Sea Ice Concentration data from HadISST
Spanning 1871-present at monthly timesteps, HadISST provides the longest gridded sea ice data available for both the Arctic and Antarctic. It is a 1° x 1° spatially infilled data set that is It is intended as a consistent analyses for input into SST analyses or as boundary conditions for models. Version 1.1 is the currently available data set and is the one described here. HadISST combines data from historical ice charts from shipping, expeditions and other activities, passive microwave satellite retrievals (primarily the NASA Goddard NASA Team data set), and NCEP operational ice analyses (also based on NASA Team and NASA Team 2 algorithms). A major update of HadISST is planned and this page will be updated when pertinent information is available. The Climate Data Guide will have a separate page discussing the SST portion of HadISST.
Key Strengths
Combines many data sources into a long-term, continuous and spatially complete gridded sea ice data set
updated regularly
Key Limitations
The effect of the many data sources on the continuity of the timeseries is difficult to track and assess. Many obvious non-climatic breaks in the record exist, especially in the Southern Hemisphere
Shares weaknesses with source data, e.g. NASA Team, Chapman and Walsh NH sea ice, sparse SH pre-satellite observations
Higher resolution and more homogenous (single algorithm) data are available for the modern satellite period, 1979-present.
Met Office, Hadley Centre. HadISST 1.1 - Global sea-Ice coverage and SST (1870-Present), [Internet]. NCAS British Atmospheric Data Centre, 2006, Date of citation,. Available from http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_hadisst
NCAR RDA: "The data for this study are from the Research Data Archive (RDA) which is maintained by the Computational and Information Systems Laboratory (CISL) at the National Center for Atmospheric Research (NCAR). NCAR is sponsored by the National Science Foundation (NSF). The original data are available from the RDA (http://rda.ucar.edu) in dataset number ds277.3."
Rayner, N. A.; Parker, D. E.; Horton, E. B.; Folland, C. K.; Alexander, L. V.; Rowell, D. P.; Kent, E. C.; Kaplan, A. (2003) Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century, J. Geophys. Res., Vol. 108, No. D14, 4407 10.1029/2002JD002670
Cite this page
Acknowledgement of any material taken from or knowledge gained from this page is appreciated:
National Center for Atmospheric Research Staff (Eds). Last modified "The Climate Data Guide: Sea Ice Concentration data from HadISST.” Retrieved from https://climatedataguide.ucar.edu/climate-data/sea-ice-concentration-data-hadisst on 2025-07-10.
Citation of datasets is separate and should be done according to the data providers' instructions. If known to us, data citation instructions are given in the Data Access section, above.
Acknowledgement of the Climate Data Guide project is also appreciated:
Schneider, D. P., C. Deser, J. Fasullo, and K. E. Trenberth, 2013: Climate Data Guide Spurs Discovery and Understanding. Eos Trans. AGU, 94, 121–122, https://doi.org/10.1002/2013eo130001
Key Figures
Average Arctic sea ice concentration for March 2003-2007 from the HadISST data set. (Figure by D. Schneider, NCAR).
Annual Antarctic sea ice extent for 1871-2011 from the HadiSST 1.1 data set. 1871-1939 and 1947-1962 are covered by two climatologies. National Ice Center Charts were used for 1973-1978. Passive microwave satellite data begin in 1978. See Rayner et al (2003). Even during this period, there are discontinuities. In particular, SSMI degraded in early 2009 and NCEP switched to AMSR-E, resulting in spuriously high values for 2009-2011 (see Screen, 2011). (Figure by D. Schneider, NCAR).
Other Information
numerous sea ice charts, Walsh and Chapman sea ice (NH), adjusted passive microwave sea ice
1° x 1°