The Forcing of the Pacific Decadal Oscillation*

• DOI: 10.1175/jcli3527.1
• Publication Date: 2005-11-28T22:00:17Z
• Authors: Niklas Schneider; Bruce D. Cornuelle
• Keywords: Empirical orthogonal functions; Forcing (mathematics); Ekman transport; Oscillation (cell signaling); Sea-surface height

Abstract The Pacific decadal oscillation (PDO), defined as the leading empirical orthogonal function of North sea surface temperature anomalies, is a widely used index for variability. It shown that PDO can be recovered from reconstruction anomalies based on first-order autoregressive model and forcing by variability Aleutian low, El Niño–Southern Oscillation (ENSO), oceanic zonal advection in Kuroshio–Oyashio Extension. latter results Rossby waves are forced Ekman pumping. SST response patterns to these processes not orthogonal, they determine spatial characteristics PDO. importance different frequency dependent. At interannual time scales, ENSO low determines equal parts. Extension, ENSO, each account similar amounts variance. These support hypothesis dynamical mode, but arises superposition fluctuations with origins.