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.

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/

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 Niño 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