August 2011 Sea Surface Temperature (SST) Anomaly Update

MONTHLY SST ANOMALY MAP

The following is a Global map of Reynolds OI.v2 SST anomalies for August 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. It appears to have peaked in August. I will be posting about it shortly. I’m just waiting for a specific long-term dataset to be updated at the KNMI Climate Explorer.

August 2011 SST Anomalies Map (Global SST Anomaly = +0.169 deg C)

MONTHLY OVERVIEW

Monthly NINO3.4 SST anomalies have dropped 0.405 deg C from July to August. They are now at at -0.524 deg C, which is below the threshold of a La Niña.

The SST anomalies dropped in only two ocean basins this month: the South Atlantic and South Pacific. They were responsible for the minor drop in Southern Hemisphere SST anomalies. That decline was more than countered by the rise in Northern Hemisphere SST anomalies, so Global SST anomalies rose +0.023 deg C. The Global SST anomalies are presently at +0.169 deg C.

(1) Global

Monthly Change = +0.021 deg C

####################################

(2) NINO3.4 SST Anomaly

Monthly Change = -0.405 deg C

####################################

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)

####################################

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)

####################################

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 during the months of 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 = +0.050 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 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 November 1981 to August 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 = +0.060 deg C

####################################

(7) Southern Hemisphere

Monthly Change = -0.004 deg C

####################################

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

Monthly Change = +0.099 deg C

####################################

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

Monthly Change = -0.114 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.

####################################

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

Monthly Change = 0.0 Deg C

####################################

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

Monthly Change = -0.012 deg C

####################################

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

Monthly Change = +0.117 deg C

####################################

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

Monthly Change = +0.235 deg C

####################################

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

Monthly Change = +0.004 deg C

####################################

WEEKLY SST ANOMALIES

The weekly NINO3.4 Sea Surface Temperature (SST) Anomalies rose slightly over the past week but remained below the threshold of a La Niña event. The NINO3.4 SST anomaly based on the week centered on August 3, 2011 is -0.562 deg C.

(15) Weekly NINO3.4 SST Anomalies

####################################

The weekly global SST anomalies are at +0.220 deg C.

(16) Weekly Global

####################################

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

Advertisements

About Bob Tisdale

Research interest: the long-term aftereffects of El Niño and La Nina events on global sea surface temperature and ocean heat content. Author of the ebook Who Turned on the Heat? and regular contributor at WattsUpWithThat.
This entry was posted in SST Update. Bookmark the permalink.

7 Responses to August 2011 Sea Surface Temperature (SST) Anomaly Update

  1. Espen says:

    The step up after the 2009/2010 El Niño in your figure 4 could easily turn into a step down if we’re heading into another strong La Niña now – couldn’t it?

  2. Bob Tisdale says:

    Espen: Sorry for the delay getting back to you. It’s tough to say what the ROW data will do in response to a back-to-back La Niña:

    But I don’t believe it would turn into a step down while the North Atlantic (AMO) is still rising.

  3. Juraj V. says:

    HadSST2 and ERSST based AMO index is flat or just peaking, depends on which ocean area is considered. But the actual North Atlantic SST record seems to have peaked around 2006 and is on the downward track since.

    Blue – N. Atlantic SST 0-70N/28-360E, red – N. Atlantic OHC
    Curious, what is the mechanism that NA ceased to rise after El NIno events as it did before.

  4. Bob Tisdale says:

    Juraj V. : the units for one of the datasets listed on your graph…

    …are 10^22 Joules so one of the datasets is OHC. Also, the coordinates you’ve listed 0-70N, 28E-360E includes the North Atlantic but it also includes the North Pacific and the North Indian. It’s basically the Northern Hemisphere south of 70N, excluding the Northeast Atlantic, the Mediterranean and a small portion of the Eastern Tropical Atlantic.

  5. Juraj V. says:

    This was a typo, I used 280-360E when generating the graph. Yes there is OHC and SST overlaid in one graph.

  6. Bob Tisdale says:

    Juraj V. says: “This was a typo, I used 280-360E when generating the graph.”

    Thanks for the clarification. It was tough to make out on the graph.

  7. Pingback: Broome and the tropics…weather | pindanpost

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s