Climate Dynamics

, Volume 25, Issue 4, pp 337–350

Evolution of ENSO-related rainfall anomalies in Southeast Asia region and its relationship with atmosphere–ocean variations in Indo-Pacific sector

Article

DOI: 10.1007/s00382-005-0031-6

Cite this article as:
Juneng, L. & Tangang, F.T. Climate Dynamics (2005) 25: 337. doi:10.1007/s00382-005-0031-6

Abstract

The Southeast Asia rainfall (SEAR) anomalies depend strongly on phases of El Niño (La Niña). Using an extended empirical orthogonal function (EEOF) analysis, it is shown that the dominant EEOF mode of SEAR anomalies evolves northeastward throughout a period from the summer when El Niño develops to spring the following year when the event weakens. This evolution is consistent with northeastward migration of the ENSO-related anomalous out going radiation field. During boreal summer (winter), the strong ENSO-related anomaly tends to reside in regions south (north) of the equator. The evolution of dominant mode of SEAR anomalies is in tandem with the evolution of ENSO-related sea surface temperature (SST) anomalies. The strengthening and weakening of “boomerang-shaped” SST in western Pacific, the changing sign of anomalous SST in Java Sea and the warming in Indian Ocean and South China Sea are all part of ENSO-related changes and all are linked to SEAR anomaly. The anomalous low-level circulation associated with ENSO-related SEAR anomaly indicates the strengthening and weakening of two off-equatorial anticyclones, one over the Southern Indian Ocean and the other over the western North Pacific. Together with patterns of El Niño minus La Niña composites of various fields, it is proposed that the northeastward evolution of SEAR anomaly is basically part of the large-scale eastward evolution of ENSO-related signal in the Indo-Pacific sector. The atmosphere–ocean interaction plays an important role in this evolution.

Keywords

Southeast Asia precipitation ENSO Seasonal variation Spatial variation 

Abbreviations

SEA

Southeast Asia

ENSO

El Niño–Southern Oscillation

SIO

South Indian Ocean

MC

Maritime Continent

DJF

December–January–February

JJA

June–July–August

SON

September–October–November

MAM

March–April–May

OLR

Outgoing long radiation

WNP

Western North Pacific

GHCN

Global Historical Climatology Network

HADiSST1

Version 1.1 of Hadley Cntre Global Ice and Sea Surface Temperature

UKMO

United Kingdom Meteorological Office

NCEP

National Center Environmental Prediction

SST

Sea surface temperature

SEAR

Southeast Asia rainfall

EEOF

Extended emprirical orthogonal function

ESVD

Extended singular value decomposition

BOB

Bay of Bengal

SCS

South China Sea

Copyright information

© Springer-Verlag 2005

Authors and Affiliations

  1. 1.Marine Science Program, School of Environmental & Natural Resource SciencesFaculty of Science & Technology National University of MalaysiaBangi SelangorMalaysia

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