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


Type

Article

Change log

Authors

Lai, AWC 
Graf, HF 

Abstract

Different types of El NiƱo (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 130ĀŗE-160ĀŗE Western Pacific 5m-250m subsurface oceanic potential temperature anomaly (PTA) about one year before the EN peak (typically January and February), and the 140ĀŗE-160ĀŗW 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 NiƱo regions can already be explained up to six months before the maximum SSTA occurs. This offers a rather simple potential for ENSO prediction.

Description

This is the author accepted manuscript. The final version is available via Springer at http://link.springer.com/article/10.1007%2Fs00382-015-2550-0.

Keywords

Central Pacific El Nino, El Nino 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 Science and Business Media LLC