University of Hamburg - to research, to teach, to educate and form, to homepage
ICDC
CENIntegrated Climate Data Center ICDC

Photo: getty images/L. Calvetti

Surface Temperature Anomalies from CRUTEM and HadCRUT

CRUTEM4
HEADCRUT4
CRUTEM4 variance adjusted remperature anomaly (top) and HadCRUT4 near-sureface temperature anomaly (bottom) on 16th January 2010. Copyright: UHH/CEN/AJB

Topics

Access

RESTRICTED:This link to the data set is only available for a restricted user group.  The data set is only accessible in CEN/MPI net or accessible from external nets with a customer account.  Please contact ICDC if you would like to access this data from outside the network.

  • View data at LAS: CRUTEM
  • View data at LAS: HadCRUT
  • Access data via OPeNDAP:  CRUTEM | HadCRUT
  • Data access via file system:
    • /data/icdc/atmosphere/crutem
    • /data/icdc/atmosphere/hadcrut

to top

Description

Long-term observations of near surface air temperature and sea surface temperature play a key role for climate system analysis.

CRUTEM5, HadCRUT5, and the 1961-1990 temperature climatology (Land: CRU, Jones et al. 1999, see references, Ocean: HadSST.3.1.0.0) which are offered via this website are gridded data sets of global historical land surface (and sea surface) temperature anomalies. HadCRUT5 and CRUTEM5 are from version 5.0.2.0. Data are available for each month since January 1850, on a 5 degree grid. The data sets are collaborative products of the Met Office Hadley Centre and the Climatic Research Unit at the University of East Anglia.

CRUTEM5 are limited to land stations; HadCRUT5 is a blend of the CRUTEM5 land-surface air temperature data set and the HadSST4 sea-surface temperature data set.

Common to all these data sets is that these display the anomaly of the respective observations relative to the period 1961-1990. First the anomaly of the station values is computed and then all anomalies are gridded into a 5° x 5° grid.

Last update of data set at ICDC: August 15, 2024

to top

Parameters

Parameters of CRUTEM and HadCRUT data sets.
NameUnitData Set
Surface air temperature anomaly [2m] K CRUTEM5 and HadCRUT5
Sea surface temperature anomaly [0m] K HadCRUT5
Number of observations per grid cell - CRUTEM5
Sampling error K CRUTEM5
Station error K CRUTEM5
Combined measurement and sampling error K CRUTEM5
Absolute 2 m air temperature (1961-1990 Climatology) °C CRU
Absolute SST [0 m] (1961-1990 Climatology) °C HadSST4

to top

Coverage, spatial and temporal resolution

Period and temporal resolution:

  • 1850-01 to 2024-06
  • monthly

Coverage and spatial resolution:

  • Global
  • 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)

Format:

  • NetCDF

to top

Data quality

The compilation of land air temperature records now includes more stations, and biases in sea surface temperature observations have been reduced. Improved methods of analysis and gridding extend the spatial coverage and reduce coverage biases and reduce uncertainty, especially in the period since 1960. New quality control proceedures are applied to screen for outliers in station data. The assessed uncertainties include those arising from thermometer accuracy, homogenisation, sampling of grid boxes with a finite number of measurements, large-scale biases such as urbanisation and estimation of regional averages with non-complete global measurement coverage.

For CRUTEM5 there are two versions. The "standard" CRUTEM5 uses the standard gridding method and is accompanied by an error model to provide estimates of the uncertainties in grid cell. Each grid-box value is the mean of all the station anomalies within that grid box. The "alternative" CRUTEM5alt uses a modified gridding method that removes the under-representation of high-latitude stations that occurs with the standard gridding method. Each station can contribute to multiple grid cells at the latitude of the station.There is no recommendation made as to which of the two should be used; we hence offer both.

For HadCRUT5 two data sets exist, the so-called "Analysis" and the so-called "non-infilled". The latter uses similar gridding methods as HadCRUT4, i.e. temperature anomaly values are estimated only in grid cells close to where we have measurements. HadCRUT5 Analysis estimates temperature anomalies using the spatial connectedness of temperature anomaly patterns. This extends the the geographical coverage by estimating temperature anomalies further from the available measurements. This improves the representation of less well observed regions in our estimates of global and hemispheric temperature change. We only offer the 200-member ensemble mean for "non-infilled" but we offer this mean and the 200 ensemble members for "Analysis".

For more information we refer to the references.

to top

Contact

HadSST4:
John Kennedy
Metoffice
email: john.kennedy (at) metoffice.gov.uk
phone: +44-1392-885105

CRUTEM5 & HadCRUT5:
Colin Morice
Metoffice
email: colin.morice (at) metoffice.gov.uk
phone: +44-1392-884566

Stefan Kern
University of Hamburg
email: stefan.kern (at) uni-hamburg.de

to top

References

Websites

to top

Data citation

Please cite the data as follows:

  • CRUTEM5: Osborne et al., 2021, J. Geophys. Res.-Atmos, 126, https://doi.org/10.1029/2019JD032352
  • HadCRUT5: Morice et al., 2021, J. Geophys. Res.-Atmos, 126, https://doi.org/10.1029/2019JD032361
  • HadSST4: Kennedy et al., 2019, J. Geophys. Res.-Atmos, 124, https://doi.org/10.1029/2018JD029867
  • CRU: Jones et al., 1999, Rev. Geophys., 37(2).

HadCRUT.[5.0.2.0] data were obtained from http://www.metoffice.gov.uk/hadobs/hadcrut5  on [August 7 2024] and are © British Crown Copyright, Met Office [year of first publication], provided under an Open Government License, http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

CRUTEM.[5] data were obtained from http://www.metoffice.gov.uk/hadobs/crutem5  on [August 7 2024] and are © British Crown Copyright, Met Office [year of first publication], provided under an Open Government License, http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/

and with the following acknowledgments:

Thanks to ICDC, CEN, University of Hamburg for data support.

to top

License

Please refer to the specified original sources for license information.

to top