This archive contains the data associated with the following study: Goosse, H., Dalaiden, Q., Francis, F., Mezzina, B. and Fogt R., The drop in Antarctic sea ice extent after 2016 similar to one at the end of the 1970s, In review for publication in Communication Earth & Environment. Regarding the atmospheric reconstructions (annual resolution), the variables included in the archive are: - sea-level pressure (slp) - sea ice concentration (sic) - sea surface temperature (sst) - 2-m air temperature (t2m) - regional sea ice extent for the main 5 antarctic regions (sie) The reconstructions performed with the 9 ESMs are provided. Each NetCDF file corresponds to one variable. For each variable, along with the reconstruction, an estimation of the uncertainty is provided. All fields are anomalies relative to the 1981–2010 period. The code to reproduce the reconstructions is available at https://github.com/dalaiden/DA_offline_PF. In addition to the atmospheric reconstructions, the sea-ice concentration field and regional sea-ice extent from the NEMO simulations forced with the atmospheric reconstruction based on CESM1-LM and CanESM2 are also included (anomalies relative to the 1981–2010 period). Please contact Quentin Dalaiden (quentin.dalaiden@uclouvain.be; quentin.dalaiden@gmail.com) or Hugues Goosse (hugues.goosse@uclouvain.be) if you wish additional variables or/and more information.