It has come to our attention that for charts from the beginning of the series in January 2003 through January 2006, the U.S. National Ice Center Arctic and Antarctic Sea Ice Charts in SIGRID-3 Format, Version 1 data set included an additional variable used to identify fast ice. Prior to February 2006 the U.S. National Ice Center (USNIC) used the form variable “CF”, filled with 0899, to identify some polygons as fast ice. We encourage users that are interested in fast ice to take this variable in to account (as well as FA, FB and FC) during this period. Further details on the use of “CF” have been added to the user guide.
Data set DOI: https://doi.org/10.7265/4b7s-rn93