Summary
The weekly National Ice Center (NIC) ice chart dataset is compared with in situ sea-ice thickness observations from the AsPeCT program during five cruises for 1995 to 2000 time period in the Ross Sea to discern their quality for use in monitoring sea ice thickness and mass balance changes. Sea ice thickness calculations from both datasets are temporally joined with spatially averaged in situ observations matching their respective NIC ice chart using a Geographic Information System (GIS). The uncertainties of total ice thickness for both in situ observations and NIC ice charts are propagated through individual calculations and the GIS processing. Graphical tools, as well as quantitative measures, are used in this assessment. In general, the NIC ice chart thickness estimates correlate reasonably well with in situ observations. A temporal comparison of the NIC ice chart data along an individual ship track reveal insight into the differences, and these discrepancies are further investigated. Along with this evaluation of the ice chart dataset in the Ross Sea, the comparison is extended across the entire Southern Ocean.