>SSTs at the Centers of Ocean Gyres and A Predictor (?) of North Atlantic SST

>INTRODUCTION

Figure 1 is a simplistic illustration of ocean gyres. In the following, I’ve illustrated SST anomalies at the “centers” of all five. It appears that SSTs at the center of the North Atlantic gyre lead SSTs for the majority of the North Atlantic by almost three years. Could SSTs at the center of the North Atlantic gyre be used to predict the temperature of the North Atlantic and its impacts on European and North American climate?

http://i35.tinypic.com/20tkojo.jpg
Figure 1

SSTs AT THE CENTERS OF GYRES

Figure 2 depicts the locations of the data sets used in the following. I did NOT perform a detailed analysis of ocean currents to pick the spots; I eyeballed centers based on the representations of the gyres in Figure 1. I’m a blogger, not a climatologist; that’s my excuse. The following are the coordinates used:
North Pacific Gyre = 15 to 25N, 150 to 160W
South Pacific Gyre = 45 to 55S, 135 to 145W
North Atlantic Gyre = 30 to 40N, 35 to 45W
South Atlantic Gyre = 35 to 45S, 15 to 25W
Indian Ocean Gyre = 32 to 42S, 80 to 90E
http://i37.tinypic.com/kd90du.jpg
Figure 2

All five data sets are shown in Figure 3, which clearly illustrates that there are no obvious relationships between the SST anomalies of the group as a whole.
http://i35.tinypic.com/29m1t21.jpg
Figure 3

The SST anomalies of the North and South Pacific gyres are illustrated in Figure 4. The mutual influences are obvious, as are the greater variations in the North Pacific signal. Note that both filtered signals are decreasing before, during, and after the 97/98 El Nino.
http://i33.tinypic.com/r8e1eg.jpg
Figure 4

In Figure 5, the SST anomalies for the North and South Atlantic gyres are presented. At first glance, it almost appears as if the South Atlantic, with additional underlying oscillations, lags the North by around 40 years. However, a closer inspection reveals that the South Atlantic has an SST anomaly rise from the 1960s to the early 1980s, then a drop from 1990 to present, reminiscent of the Southern Ocean SST anomaly curve. This is later compared in Figure 8.
http://i35.tinypic.com/351tksi.jpg
Figure 5

The SST anomalies at the centers Northern Hemisphere gyres are shown in Figure 6. Recall that these data sets may not be representative of the oceans or their climatic effects. They are not from scientifically selected areas and may or may not be at the centers of the gyres based on ocean currents. Regardless, the Atlantic signal has a higher amplitude than the Pacific, with less noise.
http://i34.tinypic.com/20ftd90.jpg
Figure 6

Figure 7 shows the SST anomalies at the centers of the three Southern Hemisphere gyres. The South Pacific curve is much flatter than the two others, while the shapes of the South Atlantic and South Indian Ocean data sets agree with the overall shape of the Southern Ocean SST anomaly curve, Figure 8.
http://i34.tinypic.com/2mniqt5.jpg
Figure 7

http://i38.tinypic.com/2aiz3n.jpg
Figure 8

A PREDICTER (?) OF NORTH ATLANTIC SST

Of the SST anomaly data sets illustrated, the North Atlantic gyre signal has the strongest oscillation, with the least noise. In an effort to determine how widespread that THC/MOC signal is, I used the original coordinates of the center of the North Atlantic gyre as a starting point, then expanded the area in 10 degree steps of latitude and longitude. Refer to Figure 9.
http://i35.tinypic.com/33ej7kk.jpg
Figure 9

As could be expected, the smaller area had the greatest variation. Refer to Figure 10. What was unexpected was how little the variance was between the smallest and largest areas. The final point that stood out was the time lag between the smallest and the largest areas. Could this lag be present in a comparison of the center of the North Atlantic gyre and the North Atlantic SST anomalies?
http://i37.tinypic.com/2l7upc.jpg
Figure 10

Figure 11 illustrates the two areas bordered by the Black and the Bronze rectangles used in the following comparison. Disregard the other intermediate areas depicted; their curves simply cluttered the graph.
http://i38.tinypic.com/157ghs2.jpg
Figure 11

Figure 12 shows the SST anomalies for the center of the North Atlantic gyre (30 to 40N and 35 to 45W) and the North Atlantic (0 to 65N and 0 to 80W) from 1854 to 2008, smoothed with an 85-month filter. Note how the major changes in trend of the curve for the Center of the North Atlantic gyre occur about 3 years before the curve for the majority of the North Atlantic.
http://i35.tinypic.com/o6a0bk.jpg
Figure 12

Amazingly, when the time span is shortened to the last 30 years, and when one data set is shifted 35 months, the two curves correlate very well. Refer to Figure 13, in which the data has not been smoothed. This seems to indicate that the SST anomaly at the center of the North Atlantic gyre could be used to predict trends in North Atlantic SST.
http://i34.tinypic.com/oatb7p.jpg
Figure 13

Documenting the THC/MOC curve in the North Pacific and this discovery have made all the work that went into creating this series on the Smith and Reynolds SST data worthwhile.

SOURCE

Sea Surface Temperature Data is Smith and Reynolds Extended Reconstructed SST (ERSST.v2) available through the NOAA National Operational Model Archive & Distribution System (NOMADS).
http://nomads.ncdc.noaa.gov/#climatencdc

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.
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21 Responses to >SSTs at the Centers of Ocean Gyres and A Predictor (?) of North Atlantic SST

  1. Pascvaks says:

    FWIW –
    Used the Wikipedia article for the “N.Pacific Garbage Patch” to insert coordinates 35N-42N and 155W-135W for the N.Pac. Gyre Center location and came up with this graph of temps over time, 1981-2012; thought you might find it interesting. (Shame we don’t have more garbage in the other gyres to mark their centers–Sarc!;-) –
    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=monoiv2.ctl&ptype=ts&var=ssta&level=1&op1=3tave&op2=none&month=nov&year=1981&fmonth=may&fyear=2012&lat0=35&lat1=42&lon0=-155&lon1=-135&plotsize=800×600&title=NPacGarbagePatch+%2835Nto42N%2C155Wto135W%2Cw3ptTimeMean%29&dir=

    Still swimming;-)

  2. Bob Tisdale says:

    Pascvaks: Thanks. Did it shifted up in response to the 1988/89 La Nina, but not the 1998/99/00/01 La Nina?

  3. Pascvaks says:

    Bob-
    Not sure that this will be of any real value re your question.
    First graph below shows a modified Nino 3.4 that corresponds to the width of the Garbage Patch Gyre directly North of it. Second graph shows the Garbage Patch. If I’m reading them correctly, the Garbage Patch does seem to ‘precede’ the modified Nino3.4 graph in time, but not precisely. Hope this offers something of value. (You were very kind to ask what you did, I did go looking for something, but if it’s a “rusty time can” please forgive my ignorance;-)

    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=oiv2.ctl&ptype=ts&var=ssta&level=1&op1=40tave&op2=none&day=03&month=jan&year=1990&fday=06&fmonth=jun&fyear=2012&lat0=-5&lat1=5&lon0=-155&lon1=-135&plotsize=800×600&title=Nino3.4x%285S-5N%2C155W-135W%2C40ptTimeMean%29&dir=

    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=oiv2.ctl&ptype=ts&var=ssta&level=1&op1=40tave&op2=none&day=03&month=jan&year=1990&fday=06&fmonth=jun&fyear=2012&lat0=35&lat1=42&lon0=-155&lon1=-135&plotsize=800×600&title=Garbage+Patch%2835N-42N%2C155W-135W%2C40ptTimeMean%29&dir=

  4. Pascvaks says:

    Re: “…but not precisely.”
    What I was trying to say but didn’t: the ‘Grye Center Graph’ temp changes do seem to ‘predict’ the direction of the reduced area Nino 3.4 graph, up is up, down is down, but the strength of increase/decrease is ‘off’. Hope this matter makes more sense to you, I’m at a loss to ‘guess’ what it’s saying.

  5. Bob Tisdale says:

    Thanks, Pascvaks. Interesting. I’ll have to examine that.

    Regards

  6. Pascvaks says:

    Bob-
    FWIW I did a new location for the N.Atl. Sargasso Gyre Center at 25N-30N and 60W-50W and came up with this graph for your review, haven’t tried to match/crosscheck with anything else in the N.Atl. yet. Best;-)

    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=oiv2.ctl&ptype=ts&var=ssta&level=1&op1=40tave&op2=none&day=03&month=jan&year=1990&fday=06&fmonth=jun&fyear=2012&lat0=25&lat1=30&lon0=-60&lon1=-50&plotsize=800×600&title=SargassoGyre%2825N-30N%2C60W-50W%2C40ptTimeMean%29&dir=

  7. Bob Tisdale says:

    Thanks again, Pascvaks.

    You appear to be enjoying your new-found toy.

  8. Pascvaks says:

    Bob-
    Ref your last, “Life’s a Beach!”;-)

  9. Bob Tisdale says:

    Once again, thanks, Pascvaks.

  10. Pascvaks says:

    Bob-
    One more set of graphs:-)
    The Sargasso –
    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=monoiv2.ctl&ptype=ts&var=ssta&level=1&op1=14tave&op2=none&month=nov&year=1981&fmonth=may&fyear=2012&lat0=25&lat1=30&lon0=-60&lon1=-50&plotsize=800×600&title=Sargasso%2825-30N%2C+60-50W%2C+14pt+MeanTime%29&dir=

    The North Atlantic –
    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=monoiv2.ctl&ptype=ts&var=ssta&level=1&op1=14tave&op2=none&month=nov&year=1981&fmonth=may&fyear=2012&lat0=10&lat1=60&lon0=-60&lon1=-20&plotsize=800×600&title=N.Atl.+%2810-60N%2C+60-20W%2C+14pt+MeanTime%29&dir=

    “Guesstimation Time” Comments – Eyeball comparison of the two graphs above appears to ‘say’ that the Sargasso Gyre Center is ‘predictive’ of the North Atlantic Ocean’s temperature (note: I reduced the size of the N.Atl. to a smaller plot than normal). Taking a ‘great’ leap — it may very well be that the other Gryes are also ‘predicitve’ of their ocean’s warming and cooling, and Nino3.4? 😉

    Anyway, you’ve been very patient and kind, and I’m going to try to revert back to observation mode. I’m guessing that Gryes are like Urban Heat Islands (or more properly, they are like Gyres), and that there are some minor gryes (ie the Kuroshio, etc.) that play a little havoc with the Big Gyres.

    Again, thank you for putting up with me Bob, you’re very kind.

  11. Pascvaks says:

    Bob-
    Back again like a bad penny;-)
    FWIW I just finished reading your latest at
    https://bobtisdale.wordpress.com/2012/06/29/on-sallenger-et-al-2012-hotspot-of-accelerated-sea-level-rise-on-the-atlantic-coast-of-north-america/
    Afterwords I wanted to compare your NAtl Fig 11 graph to the Sargasso graph that I made above and came here to check it. Your latest (Fig 11 in Article at link above) –

    My Sargasso graph on this page above, (here’s link again to save time) –
    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=monoiv2.ctl&ptype=ts&var=ssta&level=1&op1=40tave&op2=none&month=nov&year=1981&fmonth=may&fyear=2012&lat0=25&lat1=30&lon0=-60&lon1=-50&plotsize=800×600&title=N.Atl.SargassoGryeCenter%2825N-30N%2C60W-50W%2C40ptTimeMean%29&dir=
    Nothing ‘predictive’ in my Sargasso Graph of your latest graph at Wilmington (shucks;-( BUT there does seem to be something ‘predictive’ in your Wilmington Chart for the Sargasso Graph I made. Will likely be nothing new to you, but… maybe? Like I said, FWIW. Have a COOL Sunday, we’re back up to 106;-)

  12. Pascvaks says:

    Ref that 106, that’s temp. Didn’t think to include humidity aka “Heat Index”;-)

  13. Bob Tisdale says:

    Pascvaks: Thanks for all your efforts with the use of the gyre centers as predictors of basin SST.

    Good luck staying cool. Newfoundland is really nice this time of year. And the time zone being 1/2 hour different than elsewhere is interesting.

    I hope you used your leap second wisely.

  14. Pascvaks says:

    Bob –
    😉 Now it seems the wabbit has scurried off into a hole named “Wilmington”, something about sea level there, and Sargasso Gyre Temps nearby. He’s a Bugsy Little Hopper! Always thought sea levels came after ocean surface temps. Why would it be the other way around in Wilmington, dat is de question.

    Hope you’re enjoying all that nice neat cool weather in the new found land, stay away from Fundy, I hear the tide there is ‘abnormal’ or something. Best! 😉

    PS: There’s a thought, “Fundy” long term sea level changes, I wonder….

  15. Pascvaks says:

    Bob- (Don’t let me distract you, put this off till later –if ever– Have Fun In New FUNland above all else;-)

    eWent to ‘Fundy’ but it wasn’t any fun;-) and came back and read your latest
    https://bobtisdale.wordpress.com/2012/07/02/the-curious-northern-hemisphere-sea-surface-temperature-anomaly-patterns/
    And took your Fig 5 (Prelim NW NAtl SSTA graph) and smoothed it a little http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=monoiv2.ctl&ptype=ts&var=ssta&level=1&op1=40tave&op2=none&month=nov&year=1981&fmonth=jun&fyear=2012&lat0=45&lat1=70&lon0=-65&lon1=-25&plotsize=800×600&title=N.W.%20NAtl.%2825N-30N%2C60W-50W%2C40ptTimeMean%29&dir=
    and compared it to the Sargasso chart I made above that I updated to include June 2012
    http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?ctlfile=monoiv2.ctl&ptype=ts&var=ssta&level=1&op1=40tave&op2=none&month=nov&year=1981&fmonth=jun&fyear=2012&lat0=25&lat1=30&lon0=-60&lon1=-50&plotsize=800×600&title=N.Atl.SargassoGryeCenter%2825N-30N%2C60W-50W%2C40ptTimeMean%29&dir=
    slap my hands if I’m wrong (and you have the time), but the Sargasso Chart seems to presage the NW NAtl chart and the latest rise in the NW NAtl is not going to be long in lasting, followed by a dive, and then followed by another up per the Sargasso?

  16. Bob Tisdale says:

    Pascvaks says, “Do you, hopefully, ‘a gyre’?”

    You know me, I like to do my wiggle matching on the same graph.

    Regards.

  17. Pascvaks says:

    Bob-
    I read your response so fast I thought you said –
    “You know me, I like to do my wiggle watching on the same graph.”
    and I thought, the same graph? Hummm, he must be having a real fine time in the New Fun Land. Then I reread it.
    😉

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