Eastward surface jets in the central equatorial Pacific, November 1991-March 1992

摘要

The central equatorial Pacific typically has westward surface and near-surface flow, interrupted by periods of eastward flow. The processes that may have been responsible for two periods of eastward flow during the 1991-92 El Nino between October 1991 and March 1992 are explored here, based on realistic hindcasts from a high-vertical resolution ocean general circulation model. The model balances indicate that the November-December 1991 surface trapped jet is fully nonlinear, and both wind stress and horizontal pressure gradient forcing are significant. The January-February 1992 jet is less strongly nonlinear. Both jets are strongly affected by local and remote westerly wind event forcing.