This dataset represents extents of Antarctic sea ice derived from passive microwave data. It includes: maximum and minimum sea ice extent based on 1989 - 99 data; maximum sea ice extent by month for the period October - March based on 1973 - 98 data; mean sea ice extent by month based on 1973 - 1998 data; and maximum sea ice extent averaged over the period 1987 - 1998. The data referenced by this metadata record has been sourced from another metadata record in this catalogue. For more information on the dataset see: Antarctic CRC and Australian Antarctic Division Climate Data Set - Northern extent of Antarctic sea ice [climate_sea_ice].

This dataset (provided as a series of CF-compatible netcdf file) consists of 432 consecutive maps of Antarctic landfast sea ice, derived from NASA MODIS imagery. There are 24 maps per year, spanning the 18 year period from March 2000 to Feb 2018. The data are provided in a polar stereographic projection with a latitude of true scale at 70 S (i.e., to maintain compatibility with the NSIDC polar stereographic projection).

This dataset contains scanned copies of documents related to historical work around icebergs and sea ice. All the files are in pdf format. The documents relate to work carried out between 1963 and 1986. The list of documents available in the download is as follows: Glaciology Sea Ice Log Mawson 1969 Glaciology Sea Ice Observations Wilkes 1963 Glaciology Ice Shear Apparatus Ice Deformation Tests 1972 Glaciology Iceberg Logs V1 and V5 1986

These data have been extracted from an Australian Antarctic Data Centre application, "Sea ice measurements database". The application has now been discontinued. The download file contains the extracted data, plus a sample data entry form. The extracted data are simply database tables that have been converted to csv format. Taken from the main page of the application: This archive contains in-situ measurements of Antarctic sea ice and snow cover properties, collected by many national programs over the past several decades. The data include physical, biological and biogeochemical measurements on ice cores and snow pit samples, as well as ice and snow thickness measurements from drilled transects across ice floes. The data are from all regions of the Antarctic pack ice in many different months of the year. Data can be submitted online using a standard proforma that can be downloaded from this site. The development of this site was a key recommendation from the International Workshop on Antarctic Sea Ice Thickness, held in Hobart, Australia in July 2006.

This map shows the distribution of the iceberg data extracted from ERS SAR images. Icebergs are identified in Synthetic Aperture Radar [SAR] images by image analysis using the texture and intensity of the microwave backscatter observations. The images are segmented using an edge detecting algorithm, and segments identified as iceberg or background, which may be sea ice, open water, or a mixture of both. Dimensions of the icebergs are derived by spatial analysis of the corresponding image segments. Location of the iceberg is derived from its position within the image and the navigation data that gives the location and orientation of the image. More than 20,000 individual observations have been extracted from SAR images acquired by the European Space Agency's ERS-1 and 2 satellites and the Canadian Space Agency's Radarsat satellite. Because images can overlap, some proportion of the observations represent multiple observations of the same set of icebergs. Most observations relate to the sector between longitudes 70E and 135E. The data set includes observations from several other discrete areas around the Antarctic coast. In general observations are within 200 km of the coast but in limited areas extend to about 500 km from the coast. This metadata record has been derived from work performed under the auspices of ASAC project 2187 (ASAC_2187). The map in the pdf file shows the extent of the coverage of individual SAR scenes used in the analysis and the abundance and size characteristics (by a limited colour palette) of the identified icebergs.

Described fully in (https://doi.org/10.21203/rs.3.rs-636839/v1 holder). Data The main CEL method, and a subsidiary Coastal Exposure Index or CEI (both described below), are based on daily sea-ice concentration products for the period 1979 through 2020. These products are derived from the multi-satellite passive-microwave brightness temperature time series using the NASA Team algorithm, mapped at 25 km x 25 km resolution and obtained from the NASA National Snow and Ice Data Center (NSIDC) Distributed Active Archive Center (DAAC). Both algorithms are designed to be adaptable for different resolution data. Complete coverage of the entire Antarctic coastal and sea-ice zones is obtained on a daily basis, except for 1979-July 1987 (once every two days). Missing single days during this period are interpolated from the adjoining day's sea-ice concentration values. Averages and climatologies are based on the period 1979-2020, unless otherwise stated. The continental land mask used (gsfc_25s.msk) is also obtained from NSIDC, and includes ice shelves (the seaward extremities of which are taken here to be coastline). Coastline grid points are defined from the continental land mask as any ocean grid point that has land/ice sheet adjacent to it. Analysis methods For this study, we developed two new but different algorithms for quantifying and monitoring Antarctic coastal exposure: the Coastal Exposure Index (CEI) and Coastal Exposure Length (CEL) method. The CEI technique is based on the detection of sea ice presence/absence radially out (northwards) from the coastline along each meridian (at one degree longitudinal spacing), following masking of the ice sheet. The CEI is simply defined as the number of longitudes with no sea ice (threshold set to less than 15% following convention) to the north of the continent, and hence runs from zero to 360. This methodology is trivial and code for this is not included. CEL is defined as the length (in kms) of the Antarctic coastal perimeter with no adjacent sea ice anywhere offshore (i.e. total exposure of the coast to the open Southern Ocean with no intervening sea ice), but excluding coastal polynyas. By this method, we use the land mask to determine if each coastal grid point has an immediately-adjacent ocean grid point that is ice-free (i.e. has a sea-ice concentration of less than 15%). If this criterion is met, then a nearest (adjoining) neighbour-testing technique is used to determine whether that ocean grid point is exposed in some way to the wider open ocean or is bound by neighbouring sea ice offshore. If any of the neighbouring grid points are classified as “exposed”, or if the total area of neighbouring ice-free grid points exceeds an arbitrary cut-off of 500,000 km2, then that coastal grid point is classified as “exposed”. Otherwise, the grid point and all sea-ice-free neighbouring grid points are deemed to be bounded by sea ice and are classified as a coastal polynya. The length of individual exposed coastal grid points is estimated by taking the square root of the respective pixel area. The length of coastal exposure, either regionally or net circum-Antarctic, is then simply the sum of the length of exposed coastal grid points. The IDL code used for calculating CEL is included here.

Ice shelf surface elevation data from an oversnow ground-based traverse along the centre of the Amery Ice Shelf from A509 (69.06 S, 72.15 E) to T4 (71.22 S, 69.48 E), including two transverse arms; between G1 (69.49 S, 71.72 E) and A119 (69.81 S, 73.28 E); and between T3 (70.79 S, 68.89 E) and T2 (71.00 S, 70.75 E) during the 1968 spring-summer season. More information can be found at the BEDMAP website. The fields in this dataset are: Mission ID Latitude Longitude Ice Thickness Surface Elevation Water Column Thickness Bed Elevation

This Atlas presents a compilation of AVHRR satellite images of sea ice adjacent to the coast of Eastern Antarctica. It is produced primarily for use by marine and vertebrate ecologists within the Australian Antarctic Division and as a contribution to the CCAMLR Ecosystem Monitoring Program. It is anticipated that this atlas will have value to a wider range of research and other uses including shipping operations. The Atlas provides one good image for each month between 1992 and 1999 for each of 5 regions of Eastern Antarctica centered on the following Antarctic Stations. Mawson station (M) - latitude 67 degrees 36.3 minutes S, longitude 62 degrees 52.2 minutes E Davis station (D) - latitude 68 degrees 34.6 minutes S, longitude 77 degrees 58.3 minutes E Casey station (C) - latitude 66 degrees 17.0 minutes S, longitude 110 degrees 31.2 minutes E Dumont D'Urville station (DD) - latitude 66 degrees 39.8 minutes S, longitude 140 degrees 00.1 minutes E Terra Nova Bay station (TN) - latitude 74 degrees 41.7 minutes S, longitude 164 degrees 07.0 minutes E Each image has been renavigated onto the same projection (Polar stereographic), gridded and a coastline added. Visible and thermal images are provided for the austral summer months, while only a thermal image is provided for the dark winter months. Due to either missing data or the lack of suitable imagery it has not been possible to provide a complete coverage over the period in all regions. Those 500 images presented were culled from some 20,000 images consulted. Images are presented with a schematic map indicating the major divisions of the image into open water, sea ice, cloud, land etc. Each month is accompanied by a short description of the sea ice conditions. The concept of a Sea Ice Atlas for scientific purposes was first proposed in 1999 and funded by the Australian Antarctic Division on the recommendation of the ANARE Mapping and Geographic Information Committee in 1999. Dr Kelvin Michael at IASOS was contracted to supervise the project and produce the Sea Ice Atlas in both hard copy and digital format. The AVHRR data are down loaded at the HRPT receiving facility Australian Antarctic Station of Casey. The HRPT archive is kept at the Antarctic Climate and Ecosystems CRC at the University of Tasmania.

A Lambert Glacier - Amery Ice Shelf series of airborne (Squirrel helicopter and Twin Otter fixed wing) RES and surface elevation profiles were conducted over two summer seasons; 1988/89 and 1989/90. Altogether nearly 10,000 km of various flight paths were undertaken, operating out of Mawson (67.60 S, 62.88 E), Davis (68.58 S, 77.97 E), Dovers (70.22 S, 65.87 E) or Beaver Lake (70.80 S, 68.18 E). More information can be found at the BEDMAP website. The fields in this dataset are: mission_id (unique mission identifier) latitude (decimal degrees) longitude (decimal degrees) ice_thickness (m) surface_elevation (m) water_column_thickness (m) bed_elevation (m)