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Tropical Pacific Oceanic Conditions during 2004-2006. John Janowiak Climate Prediction Center/NCEP/NWS. OCO Annual Review - May 11, 2006. SST Evolution. Evolution of Equatorial Pacific SST Anomalies. Departures increased substantially in the central equatorial Pacific during July 2004.
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Tropical Pacific Oceanic Conditions during 2004-2006 John Janowiak Climate Prediction Center/NCEP/NWS OCO Annual Review - May 11, 2006
Evolution of Equatorial Pacific SST Anomalies • 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 Time June 2005 Longitude
May 2004 Aug 2004 Nov 2004 Evolution of Equatorial Pacific SST Anomalies
Feb 2005 May 2005 Aug 2005 Evolution of Equatorial Pacific SST Anomalies
Evolution of Equatorial Pacific SST Anomalies Nov 2005 Feb 2006
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 operationaldefinitions of El Niño and La Niña are keyed to the index.
NOAA Operational Definitions for El Niño and La Niña El Niñoconditions: positive ONI > = +0.5°C. La Niñaconditions; negative ONI < = -0.5°C. For historical record, episode is classified as a full-fledged El Niño or La Niña episode when thresholds have been exceeded for at least 5 consecutive months.
Year DJF JFM FMA MAM AMJ MJJ JJA JAS ASO SON OND NDJ 2002 -0.1 0.1 0.3 0.4 0.7 0.8 0.9 0.9 1.1 1.3 1.5 1.3 2003 1.1 0.8 0.6 0.1 -0.1 0.0 0.3 0.4 0.5 0.5 0.6 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 Recent ONI Values 0.5 0.8 0.4 0.2 0.2 0.2 0.3 0.4 0.7 0.8 0.9 0.9 0.9 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?
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(5N-5S) • * MJO active • + Precip. anoms • restricted to west • of date line
active MJO inactive
This was a mid-Pacific event & thus the OLR index (160oE-160oW) near-neutral …
Summary • A weak El Niño event occurred during mid-2004 thru early 2005, accompanied by active MJO • The event was limited mostly to the mid-Pacific • Transition to cooler-than-normal SST by Nov 2005 • Weak La Niña conditionsduring Nov 2005 – Mar 2006