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Two key parameters for the El Niño continuum: Zonal wind anomalies and Western Pacific subsurface potential temperature


Type

Article

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Authors

Lai, Andy Wang-Chun 
Graf, Hans-Friedrich 

Abstract

Different types of El Niño (EN) events have recently been discussed. Based on NCEP-NOAA reanalysis data this analysis explores a number of key parameters that cause a range of EN types over the period 1980-2013. EN events are divided into three types depending on the spatial and temporal evolution of the sea surface temperature anomalies (SSTA): Central Pacific (CPEN), Eastern Pacific (EPEN), and Hybrid (HBEN). We find that EN is a continuous spectrum of events with CPEN and EPEN as the end members. This spectrum mainly depends on two key parameters: the 130ºE-160ºE Western Pacific 5m-250m subsurface oceanic potential temperature anomaly (PTA) about one year before the EN peak (typically January and February), and the 140ºE-160ºW cumulative zonal wind anomaly (ZWA) between onset and peak of the EN event. Using these two parameters, about 70% of the total variance of the maximum SSTA realised in different Niño regions can already be explained up to six months before the maximum SSTA occurs. This offers a rather simple potential for ENSO prediction.

Description

Keywords

Central Pacific El Niño, El Niño continuum, Zonal wind anomalies, Oceanic potential temperature, Thermocline discharge-recharge state

Journal Title

Climate Dynamics

Conference Name

Journal ISSN

0930-7575
1432-0894

Volume Title

45

Publisher

Springer