorden, Svalbard (78.0 degr. N, 14.2 degr. E). Data was obtained using Spotter wave buoys (Sofar Ocean Technologies), hereafter wave buoys, and open-source ice motion loggers, hereafter ice buoys. Instrumentation was deployed on top of the sea ice with the main motivation to measure its vertical motion due to ocean waves. The wave buoys 3-axis measure motion at 2.5 Hz through GPS and have an accuracy of approximately 2 cm for the significant wave height. The ice buoys measure motion in 9-degrees-of-freedom at 10Hz using a VectorNAV VN-100 IMU, accuracy is O(mm) for short waves and O(cm) for long waves. Both instruments also record their geographical location through GPS. Full time series of their motion is processed on board and summaries are send through Iridium. For the wave buoy, this occurred at an interval of 30 minutes. For the ice buoy this occurred every 3 hours. In the dataset, WB and IB are abbreviations for wave buoy and ice buoy, respectively. This dataset covers 2-8 January 2020 for the Antarctic campaign (WB1, WB2, IB1, IB2) and 14-28 March for the Arctic campaign (IB3, IB4, IB5) and includes significant wave height, peak period and the geographical coordinates of the instrumentation. ‘Hs’ refers to significant wave height (in meters). ‘Tp’ refers to peak period (in seconds). Time is in UTC, and in Matlab’s datenum format (i.e. the number of days since year 0000). The geographical coordinates ‘lat’ and ‘lon’ (latitude and longitude, respectively) are in degrees. Note, as the ice buoys transmit the GPS coordinates and wave data in separate data messages, for the ice buoys ‘time’ refers to the reference time of the wave properties Hs and Tp, whereas ‘time_latlon’ refers to the reference time of the geographical coordinates. For the wave buoy, all data is transmitted in one message.