In ENSO Indices Do Not Represent The Process Of ENSO Or Its Impact On Global Temperature, I eventually divided Global Sea Surface Temperature (SST) anomaly data into two subsets: the East Pacific and the Atlantic-Indian-West Pacific. Both datasets extended from pole to pole. The East Pacific SST anomalies have not risen during the satellite era (that is, since 1982), while the Atlantic-Indian-West Pacific SST anomalies show upward steps in response to the significant El Niño events of 1986/87/88 and 1997/98–and another possible upward step in response to the 2009/10 El Niño. And I illustrated that between those significant El Niño events, the Atlantic-Indian-West Pacific SST anomalies had flat linear trends; that is, the Atlantic-Indian-West Pacific SST anomalies did not rise between those significant El Niño events. I then explained and illustrated how the El Niño-Southern Oscillation (ENSO)-induced rises in the East Indian and West Pacific Oceans were responsible for much of the variability and upward shifts in the Atlantic-Indian-West Pacific, and that the SST anomalies of the East Indian-West Pacific actually dropped between the significant El Niño events. I also showed and discussed how the additional mode of natural variability known as the Atlantic Multidecadal Oscillation (AMO) accounted for the additional upward trend in the North Atlantic.
But the discussions of the North Atlantic and the East Indian-West Pacific datasets left out much of the Atlantic-Indian-West Pacific SST data. Refer to Figure 1. There are some who are skeptical of my posts because my posts contradict their assumptions about the rise in global sea surface temperatures being caused by anthropogenic global warming. And they may feel I was hiding something by not illustrating the SST anomalies for all portions of the global oceans, so…
In this post, I’ve divided the Atlantic-Indian-West Pacific dataset into two subsets that capture all of the SST data in this portion of the global oceans. Refer to Figure 2. The “North Atlantic Plus” data includes the North Atlantic, the Mediterranean, and the Arctic Ocean north of the North Atlantic, using the coordinates of 0-90N, 80W-40E. The South Atlantic-Indian-West Pacific data captures the rest of that portion of the global oceans, from pole to pole. Since I’m using a coordinate-based system (NOAA’s NOMADS website) as the source of data, I divided the area into two additional subsets and presented the weighted average, with the coordinates of 0-90N, 40E-180 representing 27.9% and the coordinates of 90S-0, 80W-180 representing 72.1 %. And to determine the weighting, I used the land mask data that’s part of the NCEP/DOE Reanalysis-2 flux data available through the KNMI Climate Explorer.
A Note About Volcano Adjustments: All datasets in this post have been adjusted for the impacts of the volcanic eruptions of El Chichon and Mount Pinatubo. The method I used was discussed in the post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World, under the heading of Accounting For The Impacts Of Volcanic Eruptions.
THE “NORTH ATLANTIC PLUS” DATA
Figure 3 compares volcano-adjusted North Atlantic (0-70N, 80W-0) SST anomalies to those of the volcano-adjusted “North Atlantic Plus” (0-90N, 80W-40E) subset. They have the same year-to-year variations (correlation coefficient of 0.98) and basically the same linear trend at about 0.222 Deg C/decade.
As illustrated in Figure 4, the linear trends of the volcano-adjusted “North Atlantic Plus” data between the 1986/87/88 and 1997/98 El Niño events and between the 1997/98 and the 2009/10 El Niño events are both positive. There’s no surprise there since the “North Atlantic Plus” data is also governed by the additional mode of variability called the Atlantic Multidecadal Oscillation.
A Note About The Selection Of The Periods Between The ENSO Events: The period between the 1986/87/88 El Niño and the 1997/98 El Niño starts 6-months after the end of the “official” El Niño months of the 1986/87/88 El Niño as presented in the NOAA ONI index and ends 6-months after the “official” start of the 1997/98 El Niño. The same method was applied to determine the period between the 1997/98 and 2009/10 El Niño events. The 6-month lag is based on the response of Atlantic-Indian-West Pacific SST data to the 1997/98 El Niño event. Though there are different response lags for the subsets used in this post, I continue to use the 6-month lag for all to maintain consistency between the graphs of the subsets. The method was discussed in more detail in the post Does The Sea Surface Temperature Record Support The Hypothesis Of Anthropogenic Global Warming?, after its Figure 4.
THE SOUTH ATLANTIC-INDIAN-WEST PACIFIC DATA
Figure 5 includes the volcano-adjusted East Indian-West Pacific SST anomaly dataset that I’ve discussed in numerous posts over the past few years and compares it to the volcano-adjusted South Atlantic-Indian-West Pacific data that’s one of the subsets being discussed in this post. The ENSO-induced variations in the East Indian-West Pacific data dominate the year-to-year and long-term trend of the South Atlantic-Indian-West Pacific data. The correlation coefficient for the two datasets is 0.88, and the East Indian-West Pacific data has a significantly higher linear trend.
As mentioned earlier, the Atlantic-Indian-West Pacific SST anomalies do not rise between the significant El Niño events, but the SST anomalies of the “North Atlantic Plus” dataset do increase between them. This would mean that the South Atlantic-Indian-West Pacific SST anomalies must drop between the significant El Niño events. And, as shown in Figure 6, they do.
As discussed in numerous recent posts, there is no rise in the Sea Surface Temperature of the East Pacific Ocean, about 33% of the global ocean surface area, since 1982. As shown in this post, between the significant El Niño events of 1986/87/88 and 1997/98 and between the significant El Niño events of 1997/98 and 2009/10, Sea Surface Temperatures rise for the “North Atlantic Plus” data (about 13.5% of the global ocean surface area), but that is a function of the Atlantic Multidecadal Oscillation. And the most obvious contradiction to the hypothesis of anthropogenic global warming is the fact that the South Atlantic-Indian-West Pacific SST anomalies, which represents about 53.5 % of the global ocean surface area, actually drop between those significant El Niño events.
There is little to no evidence that anthropogenic greenhouse gases played any role in the rise in Sea Surface Temperature during the satellite era. Researchers might discover this if they were to treat ENSO as a process instead of an index.
The Reynolds OI.v2 SST anomaly data used in this post is available through the NOAA NOMADS website:
The Stratospheric Aerosol Optical Thickness data used for the volcano adjustments is available through the GISS website: