With funding initially from the National Science Foundation (NSF) and several National Ice Center (NIC) grants, Dr. DeLiberty has been instrumental in converting paper ice charts to usable digital geographic databases for investigating sea ice thickness and volume in the Southern Ocean. Dr. Cathleen Geiger and a host of geography graduate students are collaborators in the creation of the final databases to include weekly ice concentration and thickness for the Southern Ocean for 1995-1998 when NIC operational products included the systematic reporting of ice type.
The initial focus began with the Ross Sea shown in the map below.
The map above displays the Ross Sea region showing the track of Nathaniel B. Palmer during May-June 1998 overlaid on a NIC ice chart for the week of 1 June 1998. The segment of ship track coincident with ice chart dates is emphasized along with an egg code displaying the ice properties of the sea-ice polygon labeled.
We examine the regional thickness features and the seasonal to interannual variability in the Ross Sea. The Figure below displays the annual cycle and interannual variability during this time period. As one example of an interesting feature is the tongue of thick ice from the Amundsen Sea near the coast throughout the annual cycle including its persistence through the summer months even as the Ross polynya grows to an extreme in summer (DJF) of 1996.
This research demonstrates the utility of the NIC operational ice charts for determining ice thickness and volume. The NIC Antarctic ice charts from 1995-1998 are an important resource for modelers examining thickness distribution and transport processes. Please see the DeLiberty et al. (2011) Deep Sea Research II paper for more details.