Interdecadal change in the lagged relationship between the Victoria mode and ENSO

Abstract

This paper investigates the interdecadal variability in the lagged relationship between the spring Victoria mode (VM) and the following-winter El Niño–Southern Oscillation (ENSO). It is found that the relationship is strong during high correlation (HC) periods, e.g. 1957–1964 and 1981–2004, but weak during low correlation (LC) periods, e.g. 1907–1924, 1926–1956, 1965–1980, and 2005–2008. The surface air–sea coupling and the evolution of subsurface ocean temperature anomaliesh along the equatorial Pacific associated with the VM are found to be strong during HC periods and weak during LC periods, which results in a stronger impact of the VM on the following-winter ENSO during HC periods. The interdecadal change in the relationship between the VM and ENSO is mainly due to the interdecadal change in the intensity of the VM, which is found to be influenced by the North Pacific Oscillation. Our findings may improve the prediction skill for the onset of ENSO events.

Keywords

• Victoria mode
• ENSO
• interdecadal change
• North Pacific Oscillation