Data were collected during deployments of an instrumented Remotely Operated Vehicle on 5 sampling days to determine sea ice physical properties and measure transmitted under-ice radiance spectra (combined with surface irradiance measurements) to estimate the spatial distribution and temporal development of ice algal biomass in land-fast sea ice. The ROV was instrumented with a navigation/positioning system (linked to surface GPS), upward-looking sonar and accurate depth sensor (Valeport 500 (to determine sea-ice draft)), and a upward-looking TriOS Ramses radiance sensor as well as several video-cameras collecting under-ice footage. Parallel measurements included surface irradiance measurements. A readme file in the download explains the folder structure of the dataset.

Note - these data should be used with caution. The chief investigator for the dataset has indicated that a better quality dataset exists, but the AADC have been unable to attain it for archive. In addition to snow pits dug by other groups, several snow pits were dug at IMB/AWS deployment sites and at snow mast sites. Dates, locations, personnel, and purpose are listed in Table 1. Many of the data files include the raw weight measurements including the mass of the snow density shovel along with the snow. This needs to be corrected using the snow density shovel weight appropriate to each pit. Table 1 Snow Pits (comma separated) Date,Location,Personnel,Comments 2012-10-04,Floe 3 radiometer site,Katie,Full-depth snow density profile for evaluation of SMP data 2012-10-08,Floe 4 drift mast,Katie,Full-depth snow density profile for evaluation of SMP data 2012-10-14,Floe 6 buoy 1,Katie,Full-depth snow density profile for evaluation of SAMS WHOI-3 data 2012-10-14,Floe 6 buoy 2,Katie,Full-depth snow density profile for evaluation of SAMS WHOI-5 data 2012-10-20,Floe 7 drift mast,Ted,Snow pit to characterise snow at ice station 7 drift mast site 2012-10-23,Floe 7 drift mast,Katie,Full-depth snow density profile for evaluation of SMP data 2012-10-28,Helicopter buoy install,Petra,Snow pit for evaluation of SAMS- WHOI-4 buoy data 2012-10-29,Helicopter buoy install,Petra,Snow pit for evaluation of SAMS- TASI2-1 buoy data 2012-11-01,Floe 8,Ted,Snow pit for evaluation of WHOI-2 buoy data 2012-11-04,Floe 6 buoy re-install,Ted,Snow pit for evaluation of WHOI-6 buoy data

Ozone depletion over Antarctica increases UVB irradiances reaching the Earth's surface in the region. Marine microbes, that support the Antarctic food web and play an integral part in carbon cycling, are damaged by UVB. This research determines Antarctic UV climate, biological responses to UV from the molecular to community level, and combines these elements to predict UV-induced changes in Antarctic marine microbiology. A season of field work was undertaken over November and December 1994 based from Davis Station with the intention of making field measurements of ultraviolet radiation in the fast ice environment, as well as some of the lakes in the Vestfold Hills. Instrumentation The instrument for the measurements was a Macam spectral radiometer, owned by Geography and Environmental Studies, University of Tasmania. Field personnel were Dr Kelvin Michael (IASOS) and Mr Michael Wall (Honours student, Geography and Environmental Studies, UTas). The radiometer was equipped with a 25-metre quartz light pipe, with a cosine sensor attachment at the end. To make a measurement of ultraviolet irradiance, the sensor would be oriented so that its sensing surface was horizontal, and it would collect light which was then transmitted along the light pipe to the radiometer - a suitcase-sized unit which ran on battery power in the field. The radiometer was encased in a wooden box lined with polystyrene foam to provide protection from the elements and heat insulation. The radiometer was controlled via a laptop PC and the data were stored on the hard disk of the PC. Measurements Measurements of the attenuation of ultraviolet and visible radiation as a function of wavelength in water were made at the ice edge and lake measurement sites. At the ice edge, the light pipe was spooled over a wheel and lowered to preset depths (typically 1,2,4,8,16 and 32 m below the water surface). On a lake, a 25-cm augur hole was drilled, and the light pipe was lowered by hand to various depths, the exact depths chosen depended on the depth of the lake. Where the lake ice conditions permitted, a frame was lowered through the hole and used to lever the light pipe against the underside of the ice and a measurement of the ultraviolet and visible transmission of the sea ice was collected. In all cases, measurements of the ultraviolet and visible surface irradiance were collected before and/or after the sub-surface measurements. When the sky conditions were sufficiently clear, the direct and diffuse components of the ultraviolet and visible irradiance values were estimated, via the use of a shading apparatus. This would ensure that the radiometer would measure the diffuse component of the radiation field, allowing the direct component to be estimated by subtraction of the diffuse from the global (unshaded) measurement. On some occasions, the upwelling irradiance from the snow or ice surface was also measured, providing information on the spectral albedo of the surface. At each measurement, spectral irradiance values were generally collected for two spectral ranges: UV-B (280 - 400 nm, in 1-nm steps) and visible (400 - 700 nm, in 5-nm steps). In some cases, the wavelength boundaries were different - eg 280 - 350 nm for the UV-B, or 550 - 680 nm in the visible (corresponding to channel 1 of the NOAA AVHRR sensor). The data were stored by the PC as raw data files. The names of these files are automatically defined from the time on the logging PC as 'hhmmss.dti'. Note that the PC was operating on Australian Eastern Summer Time, 4 hours ahead of DLT. These data files were later read into Excel spreadsheets for manipulation. See the linked report for further information. The measurements are all in units of watts per metre squared per nanometre (Wm^-2 nm_-1) The heading UV-B refers to the fact that the data are collected in the ultraviolet part of the spectrum (280 - 400 nm) The heading AVHRR refers to the fact that the data are collected in the visible part of the spectrum (400 - 700 nm) The fields in this dataset are: UV Radiation Wavelength Depth AVHRR

As part of Australian Antarctic Science project # 4298 and Antarctica New Zealand project K131A, a total number of 24 sea ice sites were sampled for bio-optical measurements along 2 transects on land-fast sea ice in McMurdo Sound (Antarctica) during November 2014. Measurements included hyperspectral surface irradiance measurements (TriOS ASS) as well as under-ice radiance measurements using a TriOS ARC (350 – 900 nm, 3.3 nm resolution) radiometer mounted to an L-arm. After completion of radiometric measurements, snow thickness was measured with a ruler and an ice core was collected directly above the radiometer location. Sea-ice freeboard (tape measure) and ice thickness (ice core length) were recorded. Ice core (9 cm internal diameter) bottom sections (lowermost 0.1 m of ice cores) were collected and were used for determination of algal pigment content (using HPLC) and spectral ice algal absorption coefficients (ap, ad, aph). Sea ice physical properties including vertical profiles of ice temperature and salinity profiles were collected at some specific locations along the transects, which were sampled near Little Razorback Island and near Cape Evans, McMurdo Sound.

This dataset contains the Voyage Data from voyage 202122050 undertaken by the RSV Nuyina between February 12th and March 27th 2022. The principal objectives of the voyage were to retrieve equipment and exchange personnel from Davis Station, and resupply Macquarie Island Station. The EK80 acoustic instruments, underway oceanographic instruments in the OceanPack system, the ice and wave radar, and meteorological instruments were all run during this voyage. Whole of voyage data from the RSV Nuyina underway instruments. Includes uncontaminated seawater, meteorological, and wave radar data interpolated to 1 minute measurements. Wherever possible, each parameter and its associated unit of measurement complies with the NetCDF Climate and Forecast (CF) Metadata Convention Standard Name Table (Version 29) - “voyage_202122050\underway_merger\netcdf\202122050_1min_all.nc