Climate Data

Sea Ice Concentration data from NOAA OI

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).

Key Strengths:

  • Gridded, long-term weekly or monthly data set convenient for modeling or analyses
  • Regularly updated

Key Limitations:

  • Higher resolution and more homogenous (single algorithm) data are available for the modern satellite period, 1979-present.
  • Similar to HadISST through ~1996; post 1996 no adjustments were made to account for changing satellite sources and/or algorithms employed by NCEP; switches made in 1997, 2004, 2006, 2009 and 2011 may strongly affect the timeseries

Years of Record

1981/10 to 2022/09
temporal metadataID:



Monthly | Weekly

Data Time Period Extended?

yes, data set is extended

Spatial Resolution

1° x 1°

Ocean or Land

Ocean Only

Missing Data Flag

missing data present

Vertical Levels

Input Data

adjusted passive microwave -derived sea ice from NASA Goddard and NCEP operations

Earth system components and main variables

Suggested Data Citation

from NOAA ESRL: NOAA_OI_SST_V2 data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA, from their Web site at

Data Access: Please Cite data sources, following the data providers' instructions.

Key Figures

Click the thumbnails to view larger sizes



Arctic sea ice: NOAA OI Average Arctic sea ice concentration for March 2003-2007 from the NOAA OI data set. (Figure by D. Schneider, NCAR).

Cite this page

National Center for Atmospheric Research Staff (Eds). Last modified 19 Sep 2022. "The Climate Data Guide: Sea Ice Concentration data from NOAA OI." Retrieved from

Acknowledgement of any material taken from this page is appreciated. On behalf of experts who have contributed data, advice, and/or figures, please cite their work as well.