Evaluation of nine gridded daily weather reconstructions for the European heatwave summer of 1807

作者：Peter Stucki, Stefan Brönnimann, Noemi Imfeld, Lucas Pfister, Conall E. Ruth, Yannis Valentin Schmutz, Yuri Brugnara, Martin Wegmann, Rajmund Przybylak, Janusz Filipiak · 年份：2025 · DOI：10.5194/egusphere-2025-5264 · 被引用次数：1 · 研究领域：Tree-ring climate responses、Geology and Paleoclimatology Research、Climate variability and models

Abstract. Recent research of early instrumental measurements combined with numerical-statistical techniques has contributed to global atmospheric reanalysis as well as regional products that cover pre-1850 weather. The advent of machine learning (ML) raises the question of how well we can reconstruct weather from the distant past using both established and emerging approaches. Here, we evaluate nine such approaches to reproduce the daily weather during Europe's hot summer of 1807. The datasets examined include the Twentieth Century Reanalysis (20CR) and enhanced versions (via additional assimilation, dynamical downscaling), an analog resampling product, as well as ML reconstructions that use neural networks (along with video-inpainting methods or variational auto-encoders). Validation is based on early station measurements, documentary information, statistical diagnostics, and a semi-quantitative assessment of atmospheric flow. We find that the summer of 1807 can be considered a prototype, pre-industrial heatwave summer, with three extremely hot episodes and maximum temperatures exceeding 30 – 35 °C in Central Europe. Most approaches achieve mean correlations (anomalies form the seasonal cycle) above 0.75 for temperature and centered Root Mean Square Error values below 3 °C, though variability tends to be underestimated. This speaks for overall robust reconstructions given the distant past and scarce underlying weather information. Skill scores for almost all reconstructions ...