Generation mechanism of quasidecadal variability of upper ocean heat content in the equatorial Pacific Ocean

Abstract

We investigate the relationship between oceanic and atmospheric anomaly fields in the tropical Pacific on the quasidecadal (QD; 10 to 18 years) scale is explored. It is suggested that the anomalous wind stress curt in the tropical South Pacific can generate the equatorial upper ocean heat content (OHC) anomalies on the QD scale via the Sverdrup transport resembling that of the recharge-discharge oscillator model for the dynamics of El Niño-Southern Oscillation (ENSO). The results also show that the wind stress curl anomalies in the tropical South Pacific are accompanied by ENSO-like, QD-scale anomaly patterns of the sea level pressure and sea surface temperature. Furthermore, the results indicate that the equatorial QD-scale OHC anomalies can also be generated by the ENSO-like propagations of the OHC anomalies in the tropical North and South Pacific. This study presents a systematic linkage between the ENSO-like, QD-scale OHC propagation in the tropical North and South Pacific, the Sverdrup transport variation in the tropical South Pacific, and the ENSO-like, QD-scale SST and SLP anomalies in the tropical Pacific. Copyright 2007 by the American Geophysical Union.