Climatic Research Unit: Data Temperature The basic dataset (HadCRUT) is a combination of land air temperature anomalies (Jones, 1994, CRUTEM1) and sea surface temperature anomalies (Parker et al., 1995) on a 5 x 5 grid-box basis. The merging of the two datasets is discussed in Parker et al., 1994 and more recently in Jones et al., 2001. Both components of the dataset are expressed as anomalies ...