Guest Post by Bob Tisdale
This post compares the responses of global surface temperature anomalies and lower troposphere temperature anomalies for the 2015/16 El Niño and the comparatively strong 1997/98 El Niño. Datasets included are lower troposphere temperature data from RSS and UAH and land-ocean surface temperature products from NASA GISS, NOAA NCEI and UK Met Office.
Referring to the sea surface temperatures of the NINO3.4 region of the east/central equatorial Pacific, the current 2015/16 El Niño is comparable in strength to the 1982/83 and 1997/98 El Niños. Due to the differences between sea surface temperature datasets, however, it is impossible to know which El Niño is actually the strongest. (See the post here.)
In this post, we’re comparing the evolutions of global surface temperature anomalies (GISS LOTI, NOAA NCEI, and UKMO HADCRUT4) and lower troposphere temperature anomalies (RSS and UAH) for 24-month periods starting in 1997 and 2015. We’re excluding the responses to the 1982/83 El Niño because the 1982 eruption of El Chichon impacted global surface temperatures in those two years. To better align the data for comparison purposes, the data are referenced (zeroed) to the average temperature anomalies for the January to October of 1997 and 2015. The top graphs in each of the figures include the monthly data. Due to the volatility of the some datasets, the bottom graphs include the data smoothed with 3-month running-average filters. I’ve listed the global temperature difference between 1997 and 1998 in the top graphs, so that you can get an idea of the expected rises in global surface temperatures from 2015 to 2016.
Due to data availability, the end months of the data in 2015 vary.
Let’s start with the…
LOWER TROPOSPHERE TEMPERATURE ANOMALIES
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We should expect lower troposphere temperatures to continue to rise through March/April of 2016 and then decline through 2016…and then continue to drop into 2017 in response to the 2016/17 La Niña, assuming one forms (reasonable assumption).
LAND+OCEAN SURFACE TEMPERATURES
Figure 3 includes the GISS Land-Ocean Temperature Index (data here). The NOAA/NCEI land+ocean surface temperature data (here) are shown in Figure 4. Both the GISS and NOAA data are available through November 2015. The UKMO as of this writing still have not published their November 2015 HadCRUT4 data (here), so they end in October in Figure 5.
Note that the scales of the y-axis are smaller in Figures 3 to 5 than they were in Figures 1 and 2.
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We might expect the global surface temperatures to peak in February or March of 2016, assuming 2016 surface temperatures mimic those of 1998. Surface temperatures remained elevated through to the second half of 1998, when they began to show noteworthy drops. Once again, we could expect surface temperatures to continue to drop in 2017 is response to the 2016/17 La Niña…if one forms, which is likely.
The responses of global surface and lower troposphere temperatures in 2015 are what we would expect for a strong El Niño. In 2016, if global surface and lower troposphere temperatures continue to respond as they had to the 1997/98 El Niño, we can expect global surface and lower troposphere temperatures to be higher in 2016 than they were in 2015.
I’ll try to update these graphs every couple of months.
FOR THOSE NEW TO DISCUSSIONS OF EL NIÑO EVENTS
I discussed in detail the naturally occurring and naturally fueled processes that cause El Niño events (and their long-term aftereffects) in Chapter 3.7 of my recently published free ebook On Global Warming and the Illusion of Control (25 MB). For those wanting even more detail, see my earlier ebook Who Turned on the Heat? – The Unsuspected Global Warming Culprit: El Niño-Southern Oscillation. Who Turned on the Heat? only costs $5.00 (US).