Figure 1
From: Land-surface initialisation improves seasonal climate prediction skill for maize yield forecast
Combined Stress Index and maize yield in Europe from 1981 to 2010. (a) Time series of standardised observed maize yield anomalies. In each year, the country based values are superimposed onto each other to form a stacked barplot; colours are associated with countries. Asterisks denote the first year of available maize yield records. The time series on graphs (b–e) are calculated for all countries during the entire period 1981–2010. (b) CSI time series are derived from the E − OBS observational dataset. In each year, the CSI values are superimposed onto each other to form a stacked barplot; colours are associated with countries. (c) Time series of heat degree days (HDD) in country-specific maize crop growing areas. (d) Time series of standardised precipitation evapotranspiration index (SPEI) in country-specific maize crop growing areas. (e) Fraction of maize production areas in countries with significant CSI models (see Table 1), affected by drought only (\(SPE{I}_{opt,t}^{\ast }\) less than −1 and \(HD{D}_{JJA,t}^{std{,}^{\ast }}\) less than 1), heat wave only (\(SPE{I}_{opt,t}^{\ast }\) higher than −1 and \(HD{D}_{JJA,t}^{std{,}^{\ast }}\) higher than 1) or combined effect of heat and drought (\(SPE{I}_{opt,t}^{\ast }\) less than −1 and \(HD{D}_{JJA,t}^{std{,}^{\ast }}\) higher than 1).
