Separating Multi‐Decadal and Interannual Dynamics in the North Pacific‐Stratospheric Polar Vortex Relationship and Their Teleconnection to the North Atlantic

Abstract This study reveals distinct co‐variability between the North Pacific and the North Atlantic‐European (NAE) region at multi‐decadal and interannual timescales using reanalysis data. On interannual to decadal timescales, sea surface temperature (SST) anomalies in the North Pacific appear in phase with the traditional Pacific Decadal Oscillation (PDO), while in the tropics resemble El Niño‐Southern Oscillation (ENSO). The extratropical signal is the ENSO‐forced wave train in the troposphere correlating with a weaker stratospheric polar vortex. On multi‐decadal timescales (20–25 years), SST anomalies are stronger over the Kuroshio‐Oyashio Extension, and turbulent heat flux anomalies suggest a potential oceanic influence. The tropospheric teleconnection evolves differently through North America projecting onto the Pacific North American pattern, resulting in a stronger polar vortex. Consistently, the corresponding impacts on NAE surface climate are mostly out of phase. Results highlight the challenge of interpreting past and future trends in the Pacific‐NAE teleconnection.