The NOAA Optimal Interpolation (OI) v2 sea ice data set contains gridded, weekly or monthly resolution sea ice concentration estimates for both the Northern and Southern Hemispheres. It is intended as a consistent analyses for input into SST analyses (and is the basis for calculating SSTs in sea ice zones for the OI SST data) or as boundary conditions for atmospheric models. The sea ice portion of NOAA OI v2 is produced similarly to HadISST sea ice, using adjusted passive microwave derived sea ice data from from the NASA Goddard NASA Team algorithm followed by operational sea ice data from NCEP. Users should be aware that the NOAA OI sea ice contains similar discontinuities as HadISST in recent years (see Screen, 2011).
from NOAA ESRL: NOAA_OI_SST_V2 data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at http://www.esrl.noaa.gov/psd/
National Center for Atmospheric Research Staff (Eds). Last modified 06 Jan 2017. "The Climate Data Guide: Sea Ice Concentration data from NOAA OI." Retrieved from https://climatedataguide.ucar.edu/climate-data/sea-ice-concentration-data-noaa-oi.