>MONTHLY SST ANOMALY MAP
The map of Global OI.v2 SST anomalies for April 2010 downloaded from the NOMADS website is shown below. The drop in central equatorial Pacific SST anomalies toward ENSO-neutral temperatures is obvious. The response should work its way eastward over the next couple of months.
April 2010 SST Anomalies Map (Global SST Anomaly = +0.32 deg C)
NINO3.4 SST anomalies are dropping but El Niño conditions remained during April in the central tropical Pacific (Monthly NINO3.4 SST Anomaly = +0.68 deg C). Weekly data has fallen into ENSO-neutral ranges (+0.30 deg C). Global SST anomalies increased slightly again during April (0.017 deg C). On a hemispheric basis, the rise was limited basically to the Northern Hemisphere, since the increase in the Southern Hemisphere was negligible (0.002 deg C). And looking at the major ocean basins, the North Pacific, South Atlantic, Indian Ocean, and the East Indian-West Pacific Ocean datasets all show drops this month, but they were not strong enough to outweigh the rises in the North Atlantic and South Pacific.
Monthly Change = +0.017 deg C
NINO3.4 SST Anomaly
Monthly Change = -0.46 deg C
EAST INDIAN-WEST PACIFIC
The SST anomalies in the East Indian and West Pacific have ended (temporarily) their lagged rise in response to the El Niño . Will they also rise, noticeably, in response to a La Niña as they have in the past? Will there even be a La Niña following this El Niño? Refer to Typical (Average) El Nino, Traditional El Nino, and El Nino Modoki Events.
I’ve added this dataset in an attempt to draw attention to the upward step response. 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 = -0.114 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 April 2009.
MONTHLY INDIVIDUAL OCEAN AND HEMISPHERIC SST UPDATES
Monthly Change = +0.036 deg C
Monthly Change = +0.002 deg C
North Atlantic (0 to 75N, 78W to 10E)
Monthly Change = +0.156 deg C
South Atlantic (0 to 60S, 70W to 20E)
Monthly Change = -0.037 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 = -0.083 Deg C
South Pacific (0 to 60S, 145 to 290E, where 290E=70W)
Monthly Change = +0.105 deg C
Indian Ocean (30N to 60S, 20 to 145E)
Monthly Change = -0.072 deg C
Arctic Ocean (65 to 90N)
Monthly Change = +0.024 deg C
Southern Ocean (60 to 90S)
Monthly Change = -0.109 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 +0.30 deg C. They’re working their way down. How low will they go?
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).