As of 9 June 2023, bi-weekly updating of Antarctic charts in the U.S. National Ice Center Arctic and Antarctic Sea Ice Charts in SIGRID-3 Format, Version 1 data set has been suspended indefinitely. The U.S. NIC has suspended production of the Antarctic charts and it is not known if or when production will resume. The Arctic charts will continue to be produced and made available on a bi-weekly basis.
Antarctic data prior to 9 June 2023 and documentation are still available from the data set web page at NSIDC: https://nsidc.org/data/G10013.
Data set DOI: https://doi.org/10.7265/4b7s-rn93