>MONTHLY SST ANOMALY MAP
The map of Global OI.v2 SST anomalies for May 2010 downloaded from the NOMADS website is shown below. The central equatorial Pacific SST anomalies have decreased considerably since their peak in December and are now below zero. SST anomalies in most oceans basins are now dropping in response.
May 2010 SST Anomalies Map (Global SST Anomaly = +0.25 deg C)
NINO3.4 SST anomalies have dropped into ENSO-neutral conditions. The central tropical Pacific (Monthly NINO3.4) SST Anomaly is -0.09 deg C. Weekly data has fallen well into ENSO-neutral ranges (-0.32 deg C) and are approaching the threshold of a La Niña.
Global SST anomalies dropped 0.066 deg C during May. The decline in the Southern Hemisphere (-0.081 deg C) exceeded the drop in the Northern Hemisphere (-0.046 deg C). SST anomalies dropped in all ocean basins except for the Arctic.
Monthly Change = -0.066 deg C
NINO3.4 SST Anomaly
Monthly Change = -0.77 deg C
EAST INDIAN-WEST PACIFIC
The SST anomalies in the East Indian and West Pacific continue their decrease also. Will they rise, noticeably, in response to a La Niña as they have in the past?
I’ve added this dataset in an attempt to draw attention to what appears to be the upward step responses. Using the 1986/87/88 and 1997/98 El Niño events as references, East Indian-West Pacific SST Anomalies peak about 7 to 9 months after the peak of the NINO3.4 SST anomalies, so we shouldn’t expect any visible sign of a step change for almost 18 to 24 months. We’ll just have to watch and see.
East Indian-West Pacific (60S-65N, 80E-180)
Monthly Change = -0.032 deg C
Further information on the upward “step changes” that result from strong El Niño events, refer to my posts from a year ago Can El Niño Events Explain All of the Global Warming Since 1976? – Part 1 and Can El Niño Events Explain All of the Global Warming Since 1976? – Part 2
And for the discussions of the processes that cause the rise, refer to More Detail On The Multiyear Aftereffects Of ENSO – Part 2 – La Niña Events Recharge The Heat Released By El Niño Events AND…During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents -AND- More Detail On The Multiyear Aftereffects Of ENSO – Part 3 – East Indian & West Pacific Oceans Can Warm In Response To Both El Niño & La Niña Events
NOTE ABOUT THE DATA
The MONTHLY graphs illustrate raw monthly OI.v2 SST anomaly data from November 1981 to May 2009.
MONTHLY INDIVIDUAL OCEAN AND HEMISPHERIC SST UPDATES
Monthly Change = -0.046 deg C
Monthly Change = -0.081 deg C
North Atlantic (0 to 75N, 78W to 10E)
Monthly Change = -0.058 deg C
South Atlantic (0 to 60S, 70W to 20E)
Monthly Change = -0.099 deg C
Note: I discussed the upward shift in the South Atlantic SST anomalies in the post The 2009/10 Warming Of The South Atlantic.
North Pacific (0 to 65N, 100 to 270E, where 270E=90W)
Monthly Change = -0.059 Deg C
South Pacific (0 to 60S, 145 to 290E, where 290E=70W)
Monthly Change = -0.081 deg C
Indian Ocean (30N to 60S, 20 to 145E)
Monthly Change = -0.074 deg C
Arctic Ocean (65 to 90N)
Monthly Change = +0.039 deg C
Southern Ocean (60 to 90S)
Monthly Change = -0.089 deg C
WEEKLY NINO3.4 SST ANOMALIES
The weekly NINO3.4 SST anomaly data illustrate OI.v2 data centered on Wednesdays. The latest weekly NINO3.4 SST anomalies are -0.35 deg C. And NOAA has posted a La Niña watch.
Weekly NINO3.4 (5S-5N, 170W-120W)
The Optimally Interpolated Sea Surface Temperature Data (OISST) are available through the NOAA National Operational Model Archive & Distribution System (NOMADS).