CRUTEM

CRUTEM
Name	CRUTEM
Subject	Surface air temperature
Region	Global land
Developer	Hadley Centre; Climatic Research Unit
First release	1994
Latest release	ongoing
Format	Gridded anomalies
License	Academic use

CRUTEM

CRUTEM is a gridded surface air temperature dataset compiled by the Hadley Centre and the Climatic Research Unit to document historical temperature variations on land. It is widely used in assessments by institutions such as Intergovernmental Panel on Climate Change, Met Office Hadley Centre, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, and European Centre for Medium-Range Weather Forecasts. The dataset underpins analyses in publications by researchers at University of East Anglia, University of Oxford, Columbia University, Princeton University, and Massachusetts Institute of Technology.

Overview

CRUTEM combines station observations into gridded anomalies to create a globally consistent record compatible with products like datasets from Berkeley Earth, GISTEMP, and NOAA NCEI. Its development involved collaborations among groups including the Hadley Centre, Climatic Research Unit, University of Reading, and the Met Office. The dataset has been cited in reports of the Intergovernmental Panel on Climate Change and in peer-reviewed journals such as Nature, Science, Journal of Climate, Geophysical Research Letters, and Climate Dynamics.

Data and Methods

CRUTEM uses monthly mean temperature records from station networks maintained by agencies such as British Antarctic Survey, Australia Bureau of Meteorology, Environment and Climate Change Canada, China Meteorological Administration, India Meteorological Department, and Deutscher Wetterdienst. Stations are quality-controlled, homogenized, and combined into 5°×5° (and other) grids using anomaly-based techniques similar to methods used by Goddard Institute for Space Studies and Berkeley Earth. The processing pipeline includes steps referencing metadata from archives like International Surface Temperature Initiative and observational holdings of World Meteorological Organization. Statistical choices draw on methods discussed in literature from Royal Society, American Meteorological Society, European Geosciences Union, and researchers at University of Colorado Boulder and University of East Anglia.

Versions and Updates

Initial releases emerged in the mid-1990s, with major updates coordinated by teams at Hadley Centre and Climatic Research Unit to incorporate new station records, improved homogenization, and extended temporal coverage. Notable versioning paralleled updates in companion products such as CRUTEM4 and subsequent revisions that aligned with global products like HadCRUT and datasets developed jointly with National Center for Atmospheric Research and Met Office. Update drivers included digitization efforts by institutions like NOAA and archival recoveries by British Antarctic Survey, along with reanalyses from ERA-Interim and ERA5 produced by European Centre for Medium-Range Weather Forecasts.

Findings and Trends

Analyses using the dataset document 20th- and 21st-century warming patterns observed across continents and regions encompassed by station networks from Greenland, Siberia, Antarctica, Amazon Basin, and Sahara Desert. Published results reference amplified warming in high-latitude areas such as Arctic and regions affected by phenomena like El Niño–Southern Oscillation and North Atlantic Oscillation. Findings from CRUTEM-based studies appear alongside work by teams at NASA Goddard, NOAA National Centers for Environmental Information, Lawrence Berkeley National Laboratory, and Lamont–Doherty Earth Observatory documenting trends, extremes, and regional signatures tied to forcings discussed by researchers at Princeton University and University of Cambridge.

Comparisons and Criticism

Comparisons with products like GISTEMP, Berkeley Earth, NOAA GlobalTemp, and reanalyses such as ERA5 show broad agreement on long-term warming but reveal differences in regional trends, homogenization choices, and coverage-related uncertainties debated in papers by authors at University of East Anglia, University of Reading, Stockholm University, ETH Zurich, and University of Melbourne. Critiques have focused on station density, urban influences evaluated in studies of London, New York City, Tokyo, Beijing, and Mexico City, and on methods echoing discussions in forums of Royal Meteorological Society and journals like Bulletin of the American Meteorological Society. Responses to criticism led to methodological improvements referenced in work from Hadley Centre and Climatic Research Unit collaborators.

Uses and Impact

CRUTEM has informed synthesis assessments by the Intergovernmental Panel on Climate Change, national climate reports from United Kingdom Met Office, United States Global Change Research Program, and policy briefings for organizations including the United Nations Framework Convention on Climate Change and World Bank. It supports research at institutions like Scripps Institution of Oceanography, Woods Hole Oceanographic Institution, Potsdam Institute for Climate Impact Research, and Stockholm Environment Institute and underpins climate model evaluation at centers such as UK Met Office Hadley Centre, NOAA Geophysical Fluid Dynamics Laboratory, and Max Planck Institute for Meteorology. Its influence extends to educational resources used at universities including University of California, Berkeley, Harvard University, and Yale University.

Category:Climate datasets