This data set is only available for a restricted user group, please contact us if you want to access these data.
Coverage, spatial and temporal resolution
Period and temporal resolution:
Coverage and spatial resolution:
- Spatial resolution: 5° x 5°, cartesian grid
- Geographic longitude: -177.5°E to 177.5°E
- Geographic latitude: -87.5°N to 87.5°N
- Dimension: 72 columns x 36 rows
- Altitude: 2 m (CRUTEM), 0 m & 2 m (HadCRUT)
Estimates are made of the uncertainties arising from thermometer accuracy, homogenisation, sampling grid boxes with a finite number of measurements available, large-scale biases such as urbanisation and estimation of regional averages with non-complete global measurement coverage.
Because the number of observations forming each grid-box average in CRUTEM3 or CRUTEM4 is not constant in space or time, the variability in the gridded anomalies also changes: grid-box averages made from many observations have a smaller variance than those made from few. We have made a "variance adjusted" version of the dataset, where the anomalies have been statistically processed to homogenise the variances. These datasets are denote with an appended "v", i.e. CRUTEM3v and CRUTEM4v or HadCRUT3v. These data sets do not come with additional uncertainty estimates (of course).
For HadCRUT4 no variance adjusted version of the data set is available because the processing changed. Instead, the temperature anomaly given in the main data set is the median of 100 ensembles of the temperature anomaly distribution. We only offer this median value here; however all 100 ensembles as well as the error covariance matrices are available on request.
For more information we refer to the references.
CRUTEM3 & HadCRUT3:
E-Mail: john.kennedy (at) metoffice.gov.uk
CRUTEM4 & HadCRUT4:
E-Mail: colin.morice (at) metoffice.gov.uk
ICDC / CEN / University of Hamburg
E-Mail: stefan.kern (at) uni-hamburg.de