HadISST consists of monthly mean fields of sea-surface temperature (SST, degrees C) and sea-ice concentration from 1870 through to two months before the current month. Missing values have been filled in a statistically optimal way. HadISST therefore has global coverage, and is available on a 1° latitude x 1° longitude grid.
Sea ice concentration fields from different sources were analysed to make them as consistent as possible through time. Care should be taken when using the sea-ice concentration data, particularly in the southern hemisphere where there is no realistic interannual variability in sea ice prior to 1973.
Latest month anomaly field
This map denotes anomalies in SST and fractional sea-ice concentration for the most recent available month relative to the 1961-90 climatology values. The El Niño Southern Oscillation originates in the equatorial Pacific off the coast of South America. If the SST anomalies in this region are warm then an El Niño event is currently underway.
Latest month absolute field
Absolute temperature fields from HadISST are used by the Met Office Hadley Centre and other climate modelling groups to provide lower boundary ocean conditions to atmosphere-only climate model runs. These have advantages over fully coupled models (that include a dynamical ocean component) for several (but not all) applications. This is because the timing and strength of many oceanic phenomena which affect the atmosphere, as well as the long-term response to human and natural influences on the climate system, are given by HadISST.
As well as the interpolated SST product HadISST, the Met Office Hadley Centre also provides a number of related surface and sub-surface ocean temperature datasets:
- HadSST2 – SSTs with no infilling of missing values
- MOHMAT – Night marine air temperatures from ships and buoys
- EN3 – Quality controlled sub-surface ocean temperatures
- HadDTR – Analysis of the diurnal temperature cycle in sea surface temperatures
Further information and data about HadISST are available
References
Rayner, N.A., D.E. Parker, E.B. Horton, C.K. Folland, L.V. Alexander, D.P. Rowell, E.C. Kent and A. Kaplan, 2003, Global analyses of SST, sea ice and night marine air temperature since the late nineteenth century, in press in J Geophys Res, 108, doi:10.1029/2002JD002670.