Observations of the sea ice near Mawson were carried out in 1980, concentrating on the thickness of the ice at several points, and the accumulation and ablation of snow/ice cover on the ice. The ablation measurements were carried out by laying 23 ablation stakes out in two fields - a set of eight stakes in a straight line, and a set of 15 in a triangle. Results from both sets of observations were recorded in a log book, currently archived at the Australian Antarctic Division.

Water density and salinity readings from Davis during the under-ice diving program in 1982. The written logs are archived at the Australian Antarctic Division.

Metadata record for data from ASAC Project 2504 See the link below for public details on this project. In this project a sea-ice model for application in Southern Ocean climate and forecasting studies will be developed to amend identified deficiencies in numerical models (i.e. unaccounted short-term dynamics; or non-suitable ice rheology). In-situ deformation and ice-stress data will be used to derive parameterisations suitable for the Southern Ocean pack. Antarctic sea ice is an important component of the Southern Hemisphere climate. It provides a habitat for algae, plankton and for larger species such as mammals or penguins. It is a transport medium for freshwater and biological matter. On the other hand it acts like a barrier between ocean and atmosphere in regard to the exchange of thermal energy, water vapour and gases. Sea ice affects the polar climate in many ways: E.g., by effectively insulating the ocean from the colder atmosphere the sea ice enables an advection of relatively warm water onto the shallow Antarctic continental shelf. This warmer water is then available to interact with other components of the climate system, such as by basal melting of the continental ice shelves [Jenkins and Holland, 2002]. Also, due to its high albedo, the sea ice has a large-scale effect on the net incoming solar radiation [Ebert et al., 1995] and reduces the absorption of solar energy into the upper ocean. The thermodynamic growth of seaice and the consequent desalination of the ice gives rise to a transport of salt from the ice into the ocean, which increases the water density over the shelf, thereby driving the deep vertical overturning cell in the global ocean circulation. High ice-growth rates (e.g., in regions of polynyas) are generally concentrated in small areas in shallow waters. These regions are often insufficiently resolved or even unresolved in coupled climate models, which are generally configured to run at a spatial resolution of 2 degree longitude by 1 degree latitude or coarser [Zhang and Hunke, 2001]. The specific objectives of this project are to: * identify the variabilities in the sea-ice characteristics and the underlying physical processes; * identify the time scales, at which the sea ice interacts with the ocean and atmosphere; * assess the contribution of sub-daily ice motion and deformation due to tidal forcing and inertial response to changes within the Antarctic ocean-ice-atmosphere system; * derive the impact of sub-daily ice dynamics on the sea-ice area, extent and mass on interannual and decadal time scales; * determine the scale effect of dynamic processes on the accuracy of modelled sea-ice parameters using a global high-resolution model; * identify model uncertainties through comprehensive validation studies. However, logistical problems prevented the project from collecting any data in the field. To overcome the paucity of planned buoy data we used the following data sets to address some of the aspects of the original proposal: 1) Sea-ice buoy data: ISPOL 2004: See AAS #2500 for metadata. 2) Numerical investigations: We have investigated the failure of sea ice using an isotropic model [Hibler, 1979], where ice strength is modelled as a random variable in the model space. In situ weakening was prescribed by a fracture-based Coulombic rheology [Hibler and Schulson, 2000]. We realised this by parameterising weakening with an ice-strength parameter of 1000 and initialising the ice strength across the model grid by random. The simulations were run over a 2000 km by 2000 km region and forced, from rest, with an idealised wind field. We analysed the sensitivity of failure to ice strength and wind stress as well as the intersection angle of the wind stress, and conducted idealised 2D failure experiments.

The Holocene sea-ice project brings together for the first time, records from the Antarctic continent and deep sea sediments that will allow us to calibrate three sea-ice extent surrogates, validate their use in contrast to satellite observations and explore climatic influence on the physio-ecological environment over the last 10,000 years. Spreadsheet 1 (appendix A): Complete list of Accelerator Mass Spectrometry (AMS) dating completed on E27-23 from various identified sources with original 14CAge and reported error. Three dates identified as Burckle pers comm. here were provided by Dr Lloyd Burckle (LDEO) to Dr L. Armand for this work. Outlier attributions are identified; the term Averaged identifies the two samples where final calibrated dates were averaged in this work. All remaining AMS dates were converted to calendar ages using the linear-based CALIB07 (Stuiver and Reimer, 1993) with calibration to the Marine13 dataset (Reimer et al., 2013) at 95% confidence (sigma 2) and included a correction for the surface water reservoir age of ~752 years at the site of core E27-23 resolved from the marine radiocarbon reservoir correction database and software available from http://radiocarbon.LDEO.columbia.edu/ (Butzin et al., 2005). The percent Marine Carbon relative attribution is provided. The Median age (Cal Yr BP) used as the final age at each respective (mid) depth is provided. In Appendix A the dates are all ages in years, however some are uncalibrated ages and others are Cal yr BP (= calendar years before present). So in terms of headings in Table A: Raw 14C age yr BP - is the raw age provided by radiocarbon dating without any corrections applied. It is in years before present. Corrected raw age (RA=752) - is the raw age with a local RA (Reservoir Age) correction applied and is still in years before present. The remaining ages are calendar years before present having been calibrated. All formats follow recommendations for reporting raw 14C dates and their calibration ages. Spreadsheet 2 (appendix B): Comparison of calibration output from the input of accepted 14C dates using OXCAL 4.2 (Bronk Ramsey 2009; Blaauw 2010), and CALIB07 (Stuiver and Reimer, 1993), both using the Marine13 calibration curve (Reimer et al., 2013) at 95.4% confidence (sigma 2) and including a correction for the surface water reservoir age of ~752 years at the site of core E27-23. The calibration output difference between the median Cal Yr BP, regardless of calibration method employed, was greater than or equal to 40 Cal Yr BP. Calibration data from the output of CALIB07 has been used in this paper to determine chronostratigraphy. Spreadsheet 3 (appendix C): The foraminiferal stable isotope data from E27-23. Ratios of oxygen (delta 18O) measured from the planktonic foraminifer Neogloboquadrina pachyderma sinistral (greater than 150 microns). Isotope values are reported as per mil (%) deviations relative to the Vienna Peedee Belemnite (VPDB). Spreadsheet 4 (appendix D): The paleo winter sea-ice concentration (wSIC) estimates for marine sediment core SO136-111. The calendar ages, in thousands of years before present (kyr BP), are provided for each sample from core SO136-111. For each of the samples in core SO136-111, we have provided the estimates winter sea-ice concentration (%), along with the associated lower and upper bounds for the 95% confidence interval around the estimated winter sea-ice concentration (%), for both GAM/WSI/13 and GAM/WSI/ETS. The final two columns provide the estimated average annual monthly sea-ice cover for each sample within core SO136-111, originally estimated using the Modern Analogue Technique, by Crosta et al. (2004). Finally, we provide the estimated summer sea surface temperature, again using the Modern Analogue Technique, from Crosta et al. 2004. Spreadsheet 5 (appendix E): The paleo wSIC estimates for marine sediment core E27-23. The calendar ages, in thousands of years before present are provided for each sample from core E27-23. For each of the samples in core E27-23, we have provided the estimated winter sea-ice concentration (%), along with the associated lower and upper bounds for the 95% confidence interval around the estimates for winter sea-ice concentration (%).

This file contains a log of biological observations undertaken at Mawson station between 1977 and 1978. The observed animals include: Weddell Seals, Skuas, Snow Petrels, Wilson's Storm Petrels, Pintado Petrels, Giant Petrels, Crabeater Seals, Elephant Seals, Leopard Seals and Adelie Penguins. The log also includes a number of sea ice observations made at Mawson Station. The hard copy of the log has been archived by the Australian Antarctic Division library.

This file contains a log of biological observations undertaken at Mawson station between 1971 and 1974. The observed animals include: Wilson's Storm Petrels, Petrels, Giant Petrels, Skuas, Emperor Penguins, Snow Petrels, Silver Grey Petrels, Antarctic Petrel, Weddell Seals, Crabeater Seals, Leopard Seals, Elephant Seals, Ross Seals and Whales. The log also includes a number of sea ice observations made at Mawson Station. The hard copy of the log has been archived by the Australian Antarctic Division library.