April 2011 Sea Surface Temperature (SST) Anomaly Update

Guest post by Bob Tisdale

WEEKLY NINO3.4 SST ANOMALIES

The weekly NINO3.4 Sea Surface Temperature (SST) Anomalies have just risen above the threshold of a La Niña, and are just barely in ENSO-neutral territory. The NINO3.4 SST anomaly based on the week centered on May 4, 2011 is -0.495 deg C.

(15) Weekly NINO3.4 SST Anomalies

MONTHLY SST ANOMALY MAP

The following is a map of Global OI.v2 SST anomalies for April 2011 downloaded from the NOMADS website. The contour levels are set at 0.5 deg C, and white is set at zero.

April 2011 SST Anomalies Map (Global SST Anomaly = +0.123 deg C)

MONTHLY OVERVIEW

Monthly NINO3.4 SST anomalies are continuing their rise toward ENSO-neutral conditions. The Monthly NINO3.4 SST Anomaly is -0.67 deg C.

The SST anomalies in Northern Hemisphere rose about 0,03 deg C this month, and Southern Hemisphere SST anomalies remained flat. Global SST anomalies rose slightly (+0.012 deg C). The Global SST anomalies are presently at +0.12 deg C.

(1) Global

Monthly Change = +0.012 deg C

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(2) NINO3.4 SST Anomaly

Monthly Change = +0.253 deg C

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THE EAST PACIFIC VERSUS THE REST OF THE WORLD

As noted in the post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World,I have added these two datasets to the monthly updates. Both datasets have been adjusted for the impacts of volcanic aerosols, and both are smoothed with 13-month running-average filters to reduce the seasonal noise. 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, so with ENSO-related SST anomalies varying from La Niña toward ENSO neutral, that trend will also rise slightly each month. But they won’t rise significantly up through the next El Niño.

(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. The “July 2009 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.

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

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EAST INDIAN-WEST PACIFIC

The SST anomalies in the East Indian and West Pacific continued their drop this month.

I’ve added this dataset in an attempt 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 = -0.063 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 April 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 = +0.028 deg C

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(7) Southern Hemisphere

Monthly Change = 0.0 deg C

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(8) North Atlantic (0 to 75N, 78W to 10E)

Monthly Change = +0.056 deg C

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

Monthly Change = -0.129 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 = -0.001 Deg C

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

Monthly Change = +0.055 deg C

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

Monthly Change = -0.045 deg C

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

Monthly Change = +0.015 deg C

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

Monthly Change = +0.086 deg C

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WEEKLY SST ANOMALIES

I shifted the weekly NINO3.4 SST anomalies to the start of the post since they’ve reached ENSO-neutral levels.

The weekly global SST anomalies are at +0.121 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

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15 thoughts on “April 2011 Sea Surface Temperature (SST) Anomaly Update

  1. The weekly NINO3.4 Sea Surface Temperature (SST) Anomalies have just risen above the threshold of a La Niña, and are just barely in ENSO-neutral territory.
    That’s the best you can do? I live in Washington State east of the Cascade Crest. I was hoping “Spring” would arrive before the Summer Solstice.

  2. Meanwhile, Pendleton, Oregon has just confirmed the coldest April in its recorded history. And by no small margin. Here are just a few areas that experienced below normal temps.
    APRIL 2011 DATA AND DEPARTURE FROM NORMAL FOR SELECTED CITIES:
    MAX DEP MIN DEP AVE DEP PCPN DEP
    TEMP NORM TEMP NORM TEMP NORM TOTL NORM
    YAKIMA 59.3 -4.4 30.2 -3.4 44.7 -4.0 0.32 +0.07
    KENNEWICK 60.6 -5.1 39.1 -3.6 49.9 -4.3 0.30 -0.18
    WALLA WALLA 56.4 -5.8 38.4 -4.3 47.4 -5.1 2.09 +0.93
    THE DALLES 58.5 -5.3 39.4 -1.4 48.9 -3.4 1.57 +1.01
    REDMOND 53.4 -6.7 24.2 -3.3 38.8 -5.0 0.28 -0.05
    PENDLETON AIRPORT 55.6 -5.2 34.6 -3.4 45.1 -4.3 0.95 +0.10
    LA GRANDE 50.9 -8.2 32.6 -3.0 41.8 -5.6 2.64 +1.95

  3. Bob:
    What is considered the depth of the “sea surface”?
    What is considered the “turn over” rate for the “surface” versus the complete depth?
    Surely someone must have some estimate of the mixing in the sea.
    In point of fact, does anyone realize that the Japanese have dumped tons of radioactive tracers into the Pacific to help figure this out?
    I’m not joking. Obviously they did not do it intentionally. But if enough measurements are taken soon, we could have a host of info on sea surface mixing in the next few years.
    Max

  4. We out West on at the inputs to the circuit. We are the canaries in the coal mine, so to speak. I must wonder if, during this time we are in (is it merely negative PDO, or, something far grander?), El Nino will be cold and La Nina colder?

  5. Yesterday, NW Calif., it was a brutal sunny day with an icy wind.
    Today was almost non-icy, with the usual frost on the windshield…May 9th.
    Oh, and for a clear day in May it was rather a rather dim sunshine.
    Something is not right.

  6. SteveSadlov says:
    May 9, 2011 at 7:27 pm
    If you mean that the Pacific leads the dance, that’s something to chew on.

  7. John F. Hultquist says:
    May 9, 2011 at 6:57 pm
    That’s the best you can do? I live in Washington State east of the Cascade Crest. I was hoping “Spring” would arrive before the Summer Solstice.
    ===============
    Yeah, spring would be nice. The grass is green and the tulips are blooming, but that’s about it. I think Spring is finally here though.
    Darn that global warming with it’s colder and longer winters.

  8. The most interesting weather/climate is always what we are experiencing at the moment, and the comments above reflect this very well. My weather today is normal May in the UK, 17C, light wind and half cloudy. Not bad for some gardening. However, from the climate (change?) aspect such observations, however accurate and interesting are not very useful.
    I have just downloaded the NOMADS file with monthly SST data, from Nov 1981 to April 2011, and it makes for very interesting reading/interpretation. If any of you have also access to it I recommend applying the cumulative sum transform, which often does a remarkable job of finding the essence of the data. In the case of these SSTs, you will find a remarkable and unmistakable step change occurring at January 1997. Further exploration will reveal that this change is about 0.114C, and that after this date there is no sign of a statistically significant change in SST. The regression slope is very close to zero. Prior to this date there is a significant upward slope of 0.0064C/ Year, probability approx 0.012. A trend fit to the complete data set gives a slope 0.00926, probability < 10E-6, and it's obvious from a simple plot. But be careful about this! The underlying model for the full period considered here is certainly not linear. Why should it be? I've never thought of climate as being in any way linear unless one thinks in terms of fairly short periods or where plotting (with the added discriminatory power of cusums) makes it very obvious that a linear fit can be tentatively proposed. The NOMADS SST set is certainly not linear, imho!

  9. Max Hugoson says: “What is considered the depth of the ‘sea surface’?”
    Sorry for the delay. And I hate to say that it varies, but it does, depending on whether satellites, buoys, buckets, or ship inlets are used for measurement. Wikipedia has a reasonable discussion of it:
    http://en.wikipedia.org/wiki/Sea_surface_temperature
    Then the data suppliers (NOAA and Hadley Centre) make corrections for each type and infill areas where there weren’t observations, assuming those areas are infilled. (The HADSST2 dataset is not infilled.)
    The Reynolds OI.v2 data presented in this post uses a combination of all of them, with satellite observations having the greatest coverage and greatest number of samplings. The fact that it’s satellite based is why it starts in Nov 1981.

  10. Pamela Gray says:
    May 9, 2011 at 6:57 pm
    Hey Pamela, how’s the snow depth holding up out at Mt Hood ? My daughters and I are coming out after the 4th of July for a ski racing camp. ; )

  11. Uh-oh! With both El and La Nino/a ratcheting up the SST in significant regions, more heat will be radiated and lost to space! Disruptive Cooling will accelerate! We’s all dooooomed!

  12. Did anyone notice the NOMADS SST is labeled 2010? It does appear to be the correct analysis, just mislabeled.

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