Maps of the northern (left) and southern (right) hemispheres showing temperature anomalies relative to the 1961–1990 mean for the month of August 2016 using an alternative gridding method
Gridded temperature anomaly (degrees C relative to the 1961–1990 mean) maps for the month of August 2016 as an example of the alternative gridding method in the northern (left) and southern (right) hemispheres. Credit: Osborn et al. [2021], Figure 5, top two panels from right column
Source: Journal of Geophysical Research: Atmospheres

CRUTEM (Climatic Research Unit temperature) is a high-profile global land-surface temperature dataset which has formed the basis of observed global warming over land over the past century and a half. Osborn et al. [2021] discuss a major update to the dataset (CRUTEM5), which extends the time period from the previous range of 1850-2011 to 1850-2019. It also includes measurements from more than 3000 additional stations and uses improved methods of quality control and gridding algorithms. The global, annual-mean land temperature has increased by 1.6°C from 1861-1900 to the mean of the last 5 years (for comparison, the uncertainty on individual annual means is only -0.11°C to +0.10°C in recent years). The dataset can be used to study both global and regional climate variabilities and changes.

Citation: Osborn, T. J., Jones, P. D., Lister, D. H., Morice, C. P., Simpson, I. R., Winn, J. P., et al. [2021]. Land surface air temperature variations across the globe updated to 2019: the CRUTEM5 dataset. Journal of Geophysical Research: Atmospheres, 126, e2019JD032352.

—Minghua Zhang, Editor-in-Chief, JGR: Atmospheres

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