The US National Ice Centrer (NIC) produces a range of Daily Ice Analysis Products relating to the ice edge in both the Arctic and Antarctic, as well as the Marginal Ice Zone (MIZ). These products provide a daily edge position of the sea ice as lat/lon vertices, and have useful applications for those conducting ocean research in high latitudes.
Figure 1: Image illustrating the Antarctic Marginal Ice Zone.
The SOCCOM project provides one example of where MIZ data has useful applications. SOCCOM floats are an advanced type of argo float that measure CO2 and a range of other variables such as oxygen and nitrate levels, and pH. As the units are deployed in the Southern Ocean, sea ice can at times interfere with the floats ability to communicate data. Should the floats stop reporting, researchers need to know whether or not the floats could be under the ice, and NIC makes it much easier to gain accurate information about the floats situation. The MIZ product indicates the transition line between 0% and about 10% ice concentration, and between about 80% and 90% concentration. Of course, these concentrations only approximate, and human analysts make subjective judgements about the satellite imagery they are interpreting to create the daily edges.
In addition to daily products, on a weekly basis NIC produces analyses of ice concentration and stage of development. The Antarctic Daily and Weekly Products are both available online in image, text, shapefile, and KML format. KMZ files for both the Arctic and Antarctic are retained for two weeks here. The Ice Center also maintains a multi-year archive of these records, and of related products, with data available as charts and shape files. As well as being updated on a daily basis, the product is now being archived. In future, this daily data may be used to provide a monthly mean edge as lat/lon text file.