Figure 1

(a) Climatology (contour, unit: gpm) and standard deviation (shaded, unit: gpm) of summer 200 hPa geopotential height during 1948–2016. (b) Normalized time series of the South Asian High (SAH) index (green bar) and the Silk Road teleconnection pattern (SRP) index (black line). (c) Sliding correlation between the SAH index and the SRP index at the central year of a 17-yr window. (d) Regression of the 200 hPa geopotential height anomalies (black contour, where the contour interval (CI) is 5 gpm) and the wave activity flux (vectors, unit: m² s⁻²) on the summer SAH index. (e) Regression of the 200 hPa geopotential height anomalies (black contour, where the CI is 5 gpm) and the wave activity flux on the SRP index. The horizontal dashed line indicates the 95% confidence level of correlation in (c). The dark (light) shadings in (d,e) indicate geopotential height anomalies significant at the 99% (95%) confidence level. Wave activity fluxes are omitted when both directions are less than 0.5 m² s⁻² in (d,e). This Figure is created by the NCL⁵⁸ v6.4.0 (http://www.ncl.ucar.edu/).