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

This paper investigates the interdecadal variability in the lagged relationship between the spring Victoria mode(VM)and the following-winter El Ni?o–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,and2005–2008.The surface air–sea coupling and the evolution of subsurface ocean temperature anomaliesh along the equatorial Paci?c 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 in?uenced by the North Paci?c Oscillation.Our?ndings may improve the prediction skill for the onset of ENSO events.

本文利用1900–2016年的逐月资料,通过相关分析、合成分析等气象统计方法,探讨了VM与ENSO关系的年代际变化。结果表明两者存在显著的年代际变化。在高相关时期,与VM相关的表面海气耦合和沿赤道的次表面海温演变过程均强于低相关时期,导致在高相关时期VM对ENSO的影响更强。此外,进一步分析表明VM-ENSO关系的年代际变化的原因主要是由于VM强度的年代际变化引起的,而VM强度的变化受到北太平洋涛动(NPO)的影响。本文的研究有助于提高ENSO的预报技巧,对于完善ENSO预报的理论框架有进一步的帮助。