We set out to achieve floe-scale 3-D mapping of sea ice draft and bio-optical parameters using a Multibeam SONAR and Hyperspectral radiometer mounted to an Autonomous Underwater Vehicle (AUV). The AUV utilised was the 'JAGUAR' Seabed-class vehicle from the Deep Submergence Laboratory at the WoodsHole Oceanographic Institution. The AUV comes with a CTD and ADCP. However these are not deployed as scientific sensors and therefore are unsupported in terms of metadata. In particular the CTD was not calibrated before or during the voyage. The AUV used a LongBaseLine system formed by three transponders to navigate to and from the survey grid. Two were located on the ice and the third was deployed from the back of the ship with an acoustic communications modem. Once at the survey grid beneath the sea ice, the AUV used the DVL to navigate using bottom-tracking of the underside of the sea ice. We conducted 4 missions beneath sea-ice during the SIPEX-II voyage. The current status of the data is that is in un-processed and unavailable until final processing is completed in 2013. Persons interested in the data should contact Dr Guy Williams directly for further information and preliminary figures relating to the AUV missions. The files currently in the archive are in raw form. Some preliminary data is provided for stations 2, 3, 4 and 6 as: floe-2-20120926.mat floe-3-20121003.mat floe-4-20121006.mat floe-6-20121013.mat These can be accessed using the Seabed_plot routines (MATLAB) in this folder. There is a readme file provided called what-is-this.txt Also included is the video footage taken from the AUV using a GoPro HD Hero. Video Codec: avc1 Resolution: 1920x1080 pixels Frame Rate: 29.970030 f/s Audio Codec: mp4a Audio Bitrate: 1536 kb/s Finally, plots of the data for ice stations 2,3,4 and 6 are included in the preliminary figures folder. The file names indicate which ice station the plots are from.

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.

More than 50 scientists from eight countries conducted the Sea Ice Physics and Ecosystem eXperiment 2012 (SIPEX-2). The 2012 voyage built on information and observations collected in 2007, by re-visiting the study area at about 100-120 degrees East. This was the culmination of years of preparation for the Australian Antarctic Division and, more specifically, the ACE CRC sea-ice group who lead this international, multi-disciplinary, sea ice voyage to East Antarctica. Work began at the sea-ice edge and penetrated the pack ice towards the coastal land-fast ice. The purpose of SIPEX-2 was to investigate relationships between the physical sea-ice environment, marine biogeochemistry and the structure of Southern Ocean ecosystems. While the scientists and crew did not set foot on Antarctic terra firma, a number of multi-day research stations were set up on suitable sea ice floes, and a range of novel and state-of-the-art instruments were used. These included: A Remotely Operated Vehicle (ROV) to observe and film (with an on-board video camera) krill, and to quantify the distribution and amount of sea ice algae associated with ice floes. An Autonomous Underwater Vehicle (AUV) to study the three-dimensional under-ice topography of ice floes. Helicopter-borne instruments to measure snow and ice thickness, floe size and sea ice type. Instruments included a scanning laser altimeter, infrared radiometer, microwave radiometer, camera and GPS. Sea ice accelerometer buoys to measure sea ice wave interaction and its effect on floe-size distribution. Customised pumping systems and light-traps to catch krill from below the ice and on the sea floor. Available at the provided URL in this record, is a link to a file containing the locations of all ice stations from this voyage.