July 2011 Sea Surface Temperature (SST) Anomaly Update

INITIAL NOTE

I’ve changed the coordinates used for North Atlantic SST anomalies. I had been using 0-75N, 78W-10E, but I’ve changed them to the coordinates used by the NOAA ESRL for their Atlantic Multidecadal Oscillation (AMO) data, 0-70N, 80W-0.

North Atlantic SST Anomaly Comparison

MONTHLY SST ANOMALY MAP

The following is a Global map of Reynolds OI.v2 SST anomalies for July 2011 downloaded from the NOMADS website. The contour levels are set at 0.5 deg C, and white is set at zero. Note the Hot Spot in the North Pacific–it’s tough to miss, actually. I’m preparing a post about it to dispel any concerns. It’s not unusual.

July 2011 SST Anomalies Map (Global SST Anomaly = +0.146 deg C)

MONTHLY OVERVIEW

Monthly NINO3.4 SST anomalies are still below zero. The Monthly NINO3.4 SST Anomaly dropped to -0.118 deg C.

The slight rise in the SST anomalies for the Northern Hemisphere this month were more than countered by the drop in Southern Hemisphere SST anomalies, so global SST anomalies dropped slightly in July. The Global SST anomalies are presently at +0.146 deg C.

(1) Global

Monthly Change = -0.022 deg C

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(2) NINO3.4 SST Anomaly

Monthly Change = -0.085 deg C

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THE EAST PACIFIC VERSUS THE REST OF THE WORLD

The East Pacific and the Rest-Of-The-World (Atlantic-Indian-West Pacific) datasets were first discussed in the post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World.Both datasets have been adjusted for the impacts of volcanic aerosols. The global oceans were divided into these two subsets to illustrate two facts. First, the linear trend of the volcano-adjusted East Pacific (90S-90N, 180-80W) SST anomalies since the start of the Reynolds OI.v2 dataset is basically flat. The East Pacific linear trend varies with each monthly update. But it won’t vary significantly between El Niño and La Niña events.

(3) Volcano-Adjusted East Pacific (90S-90N, 180-80W)

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And second, the volcano-adjusted SST anomalies for the Rest of the World (90S-90N, 80W-180) rise in very clear steps, in response to the significant 1986/87/88 and 1997/98 El Niño/La Niña events. It also appears as though the SST anomalies of this dataset are making another shift in response to the most recent ENSO event. For those who are interested in the actual trends of the SST anomalies between the 1986/87/88 and 1997/98 El Niño events and between the 1997/98 and 2009/10 El Niño events refer to Figure 4 in Does The Sea Surface Temperature Record Support The Hypothesis Of Anthropogenic Global Warming? I further described (at an introductory level) the ENSO-related processes that cause these upward steps in the post ENSO Indices Do Not Represent The Process Of ENSO Or Its Impact On Global Temperature.

(4) Volcano-Adjusted Rest of the World (90S-90N, 80W-180)

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The periods used for the average Rest-Of-The-World SST anomalies between the significant El Niño events of 1982/83, 1986/87/88, 1997/98, and 2009/10 are determined as follows. Using the NOAA Oceanic Nino Index(ONI) for the official months of those El Niño events, I shifted (lagged) those El Niño periods by six months to accommodate the lag between NINO3.4 SST anomalies and the response of the Rest-Of-The-World SST anomalies, then deleted the Rest-Of-The-World data that corresponds to those significant El Niño events. I then averaged the Rest-Of-The-World SST anomalies between those El Niño-related gaps.

The “Nov 2010 to Present” average varies with each update. As noted in the linked post, it will be interesting to see where that SST anomaly average settles out, if it does, before the next significant El Niño drives them higher.

Of course, something could shift. Will the upward ratcheting continue when the Atlantic Multidecadal Oscillation decides to turn around and start its decline? The upward steps would not continue in the North Atlantic, but would the AMO impact the upward steps in other portions of the globe?

The SST anomalies of the East Pacific Ocean, or approximately 33% of the surface area of the global oceans, have risen very little since 1982 based on the linear trend. And between upward shifts, the SST anomalies for the rest of the world (67% of the global ocean surface area) remain relatively flat. Anthropogenic forcings are said to be responsible for most of the rise in global surface temperatures over this period, but the SST anomaly graphs of those two areas prompt a two-part question: Since 1982, what anthropogenic global warming processes would overlook the sea surface temperatures of 33% of the global oceans and have an impact on the other 67% but only in response to the significant El Niño events of 1986/87/88, 1997/98 and 2009/10?

EAST INDIAN-WEST PACIFIC

The SST anomalies in the East Indian and West Pacific rose this month.

I include this dataset to draw attention to what appears to be the upward steps in response to significant El Niño events that are followed by La Niña events.

(5) East Indian-West Pacific (60S-65N, 80E-180)

Monthly Change = -0.044 deg C

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Further information on the upward “step changes” that result from strong El Niño events, refer to my posts from a year ago Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1 and Can El Nino 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 Nina Events Recharge The Heat Released By El Nino 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 Nino & La Nina Events

The animations included in the post La Niña Is Not The Opposite Of El Niño – The Videosfurther 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 December 1981 to July 2011, as it is presented by the NOAA NOMADS website linked at the end of the post.

MONTHLY INDIVIDUAL OCEAN AND HEMISPHERIC SST UPDATES

(6) Northern Hemisphere

Monthly Change = +0.007 deg C

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(7) Southern Hemisphere

Monthly Change = -0.045 deg C

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(8) North Atlantic (0 to 70N, 80W to 0)

Monthly Change = -0.099 deg C

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(9) South Atlantic (0 to 60S, 70W to 20E)

Monthly Change = +0.018 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. It does not appear as though the South Atlantic will return to the level it was at before that surge, and where it had been since the late 1980s. That is, it appears to have made an upward step and continues to rise. Why? Dunno—yet.

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(10) North Pacific (0 to 65N, 100E to 90W)

Monthly Change = +0.027 Deg C

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(11) South Pacific (0 to 60S, 120E to 70W)

Monthly Change = -0.040 deg C

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(12) Indian Ocean (60S to 30N, 20E to 120E)

Monthly Change = -0.102 deg C

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(13) Arctic Ocean (65N to 90N)

Monthly Change = +0.226 deg C

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(14) Southern Ocean (90S-60S)

Monthly Change = +0.050 deg C

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WEEKLY SST ANOMALIES

The weekly NINO3.4 Sea Surface Temperature (SST) Anomalies have dropped considerably and are now approaching the threshold of a La Niña event. Keep in mind, though, that the weekly NINO3.4 SST anomalies are volatile and may not continue to decline. The NINO3.4 SST anomaly based on the week centered on August 3, 2011 is -0.435 deg C.

(15) Weekly NINO3.4 SST Anomalies

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The weekly global SST anomalies are at +0.169 deg C.

(16) Weekly Global

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SOURCE

The Optimally Interpolated Sea Surface Temperature Data (OISST) are available through the NOAA National Operational Model Archive & Distribution System (NOMADS).

http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh