Tropical Pacific Oceanic Conditions during 2004-2006

Tropical Pacific Oceanic Conditions during 2004-2006

John Janowiak Climate Prediction Center/NCEP/NWS

OCO Annual Review - May 11, 2006

SST EvolutionSST Evolution

Evolution of Equatorial Pacific SST Evolution of Equatorial Pacific SST AnomaliesAnomalies

Longitude

Time

•Departures increased substantially in the central equatorial Pacific during July 2004.

• The warmth in the central equatorial Pacific expanded eastward during July-October 2004.

• The warmth in the equatorial Pacific persisted during November-December 2004.

• Cooling occurred east of the date line during February.

• Warming occurred in the eastern equatorial Pacific during April through early May .

July 2004

June 2005

Evolution of Equatorial Pacific SST Evolution of Equatorial Pacific SST AnomaliesAnomalies

May 2004 Aug 2004 Nov 2004

Evolution of Equatorial Pacific SST Evolution of Equatorial Pacific SST AnomaliesAnomalies

Feb 2005 May 2005 Aug 2005

Evolution of Equatorial Pacific SST Evolution of Equatorial Pacific SST AnomaliesAnomalies

Nov 2005 Feb 2006

SST Index SST Index

Oceanic Niño Index (ONI)Oceanic Niño Index (ONI)

• Three-month running-mean of SST anomalies over the Niño 3.4 region

• Used to place current conditions in historical perspective

• NOAA operational definitions of El Niño and La Niña are keyed to the index.

NOAA Operational Definitions for NOAA Operational Definitions for El Niño and La NiñaEl Niño and La Niña

El Niño conditions: positive ONI > = +0.5°C.

La Niña conditions; negative ONI < = -0.5°C.

For historical record, episode is classified as a full-fledged El Niño or La Niña episode when thresholds havebeen exceeded for at least 5 consecutive months.

Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ2002 -0.1 0.1 0.3 0.4 0.7 0.8 0.9 0.9 1.1 1.3 1.5 1.32003 1.1 0.8 0.6 0.1 -0.1 0.0 0.3 0.4 0.5 0.5 0.6200420052006200720082009201020112012201320142015201620172018201920202021202220232024202520262027

0.50.4 0.2 0.2 0.2 0.3 0.4 0.7 0.8 0.9 0.9 0.9 0.8

0.6 0.5 0.3 0.4 0.5 0.3 0.2 0.0 0.0 -0.2 -0.4 -0.7-0.8 -0.7 -0.4?

Recent ONI ValuesRecent ONI Values

....

(5N-5S)

* MJO active

•+ Precip. anoms restricted to west of date line

MJO

active

inactive

This was a mid-Pacific event & thus the OLR index (160oE-160oW) near-neutral …

SummarySummary

• A weak El NiA weak El Niño event occurred during mid-2004 thru early 2005, ño event occurred during mid-2004 thru early 2005,

accompanied by active MJOaccompanied by active MJO

• The event was limited mostly to the mid-Pacific The event was limited mostly to the mid-Pacific

• Transition to cooler-than-normal SST by Nov 2005Transition to cooler-than-normal SST by Nov 2005

• Weak La Niña Weak La Niña conditionsconditions during Nov 2005 – Mar 2006during Nov 2005 – Mar 2006