Fig. 7: Mechanisms linking decadal HWCI fluctuations to decadal oceanic variability.
From: Decadal oceanic variability amplified recent heatwave in the Northern Hemisphere
a Composite 200 hPa geopotential height (Z200) anomalies and wave activity fluxes for the positive AMO minus the negative AMO phases for 1942–2021. The white dots indicate significant correlations at the 95% confidence level (two-sided P < 0.05), assessed with a random-phase resampling test55. The arrows represent the pathways of Rossby wave trains linking the positive AMO to Northern Hemisphere heatwaves, based on T-N wave activity flux54 (see Methods) and as shown in Fig. S8. b Same as a but for the negative IPO minus the positive IPO phases. c Schematic of wave activity flux pathways induced by the positive AMO and the negative IPO.
