Met Office Hadley Centre observations datasets
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Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST.2)

Only sea ice concentrations are available at present.
The SSTs for this data set are not currently available on this website.

The Met Office Hadley Centre's sea ice and sea surface temperature (SST) data set, HadISST, is a unique combination of monthly globally-complete fields of SST and sea ice concentration on a 1 degree latitude-longitude grid from 1850 to date. The latest versions replace the previous version (HadISST1), and the Global sea Ice and Sea Surface Temperature (GISST) data sets.

The field for the month-before-last (see image below) is added to the data set in the first half of every new month.

Brief description of the data

For a detailed description of HadISST. sea ice concentrations and the production process, see the cited paper (in the References box). We recommended you read this before using the data. The lastest version, HadISST., contains a number of small improvements/bug fixes compared to HadISST. See HadISST versions for more details.

It is worth noting that HadISST.2 data contains monthly mean concentrations, wheras HadISST1 contains monthly medians. It also has a different land/sea (missing data) mask (HadISST.2 contains more ocean/ice grid boxes than HadISST1). See the Data Download page for more information.

Passive microwave data have been combined with historical sources, such as sea ice charts, to create global analyses on a 1 degree grid from 1850 to present. Climatology was often used when no information about the sea ice was available. Bias adjustments were calculated using periods of overlaps between the different data sources used (when possible), and then applied to the concentrations. National Ice Centre charts from 1995 to 2007 were used as a reference to achieve this. A method was developed for estimating the concentrations within the ice pack using the distance from the ice edge. This was used when only the extents were known or when the original concentration fields were heterogeneous.

Overall, HadISST. contains more ice than HadISST1, with higher concentrations, shorter marginal ice zones, and larger extents and areas in some regions and periods.

Other information

Various figures are produced from the monthly gridded fields.

An animation of the September Arctic sea ice concentration fields for 1979 to present can be found here.

Map of sea ice concentration for the latest available month

Go to download page Data are available from the download page without charge for the purposes of private study and scientific research, but please read the terms and conditions.

Commercial and media enquiries

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When using the sea ice data in a paper, the following is the correct citation to use:

Titchner, H. A., and N. A. Rayner (2014), The Met Office Hadley Centre sea ice and sea surface temperature data set, version 2: 1. Sea ice concentrations, J. Geophys. Res. Atmos., 119, 2864-2889, doi: 10.1002/2013JD020316.

Please always state the full version number that has been used (e.g. HadISST. ), cite the journal paper and this website, and give the date of download.