I’ve moved to WordPress: http://bobtisdale.wordpress.com/

Wednesday, October 29, 2008

Atlantic and Pacific SST Dipoles

INTRODUCTION

In the controversial paper “Advancing Decadal-Scale Climate Prediction in the North Atlantic Sector”, Keenlyside et al used the Atlantic SST dipole index as an indicator of Thermohaline Circulation/ Meridional Overturning Circulation (THC/MOC), as opposed to the Atlantic Multidecadal Oscillation (AMO). http://www.usclivar.org/Pubs/2May08Keenlyside.pdf

They define it as: “Atlantic SST dipole index (60–10W, 40–60N minus 50–0W, 40–60S SST area averages), which is constructed to isolate MOC forced SST fluctuations from radiatively forced variations.” The areas of the North and South Atlantic used by Keenlyside are illustrated in Figure 1, as are the areas of the Pacific used in the latter part of this post.
http://i34.tinypic.com/vgiwau.jpg
Figure 1

Keenlyside et al cite the 2005 Latif et al paper “Is the Thermohaline Circulation Changing?” as reference.
http://luv.dkrz.de/publications_2005/pub_291_329.pdf Note that the answer to the title question is no. They explain in the abstract: “Indications of a sustained THC weakening are not seen during the last few decades. Instead a strengthening since the 1980s is observed.” Latif et al further discuss the use of the dipole as, “On these multidecadal timescales, the dipole SST anomaly pattern can thus be used as a fingerprint to detect changes in the MOC (Latif et al., 2004).”

If the intent of the Keenlyside paper was to predict future trends in global temperature, does the use of the Atlantic SST dipole in place of the AMO in the Keenlyside paper seem appropriate? The Keenlyside paper determined the changes in various Northern Hemisphere area temperatures that result from the MOC signal in the North Atlantic, not a small segment of the North Atlantic as illustrated in Figure 1. Or does it make any difference? Is the Atlantic SST Dipole significantly different than the AMO?

Is there a multidecadal pattern in the Pacific dipole that would illustrate the presence of MOC in the Pacific?

Note 1: All graphs in this post include SST anomaly data from January 1854 to September 2008. The data have been smoothed with 37-month running-average filters.

Note 2: Past posts of the North Pacific Residual (NPR) calculated the NPR by subtracting Global SST Anomalies from the SST anomalies of the North Pacific, North of 20N. In this post, Global SST anomalies are subtracted from the SST anomalies of the ENTIRE North Pacific (0-65N). The differences in the NPR are illustrated at the end.

ATLANTIC SST DIPOLE

Figure 2 illustrates the SST anomalies of the two areas chosen by Keenlyside and Latif for use in creating the Atlantic SST Dipole. The North Atlantic data shows the typical decrease in temperature from the late 19th Century to the early 20th, followed by the rebound to the late 1930s. It also illustrates a continuation of the cycle, though dampened, from the 1930s to present, ending in a peak that is approximately the same temperature as the peak in the 1930s. The South Atlantic data show evidence of the Southern Ocean influence.
http://i35.tinypic.com/2vxoz2w.jpg
Figure 2

Subtracting the SST anomalies of the segment of the South Atlantic from the segment of the North Atlantic creates the Atlantic SST Dipole. Refer to Figure 3. It’s similar in appearance to the AMO, but how similar?
http://i33.tinypic.com/2hi5g8z.jpg
Figure 3

Figure 4 is a comparative graph of the Atlantic SST Dipole and the AMO. The AMO data was created by subtracting global SST anomalies from the North Atlantic (70W-10E, 0-75N) SST anomalies. It is clear that the Atlantic SST Dipole has a greater variation. Scaling the AMO by multiplying the data by 2.5, Figure 5, reveals that the signals correlate well from around 1900 to present.
http://i36.tinypic.com/2vnmn3a.jpg
Figure 4
#
http://i35.tinypic.com/vngp3o.jpg
Figure 5

Pacific SST Dipole

To provide as reasonable comparison of Atlantic and Pacific SST Dipoles, I used the same latitudes (40 to 60N and 40 to 60S) for the Pacific SST Dipole data sets. Figure 6 shows the SST anomalies of the North and South Pacific areas used to create it. The North Pacific SSTs dropped significantly from its maximum in the early 1880s to minimum about 1910, then rebounded to a peak of lesser SST in the 1940s. Since the 1940s, the SST anomalies of the area selected in the North Pacific have varied, but never again reached the values in the 1880s. And like the South Atlantic, the SSTs of the area in the South Pacific show the influence of the Southern Ocean.
http://i33.tinypic.com/20ii6gx.jpg
Figure 6

In Figure 7, the Pacific SST Dipole is shown. It was created by subtracting the SST anomalies of the section of the South Pacific from the SST anomalies of the section of the North Pacific. The Pacific SST Dipole does show variability consistent with THC/MOC.
http://i37.tinypic.com/rgyvyt.jpg
Figure 7

A comparison of the Pacific SST Dipole and the North Pacific Residual (Figure 8) shows that the Pacific SST Dipole has variations that are much greater in magnitude. Scaling the North Pacific Residual (Figure 9) illustrates that the two indices do correlate well with one another.
http://i34.tinypic.com/2njx54z.jpg
Figure 8
#
http://i35.tinypic.com/2hx8040.jpg
Figure 9

COMPARISON OF ATLANTIC AND PACIFIC SST DIPOLES

Figure 10 is a comparative graph of the Atlantic and Pacific SST Dipoles. The variations in the Atlantic SST Dipole are clearly greater in magnitude. This indicates a stronger MOC influence in the Atlantic, but does not rule out an MOC signal in the North Pacific. The two indices appear to parallel one another at times, but then diverge at others, amplifying or dampening their impacts on Northern Hemisphere and Global temperatures.
http://i36.tinypic.com/s4umv7.jpg
Figure 10

A NOTE ABOUT THE NORTH PACIFIC RESIDUAL USED IN THIS POST

When I originally plotted the North Pacific Residual, it was for use in a comparison with the Pacific Decadal Oscillation (PDO). Since the PDO is calculated from North Pacific SST anomalies of the area North of 20N, I used the same area for the NPR. This post, as noted earlier, used a North Pacific Residual that was calculated from the SST anomalies of the entire North Pacific. The data sets are different, as illustrated in Figure 11.
http://i37.tinypic.com/2w5rr05.jpg
Figure 11

Figure 12 illustrates the difference between the “cycles” of the Atlantic Multidecadal Oscillation and the North Pacific Residual when the NPR is calculated using SST anomaly data for the area North of 20N. As discussed in earlier posts, the two indices are in synch during some periods and out of synch during others, which would reinforce or partially offset their combined impact on global temperatures.
http://i37.tinypic.com/wb5ouv.jpg
Figure 12

SOURCE

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

Sunday, October 26, 2008

The 1976 Pacific Climate Shift

INTRODUCTION

There are a good number of studies of the 1976 Pacific Climate Shift. Many of them discuss the processes that initiated the shift as modeled in GCMs; others illustrate the resulting effects on climate in the North Pacific and adjoining land surfaces; while still others show its impact on the PDO and ENSO. In “The Evolution of ENSO and Global Atmospheric Temperatures”, Trenberth et al illustrate that even the development of El Nino events changed near that time.
http://www.cgd.ucar.edu/cas/papers/jgr2001b/jgr2.html

Recently, in a post on Tropical SSTs, I noted the upward step change in the Tropical East Pacific SST data that happened in 1976. Refer to Figure 6 here:
http://bobtisdale.blogspot.com/2008/09/tropical-sst-anomalies-revisited-east.html

In this post, I’ll illustrate the step changes, or lack thereof, in various Pacific SST data sets that occurred at 1976. I’ll employ linear trend lines for 30 years before and 30 after 1976 and for 10 years before and after 1976 to help highlight the shifts in SST and the changes in the trends. The trend lines are only being used for emphasis; they are not being used to forecast or hindcast changes outside the periods plotted in the graphs.

As always, there are a few revelations that some might find unusual or unexpected.

BASIN-WIDE PACIFIC OCEAN SHIFT (60S-65N, 120E-100W)

Figures 1 and 2 show the shifts in the Pacific basin SST that occurred at 1976, using the long-term and short-term trend lines as reference. The changes in trends are obvious in the long-term data. The step change is apparent in the short-term data.

#

http://i38.tinypic.com/30sd5hz.jpg
Figure 2

SHIFT IN THE NORTH PACIFIC (0-65N, 100E-90W)

In Figure 3, the change in trend in the North Pacific is also tough to miss. The step change in the North Pacific, Figure 4, is exaggerated compared to the basin-wide Pacific data.
http://i36.tinypic.com/106autk.jpg
Figure 3

#
http://i36.tinypic.com/2mwflar.jpg
Figure 4

SOUTH PACIFIC (0-60S, 145E-70W) APPEARS TO SHIFT EARLIER

If the South Pacific data is divided at 1976, the change in the two long-term trends is not as severe. Refer to Figure 5. The pre-1976 trend in the South Pacific was positive, reducing the visual impact at the change point. A look at the short-term South Pacific data, Figure 6, reveals a negative trend up to 1976.
http://i36.tinypic.com/2aeneya.jpg
Figure 5

#
http://i37.tinypic.com/szze9s.jpg
Figure 6

Take another look at the long-term South Pacific data. A shift appears 8 years before 1976, in 1968. This is emphasized if the trend lines are segmented at 1968. Refer to Figure 7.
http://i34.tinypic.com/2dw6yhf.jpg
Figure 7

THE INFLUENCE OF THE SOUTHERN OCEAN ON THE SOUTH PACIFIC

The Southern Ocean SST anomalies are shown in Figure 8. I’ve marked 1968 on the graph. It, the Southern Ocean, has a major influence on the South Pacific. Through the Humboldt Current (Figure 9), the Antarctic Circumpolar Current (ACC) feeds the South Pacific. Could it take 8 years for the shift in the Southern Ocean and South Pacific to be reflected in the basin wide and North Pacific data sets?
http://i38.tinypic.com/11s30c7.jpg
Figure 8
#
Correction: The end date on Figure 8 originally read 2008. It’s been changed to its correct year, 2006.
http://i34.tinypic.com/30t57o3.jpg
Figure 9

Figure 9 courtesy of Wikipedia. http://en.wikipedia.org/wiki/Image:Humboldt_current.jpg

Note: In Figure 8, I’ve also marked the year that another shift took place in the Southern Ocean SST anomalies, 2000. Seven to eight years later, there was a significant La Nina, and the PDO is said to have shifted to its cold phase. http://www.jpl.nasa.gov/news/news.cfm?release=2008-066 I enjoy coincidences like that. Will the recent shift in the Southern Ocean SSTs drive global temperatures down for a few decades now? To answer yes, one would have to believe the Southern Ocean was in fact one of the ultimate causes of the increase in temperature from the mid-1970s to the early 2000s.

SHIFT IN THE TROPICAL EAST PACIFIC (20S-20N, 90-180W)

Segmenting the Pacific more, Figures 10 and 11 illustrate the significant step changes in the long-term and short-term trends in the Eastern Tropical Pacific.
http://i33.tinypic.com/os5qx4.jpg
Figure 10

#
http://i38.tinypic.com/ei2rko.jpg
Figure 11

SHIFT IN NINO3.4 (5S-5N, 120-170W)

The shifts in the NINO3.4 SST anomalies, Figures 12 and 13, are similar to the Eastern Tropical Pacific. Variations in NINO3.4 SST anomalies are known to cause changes in global climate.
http://i37.tinypic.com/2rwkxug.jpg
Figure 12

#
http://i34.tinypic.com/6o03s5.jpg
Figure 13

SHIFT IN THE EAST PACIFIC (60S-65N, 100-180W)

Consistent with the North Pacific and basin-wide Pacific data, the East Pacific also experienced a substantial upward shift in 1976. Refer to the long-term and short-term East Pacific SST anomaly graphs, Figures 14 and 15.
http://i36.tinypic.com/ndojlv.jpg
Figure 14

#
http://i38.tinypic.com/2dl4p5k.jpg
Figure 15

To counter that there’s a…

DOWNWARD STEP IN THE WEST PACIFIC (60S-65N, 120-180E)

As could be expected, for the short-term data set, Figure 17, the change in the West Pacific SST anomalies opposes the change in the East Pacific. The long-term trends react somewhat differently, Figure 16. I have done a quick search for a shift in the West Pacific data set, looking for one that occurs during the 1960s and 1970s, but none is readily visible. However, note the rise and fall in the West Pacific SSTs during the late 1980s to early 1990s (Figure 16). The surge and retreat appears to be a response to the multiyear El Nino preceding it. Starting in 1998, it is followed by another rise to a plateau, a result of the 97/98 El Nino, which has taken longer to subside.
http://i33.tinypic.com/2n6rrk.jpg
Figure 16

#
http://i35.tinypic.com/2pshqgy.jpg
Figure 17

The decrease in the West Pacific anomalies at 1976 (while the temperature rises in the East Pacific) is consistent with the relationship between the Tropical East and Tropical West Pacific, Figure 18. In the Tropical Pacific SST anomaly data, the variations in the West SST anomalies oppose the major variations in the East SST anomalies.
http://i35.tinypic.com/166jack.jpg
Figure 18

SOURCE

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

Thursday, October 23, 2008

Comparison of Versions 2 and 3 of Extended Reconstructed Sea Surface Temperature

The third version of the Extended Reconstructed Sea Surface Temperature (ERSST.v3) is available in ASCII format in a number of data sets segmented by latitude. The data spans the period of January 1880 to April 2008. It has not been updated since then. The selection page for the data sets (land only, ocean only, and land-ocean combined, all at various latitude bands) is here. ftp://eclipse.ncdc.noaa.gov/pub/ersst/pdo Don't let the PDO suffix worry you. There's lots more there. The discussion page:
http://www.ncdc.noaa.gov/oa/climate/research/sst/ersstv3.php

But how does the ERSST.v3 data compare to the version available from the NOMADS system (ERSST.v2), the data I’ve been using for the posts on SST? I’ve already discussed the substantial differences in the newer versions as they pertain to the Arctic Ocean and Southern Ocean data sets. The additional resolution in those two high-latitude areas is necessary to the understanding of oceanic climate, especially the Southern Ocean as it is the hub between the three major oceans and of Thermohaline Circulation.
http://bobtisdale.blogspot.com/2008/10/ersstv3-version-of-arctic-ocean-sst.html
http://bobtisdale.blogspot.com/2008/09/ersstv3-version-of-southern-ocean-sst.html

The Arctic and Southern Oceans, presented again in Figures 7 and 12, were the two areas with the greatest changes between versions. The changes to the Southern Hemisphere data are also greater than that of the Northern Hemisphere. In the following 13 graphs, I won’t provide any commentary; I’ll let the differences speak for themselves. The various latitude bands are as provided by the NCDC in the listing of ERSST.v3 data sets.

Latitude Band = 0 to 30N
http://i33.tinypic.com/2hs0w2s.jpg
Figure 1
#

Latitude Band = 0 to 90N
http://i37.tinypic.com/jufude.jpg
Figure 2
#

Latitude Band = 20 to 90N
http://i34.tinypic.com/2u77tqw.jpg
Figure 3
#

Latitude Band = 20S to 20N
http://i36.tinypic.com/awufk9.jpg
Figure 4
#

Latitude Band = 30 to 60N
http://i34.tinypic.com/eprvhz.jpg
Figure 5
#

Latitude Band = 0 to 30S
http://i33.tinypic.com/24buej9.jpg
Figure 6
#

Latitude Band = 60 to 90N
http://i35.tinypic.com/2wfqpua.jpg
Figure 7
#

Latitude Band = 30 to 60S
http://i36.tinypic.com/2qdrk2r.jpg
Figure 8
#

Latitude Band = 60S to 60N
http://i33.tinypic.com/33vlumw.jpg
Figure 9
#

Latitude Band = 0 to 90S
http://i33.tinypic.com/711dvn.jpg
Figure 10
#

Latitude Band = 20 to 90S
http://i35.tinypic.com/124j9uc.jpg
Figure 11
#

Latitude Band = 60 to 90S
http://i35.tinypic.com/2005rb7.jpg
Figure 12
#

Latitude Band = 90S to 90N
http://i33.tinypic.com/1zv3220.jpg
Figure 13
#

CLOSING

As soon as I find a way to easily download gridded time series data for the ERSST.v3 version, I will use it in my SST posts. Until that time, what’s available through NOMADS will suffice.

SOURCES

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

The source of the more recent version of the Smith and Reynolds Extended Reconstructed SST (ERSST.v3) is listed at the opening of this post.

Saturday, October 18, 2008

Does The Storminess Record of the Armagh Observatory Show A Correlation Between Gales And Global Temperature?

No.

The Armagh Observatory in Northern Ireland has monitored and recorded the number of storms with gale winds since 1796, with a short period in the early 1800s (1825 to 1833) during which data is not available or incomplete. The record is available here:
http://climate.arm.ac.uk/publications/The_Storminess_Record_from_Armagh_Observatory_Dr4.pdf
Appendix 4 starts on page 80 and lists the “Seasonal Distribution of Gales from Weather Diary at Armagh Observatory 1796-2000”. The following four graphs illustrate the seasonal gales per year from 1796 to 2000. All four graphs show an increase in storms from the early 20th Century to the mid to late 20th Century. But then the frequency of gales decreases as global temperatures continues to rise.

http://i36.tinypic.com/14kayd4.jpg
Winter Gales


http://i33.tinypic.com/sdffk5.jpg
Spring Gales


http://i38.tinypic.com/33azdb6.jpg
Summer Gales


http://i37.tinypic.com/2unwyfo.jpg
Fall Gales

The seasonal data is totaled in the next graph, which shows the annual gales from 1796 to 2000. The two anomalous peak years are 1950 and 1982. The trough between them bottoms out in the early 1970s. I’ve also smoothed the data with a 10-year running-average filter, in case the underlying trend wasn’t apparent to some.
http://i36.tinypic.com/2me71cg.jpg
Annual Gales

SOURCE

The Armagh Observatory website address is:
http://www.arm.ac.uk/

Wednesday, October 15, 2008

Atlantic, Indian, and Pacific Ocean SSTs Segmented By Longitude

INTRODUCTION

In a prior post I divided global SST anomaly data into quadrants.
http://bobtisdale.blogspot.com/2008/09/sst-anomalies-by-global-quadrants.html

In this post, I first lopped off the high latitudes to eliminate the Arctic and Southern Oceans. Then I divided the globe using longitudes to isolate major portions of individual oceans. Refer to Figure 1. The shapes of the continents and oceans prevent this from being a perfect division, but it is much simpler than downloading multiple data sets and adjusting for area. It also leaves two areas with mixes of two oceanic data sets and requires that I include a portion of the Indian Ocean south of Australia with the Pacific data sets.


http://i33.tinypic.com/24bn5g2.jpg
Figure 1

In this post, all long-term graphs are made up of monthly data from January 1854 to September 2008 that have been smoothed with 37-month running-average filters. The short-term graphs are of raw monthly data from January 1978 to September 2008.

There are a few eye-opening effects that aren’t revealed when the oceans are divided by hemispheres. Other known behaviors are reinforced.

PACIFIC OCEAN

The graph of the long-term Pacific Ocean SST anomaly data (Figure 2) is very similar in appearance to the global SST anomalies. They’re compared in Figure 3. This, of course, is logical since the Pacific Ocean represents the largest portion of the global oceans. A noteworthy difference in my eyes is the exaggeration of the drop in Pacific Ocean SST in the late 19th century. There are other minor divergences. When, in the future, I isolate the Pacific more thoroughly, I will create a residual data set of the Pacific so we can look at the differences between it and global SST anomalies.
http://i35.tinypic.com/mc91r9.jpg
Figure 2




http://i34.tinypic.com/2enxjrq.jpg
Figure 3

Figure 4 is a graph of the short-term SST data set for the Pacific Ocean. SST anomalies there have been dropping rapidly since 2005. They’re nearing pre-97/98 El Nino ranges.
http://i38.tinypic.com/2my3dzb.jpg
Figure 4

In Figure 5, I’ve separated the Pacific Ocean at the date line, isolating East and West Pacific data. The 37-month smoothing highlights the opposing cycles in SST. To me, this indicates the transfer of heat from east to west and back again during and between ENSO events. What also stands out for me is the drastic step in the West Pacific data in recent times.
http://i38.tinypic.com/1zfn8nm.jpg
Figure 5



The short-term data for the East and West Pacific (Figure 6) continues to illustrate the opposing cycles. It also shows the step change in the West Pacific SST anomalies following the 1997/98 El Nino.


http://i34.tinypic.com/5tx6qg.jpg
Figure 6

I’ve isolated the West Pacific data in Figure 7 and added pre-1997 and post-1997 linear trend lines. There appears to have been a significant upward step in West Pacific SST as a result of the 1997/98 El Nino. Unless there was also a coincidental change in coastal upwelling at the same time, the graph further illustrates the long-term impacts of that ENSO event. Are the long-term step changes of smaller ENSO events simply hidden by the noise of Rossby waves and subsequent ENSO variations?
http://i34.tinypic.com/10pr9cm.jpg
Figure 7

ATLANTIC OCEAN

Like the Pacific Ocean, the long-term graph of Atlantic Ocean SST anomalies bears a strong similarity to global SST anomalies. Refer to Figures 8 and 9. The greatest divergence in the Atlantic Ocean data set occurs before 1918, when Atlantic SSTs dropped much lower than Global SSTs.
http://i36.tinypic.com/ioq7p0.jpg
Figure 8




http://i37.tinypic.com/14obxva.jpg
Figure 9

Figure 10 illustrates the short-term SST anomalies for the Atlantic Ocean. Like many other data sets, it displays an upward step change as a result of the 1997/98 El Nino.
http://i34.tinypic.com/11kfuop.jpg
Figure 10

This is emphasized when pre-1997 and post-1997 linear trend lines are added to the plot of the short-term Atlantic Ocean SST anomalies. Refer to Figure 11.

Also note the anomalous spike in Atlantic SST occurring late in 2003. As will be shown later in this post, there was no El Nino at that time.
http://i35.tinypic.com/9fmneo.jpg
Figure 11

INDIAN OCEAN

The long-term SST anomaly graph of the Indian Ocean (Figure 12) is dominated by rise in SST from 1929 to 1942. Part of the drop from 1942 to 1948 can be attributed to the errors in the transition between SST sampling methods, but the rise should remain unaffected as it occurred prior to the time of the known error, 1945. Figure 13 provides a comparison of Indian Ocean and Global SST anomalies.
http://i37.tinypic.com/6gy13m.jpg
Figure 12




http://i36.tinypic.com/izbal5.jpg
Figure 13

Figure 14 illustrates the short-term SST anomaly data for the Indian Ocean. Note how there appears to be two major shifts in SSTs, the first occurring as an aftereffect of the 1986/87/88 El Nino and the second as result of the 1997/98 El Nino. SSTs rise sharply as a result of the El Ninos, then gradually decrease until the next major El Nino. Though I’ve seen the effect before, for some reason, I haven’t highlighted it.
http://i33.tinypic.com/1z9pxj.jpg
Figure 14

The shifts are further emphasized by adding the linear trend lines for the periods from January 1978 to December 1985, and from of January 1988 to December 1996, and from January 1998 to September 2008. Refer to Figure 15. This appears to clearly indicate two things: As discussed, there are regular shifts in the SST anomalies of the Indian Ocean that can be attributed to major El Nino events. Second, there is a significant time period required by the Indian Ocean to dissipate the heat added by major El Nino events. It took almost a decade in the first example, between the 1986/87/88 and the 1997/98 El Nino events. The Indian Ocean is still losing heat from the 1997/98 El Nino.

http://i36.tinypic.com/2a9ec0p.jpg
Figure 15
(Note that I’ve done a quick correction to the Title of Figure 15. The update was posted on 11/3/08, which is after blogspot revised the sizing of uploaded pictures.)

Note how the 1982/83 El Nino, which was nearly the same magnitude as the 1997/98 El Nino, did not cause the same phenomenon. As is well documented, the effects of the 1982/83 El Nino were suppressed by the 1982 El Chichon eruption (and two other explosive volcanic eruptions that same year).

THE MIXED DATA SETS

The SST anomalies for the mixed Atlantic-Pacific and the Indian-Pacific data sets are compared to the SST anomalies for the adjoining ocean data sets in Figures 16 and 17. The Southeastern Pacific is the likely cause of the wide variations in mixed Atlantic-Pacific data. There are minor differences in the Indian Ocean and the mixed Indian-Pacific data.

http://i36.tinypic.com/mrwljn.jpg
Figure 16


http://i35.tinypic.com/rap6h2.jpg
Figure 17

RETURNING TO THE SHORT-TERM ATLANTIC OCEAN DATA

I pointed out the 2003 spike in the short-term Atlantic Ocean SST anomaly data earlier in this post. Figure 18 compares Atlantic SST anomalies with scaled Nino3.4 SST anomalies. The scaling factor used for the NINO3.4 data is 0.1. The 2003 spike appears anomalous.
http://i37.tinypic.com/71lm9s.jpg
Figure 18

In this post I’ve shown the long-term effects of major El Nino events on the Indian Ocean. Could the 2003 spike in the Atlantic Ocean data illustrate a long-lasting Rossby wave? There is a study (“Decade-scale trans-Pacific propagation and warming effects of an El NiƱo anomaly” by Jacobs et al, 1994) that discusses the effects of a Rossby wave that existed for a dozen years. http://www.nature.com/nature/journal/v370/n6488/abs/370360a0.html

Is this spike in 2003 a confirmation of long-term Rossby waves? In Figure 19, I’ve shifted the scaled NINO3.4 SST anomaly data 6 years and compared it to the Atlantic data. The eye tends to look for correlations, but there could be a relationship there and over the entire term of the data.
http://i34.tinypic.com/2ah6qys.jpg
Figure 19

CLOSING

In a future post, I will further investigate the response of the Indian Ocean to El Nino events, especially the long-term decay in temperature. How far back in time is that cause and effect visible? Does it start as part of the Great Pacific Climate Shift of 1976, or does it go back farther?

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

Donations

Tips are now being accepted.

Comment Policy, SST Posts, and Notes

Comments that are political in nature or that have nothing to do with the post will be deleted.
####
The Smith and Reynolds SST Posts DOES NOT LIST ALL SST POSTS. I stopped using ERSST.v2 data for SST when NOAA deleted it from NOMADS early in 2009.

Please use the search feature in the upper left-hand corner of the page for posts on specific subjects.
####
NOTE: I’ve discovered that some of the links to older posts provide blank pages. While it’s possible to access that post by scrolling through the history, that’s time consuming. There’s a quick fix for the problem, so if you run into an absent post, please advise me. Thanks.
####
If you use the graphs, please cite or link to the address of the blog post or this website.