>MONTHLY SST ANOMALY MAP
The map of Global OI.v2 SST anomalies for July 2010 downloaded from the NOMADS website is shown below. The central equatorial Pacific SST anomalies have decreased well below the threshold of a La Niña. Tropical Atlantic SST anomalies are still elevated but have dropped significantly in recent months.
July 2010 SST Anomalies Map (Global SST Anomaly = +0.22 deg C)
Monthly NINO3.4 SST anomalies are well into the range of a La Niña, which is -0.5 deg C. The Monthly NINO3.4 SST Anomaly is -0.99 deg C. Weekly data has made a slight uptick for the first time in this transition, but it is still less than -1.0 deg C (-1.102 deg C).
Global SST anomalies have resumed their decline. The seasonal decline in the Southern Hemisphere (-0.076 deg C) was greater than the seasonal rise in the Northern Hemisphere (+0.030 deg C).
Monthly Change = -0.030 deg C
NINO3.4 SST Anomaly
Monthly Change = -0.49 deg C
EAST INDIAN-WEST PACIFIC
The SST anomalies in the East Indian and West Pacific made a significant rise this month. Will they continue to rise, noticeably, in response to the 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 = +0.019 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
The animations included in post La Niña Is Not The Opposite Of El Niño – The Videos further help explain the reasons why East Indian and West Pacific SST anomalies can rise in response to both El Niño and La Niña events.
NOTE ABOUT THE DATA
The MONTHLY graphs illustrate raw monthly OI.v2 SST anomaly data from November 1981 to July 2010.
MONTHLY INDIVIDUAL OCEAN AND HEMISPHERE SST UPDATES
Monthly Change = +0.030 deg C
Monthly Change = -0.076 deg C
North Atlantic (0 to 75N, 78W to 10E)
Monthly Change = +0.030 deg C
South Atlantic (0 to 60S, 70W to 20E)
Monthly Change = -0.081 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 = +0.040 Deg C
South Pacific (0 to 60S, 145 to 290E, where 290E=70W)
Monthly Change = -0.113 deg C
Indian Ocean (30N to 60S, 20 to 145E)
Monthly Change = -0.020 deg C
Arctic Ocean (65 to 90N)
Monthly Change = +0.079 deg C
Southern Ocean (60 to 90S)
Monthly Change = +0.024 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 -1.102 deg C.
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).