Fig. 2: The Great Famine and the Great Famine mode.

a Three-year moving average of the principal component (PC) time series of the leading mode of variability over the OWDA, identified as the GFM, and 3-year moving average of scPDSI over Europe (defined as “All Countries,” in Table 1, which excludes Italy) from 1300 to 2012 (both time series have been normalized to unit variance). Red (black) dashed line marks the normalized GFM PC (European scPDSI) value during the Great Famine years of 1314–1316. The Pearson’s correlation coefficient between the GFM PC and scPDSI from 1300 to 2012 is provided in the lower right corner. Gray vertical lines mark famine years (identified only up to 1710). b The leading empirical orthogonal function (EOF) of the GFM in the OWDA from 1300 to 2012. The variance explained by the GFM is provided below the map. c Composite of the annual extreme wet anomalies from 1300 to 2012, defined as the years when the average scPDSI value over Europe is ≥1 (N = 58 years). d Composite of extreme dry anomaly years from 1300 to 2012, defined as the years when the average scPDSI value over Europe is ≤−1 (N = 130 years).