Continental atmospheric circulation over Europe during the Little Ice Age inferred from grape harvest dates

Abstract. Estimates of climate conditions before the 19th century are based on proxy data reconstructions or sparse meteorological measurements. The reconstruction of the atmospheric circulation that prevailed during the European Little Ice Age (∼1500–1850) has fostered many efforts. This study illustrates a methodology, combining historical proxies and modern datasets to obtain detailed information on the atmospheric circulation that prevailed over the North Atlantic region during the Little Ice Age. We used reconstructions of temperature gradients over France based on grape harvest dates to infer the atmospheric circulation. We found that blocking situations were more likely in summer, inducing a continental atmospheric flow. This study advocates that the reconstructions of the past atmospheric circulation should take this regime into account.