Seasonal climate impacts on the grape harvest date in Burgundy (France)

Abstract

Abstract. In this study, we analyse the climatic impacts on the grape harvest date (GHD) in Burgundy (France) on interannual and decadal time scales. We affirm that the GHD is mainly influenced by the local April-to-August temperature (AAT) and provide the spatial expansion of this relationship. The spatial correlation pattern yields similar results for the instrumental and pre-instrumental period, indicating the consistency of the pre-instrumental field data with the instrumental GHD-spring/summer relationship. We find a previously undocumented second climate impact on the GHD. The winter temperature is significantly correlated with the GHD on decadal-to-multidecadal time scales and affects the GHD independently of the AAT. A multiple linear regression model, with AAT and decadal winter temperature as predictors, was found to be the best model to describe the GHD time series for the instrumental period. Stability tests of the correlations over time yield that both impacts on the GHD, AAT and decadal winter temperature, strengthen during the instrumental period. Using partial correlation analysis, we demonstrate that this is partly caused by a change in the winter-spring/summer temperature relationship. Summarising, the GHD is well suited to reconstruct interannual variations of the spring/summer temperature over large parts of Europe, even if the changing winter-spring/summer relation might affect the reconstruction in a second order. For decadal time scales, the December-to-August temperature shows the strongest relationship to the GHD and, therefore, proposes that the GHD can be used for European temperature reconstructions beyond the spring/summer season. Finally, we argue that our findings regarding the changed Correspondence to: M. Krieger (kriegerm@uni-bremen.de) winter-spring/summer relation are relevant for physical and biological systems in several ways and should be analysed by other long-term proxy data and available model simulations.

The longest homogeneous series of grape harvest dates, Beaune 1354–2018, and its significance for the understanding of past and present climate

“…First, the "Dijon series" is riddled with printing, typing and copying errors. The investigation of the original archives from the city council in Dijon shows 132 differences with the Angot series for the period 1385 to 1879 (Labbé and Gaveau, 2011). The mismatches reach 5-10 d for 17 years, 10-20 d on nine occasions, and more than 20 d in 1448, 1522, 1523, 1540, 1659, 1660 and 1842.…”

“…Despite an exhaustive investigation in the local archives, 61 dates for Beaune are still missing before 1645. To fill in these lacunae, when possible we used the evidence of the corrected Dijon series (Labbé and Gaveau, 2011), taking into account the mean difference of days between the two raw series.…”

“…The heatwave of 1540 undoubtedly struck the region of Burgundy. The church of Notre-Dame of Beaune organised eight processions to call for rains from the beginning of May to the end of August (Labbé and Gaveau, 2011). In the near city of Besançon (ca.…”

“…. Geographical area of the study (taken from Amante and Eakins, 2019). 2007; Krieger et al, 2011;Garcia de Cortázar-Atauri et al, 2010;Daux et al, 2012;Rousseau, 2015). In the literature, the GHD series from the town of Dijon, situated in Burgundy (France; see Fig.…”

“…First, scholars have until now uncritically drawn on the data from 19th century publications. The original data of the Dijon series have been recently revisited directly in the local archives (Labbé and Gaveau, 2011), and this reassessment makes it obvious that the formerly published "Dijon series" is thoroughly unreliable due to compilation errors. Secondly, the available Burgundian GHD dataset is not homogeneous.…”