North Pacific Oscillation

The North Pacific Oscillation (NPO) is a teleconnection pattern first described by Walker and Bliss and characterized by a north-south seesaw in sea level pressure over the North Pacific.
Rogers, using surface atmospheric temperature from St. Paul, Alaska and Edmonton, identified two phases of the NPO, an Aleutian below (AB) phase that correspond to a deepened and eastward shifted Aleutian low and an Aleutian above (AA) phase that is the opposite.