2014/15 El Niño – Part 3 – Early Evolution – Comparison with 1982/83 & 1997/98 El Niño Events

Comparisons are still being made of the 1997/98 El Niño with the El Niño forming this year. So I thought we should compare the weekly sea surface temperature anomalies for this year, in two NINO regions, with those during 1997 for the 1997/98 El Niño and 1982 for the 1982/83 El Niño. The 1982/83 and 1997/98 El Niño events were the two strongest single-season events of the late 20^th Century. (The 1986/87/88 El Niño wasn’t as strong as the 1982/83 El Niño in terms of peak sea surface temperature anomalies, but the 1986/87/88 event remained an El Niño for more than one year, so it was likely comparable to the 1982/83 El Niño if duration is taken into account.)

First, the NINO3.4 region, see Figure 1. The NINO3.4 region is bordered by the coordinates of 5S-5N, 170W-120W. See the illustration here for the location.  It captures the sea surface temperature anomalies of the east-central equatorial Pacific. Sea surface temperature anomalies of the NINO3.4 region are a commonly used index for the strength, timing and duration of El Niño and La Niña events.   And as you can see, the weekly NINO3.4 sea surface temperature anomalies still have not reached the +0.5 deg C threshold of El Niño conditions. It’s still a little early. They are presently at +0.31 Deg C compared to the reference years of 1971-2000.

Figure 1

Sea surface temperature anomalies in the NINO3.4 region are evolving about the same as they did for the 1982/83 and 1997/98 El Niños.

– HOWEVER –

Sea surface temperature anomalies of the NINO3.4 region really don’t do justice to the 1997/98 El Niño. That El Niño was freakish in how quickly it evolved in the eastern (not central) equatorial Pacific and how warm the sea surface temperatures eventually grew there. We can use the sea surface temperature anomalies of the NINO1+2 region to illustrate this. See Figure 2. The NINO1+2 region is bordered by the coordinates of 10S-0, 90W-80W. It’s just west  east and south of the Galapagos Islands.

Figure 2

The sea surface temperature anomalies in the eastern equatorial Pacific are evolving this year more like the 1982/83 El Niño. The NINO1+2 data for 1997 shows east Pacific sea surface temperatures warmed much sooner during the 1997/98 El Niño.

The 1982/83 El Niño was strong, there’s no doubt about that, but it was nowhere close to being comparable to the 1997/98 El Niño as an east Pacific event.

A couple of things to keep in mind: First, there are subtle differences between El Niño events. It’s still very early in the evolution this year to make predictions of how strong the 2014/15 El Niño will eventually become.

Second, before you look at global surface temperature data and conclude that the 1982/83 El Niño had a very small effect on global surface temperatures, compared to the 1997/98 El Niño, keep in mind that the 1982/83 El Niño was counteracted by the eruption of El Chichon that year and there was no colossal explosive volcano in 1997 to offset the 1997/98 El Nino.

EARLIER POSTS IN THIS SERIES

• The 2014/15 El Niño – Part 1 – The Initial Processes of the El Niño.
• The 2014/15 El Niño – Part 2 – The Alarmist Misinformation (BS) Begins

FURTHER READING

My ebook Who Turned on the Heat? goes into much more detail to explain El Niño and La Niña processes and the long-term aftereffects of strong El Niño events. I’ve lowered the price of Who Turned on the Heat? from U.S.$8.00 to U.S.$5.00…with hope of increasing sales a little bit.  A free preview in pdf format is here.  The preview includes the Table of Contents, the Introduction, the first half of section 1 (which was provided complete in the post here), a discussion of the cover, and the Closing. Take a run through the Table of Contents.  It is a very-detailed and well-illustrated book—using data from the real world, not models of a virtual world. Who Turned on the Heat? is only available in pdf format…and will only be available in that format.  Click here to purchase a copy.  Thanks.