Persistent ridging that occurs in the northern parts of the North Pacific is a major contributing factor in Alaska’s wintertime weather. In general, when a ridge axis is located in the Bering Sea, temperatures in Alaska are typically cooler than normal, however, when the ridge axis is located in the Gulf of Alaska, temperatures are well above normal. In this study the evolution of persistent ridging that occurs in a wide area stretching from the Kamchatka Peninsula to western Canada, is studied in the context of planetary waves.

Several authors have noted the importance that anomalies in either the amplitude or phase of planetary waves 1-4 have on the production of high amplitude ridging over the North Pacific. Essentially this is an attempt to clarify the role that planetary waves play in ridge evolution. In addition, the potential influence that stratospheric warmings as well as fluctuations in the position and strength of the East Asian jet, have on ridging is assessed.