Fig. 11: Interannual atmospheric controls on Meiyu season δ¹⁸O at Nanjing.

a Correlation between amount-weighted mean Meiyu season δ¹⁸O and Meiyu season mean P_{acc_2d} (2012-2021, derived from IMERG). b Correlation between amount-weighted mean June-July δ¹⁸O and precipitation amount (1987–1992 and 2012–2021, derived from CMFD). c Correlation between amount-weighted mean June-July δ¹⁸O and 500 hPa geopotential height (1987–1992 and 2012–2021). Dotted areas indicate where the correlations do not pass the 90% significance level. In (c), thick black contours show the western Pacific subtropical high (WPSH; 5860/5880 gpm) in 2019 (highest June-July δ¹⁸O), and brown contours show 2016 (lowest June-July δ¹⁸O). The black stars denote the location of Nanjing. The black lines depict the Meiyu region boundaries. Maps created using Cartopy. Coastlines are from the Natural Earth public domain dataset. The Meiyu boundaries were processed in QGIS based on the Meiyu Monitoring Dataset.