Fig. 4: East Asian detrended circulation anomalies regressed on the 30-hPa standardized Quasi-Biennial Oscillation (QBO) index over the period 1995–2019.
From: A stratospheric precursor of East Asian summer droughts and floods
a East Asian geopotential height anomalies (colors, averaged over 70–120°E). b As in (a) but for the temperature anomalies (colors). c The 500-hPa vertical velocity anomalies (colors). d Vertical velocity anomalies averaged over 105-120°E (colors). e Vertically integrated moisture flux (vectors) and its divergence (colors) anomalies. f Observational precipitation anomalies (colors). g The 200-hPa zonal wind anomalies (colors) from historical stratospheric nudging experiments. h As in (g) but for precipitation anomalies (colors). i East Asian subtropical zonal wind anomalies (colors, averaged over 70–120°E, 15–27.5°N) lag-regressed on the standardized QBO index. NTA, SNA, and SIO indices are the weight-averaged SST anomalies over 0–80°W and 0–20°N, 0–60°W and 55–75°N, and 25–80°E and 35–50°S, respectively. The linear effects from NTA, SNA, and SIO have been removed in the anomalies in (a–f, i). Model results in (g–h) are averaged by 15 sets of historical stratospheric nudging experiments with different initial conditions, and each set of experiment runs for 25 years from 1995 to 2019. Dots indicate values at the 95% confidence level according to Student’s t-test.
