Science Source

Preconditioning of Arctic Stratospheric Polar Vortex Shift Events

Examines the preconditioning of events in which the Arctic stratospheric polar vortex shifts toward Eurasia (EUR events), North America (NA events), and the Atlantic (ATL events) using composite analysis
Finds that a decrease in blocking days over northern Europe and an increase in blocking days over the Bering Strait favors the movement of the vortex toward North America
Further defines three types of tropospheric blocking events in which the spatial patterns of blocking frequency anomalies are similar to the blocking patterns prior to EUR, NA, and ATL events, respectively
Reanalysis reveals that the polar vortex is indeed more likely to shift toward Eurasia, North America, and the Atlantic in the presence of the above three defined tropospheric blocking events