Cause for quasi-biweekly oscillation of zonal location of western Pacific subtropical high during boreal summer

The cause for zonal oscillation of the western Pacific subtropical high (WPSH) on a quasi-biweekly (10–20-day) timescale was investigated. Both relative vorticity and geopotential height anomalies exhibit a maximum activity center over the western edge of the climatological WPSH. The quasi-biweekly WPSH oscillation is closely related to a northwestward-propagating quasi-biweekly oscillation (QBWO) mode over the western North Pacific (WNP). A...