Adding another Century to the Central European Temperature Record by Removing Early Instrumental Warm-Bias – A Windfall for Global Change Research
Preindustrial surface air temperature records contain biases that make their use for global change research difficult. Understanding and removing those biases would give scientists access to records prior to 1850, broadening current temperature records to a multi-centennial scale. DOE-funded scientist Phil Jones (University of East Anglia in Norwich, UK) and his colleagues have succeeded in creating an instrumental temperature record for the Greater Alpine Region (GAR) in central Europe beginning in the year 1760 by accounting for changes in how instruments were inadequately protected from direct sunlight prior to 1850-1870, when new screening procedures were put in place. Lack of adequate protection caused temperatures in the summer to be biased warm and those in the winter to be biased cold. Removal of those systematic errors was the key to creating this valuable, new, expanded data resource. The results also have broader implications for the calibration of historical proxy climatic data in the region such as tree ring indices and documentation of grape harvest dates.
Böhm, R., P. D. Jones, J. Hiebl, D. Frank, M. Brunetti, and M. Maugeri. 2009. “The Early Instrumental Warm-Bias: A Solution for Long Central European Temperature Series, 1760-2007,” Climatic Change 101(1–2), 41–67. DOI: 10.1007/s10584-009-9649-4.