Blending a sea-surface temperature (SST) dataset with land air temperature makes an implicit assumption that SST anomalies are a good surrogate for marine air temperature anomalies. It has been shown that this is the case, and that marine SST measurements provide more useful data and smaller sampling errors than marine air temperature measurements would. So blending SST anomalies with land air temperature anomalies is a sensible choice. This dataset contains monthly and seasonal blended sea-surface temperatures (MOHSST6) with land air temperature data from the Climatic Research Unit (CRU) at the University of East Anglia (P.D. Jones). Data are represented on 5 deg. grids from 1856 to May 2002. The data were provided by the Met Office.

MOHSST, (Met Office Historical Sea-Surface Temperature) is a gridded dataset of sea-surface temperature anomalies covering the period 1856-2006. MOHSST has now been superceeded by HadSST2. We now recommend use of HadSST2 instead of MOHSST for all purposes. MOHSST is only still available in case it is needed for direct comparison with earlier work where MOHSST was used. MOHSST is produced by taking in-situ measurements of SST from ships and buoys, rejecting measurements which which fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and averaging the resulting anomalies on a 5 by 5 degree monthly grid. Up to 1996 the measurements used are those in the U.K. Marine Data Bank; more recent years use data coming in through the GTS. After gridding the anomalies, bias corrections are applied to remove spurious trends caused by changes in SST measuring practices, and the data are smoothed to reduce noise. The data were provided by the Met Office Hadley Centre.