Dig and Delve Part III: Temperate Regions

In this post I draw together ideas developed in previous posts- Poles Apart, Pause Updates, Dig and Delve Parts I and II– in which I lamented the lack of tropospheric data for the regions of the northern and southern hemispheres from 20 to 60 degrees North and South.  These regions between the Tropics and Polar regions I shall call Temperate regions, as that’s what I was taught in school.

A commenter of long standing, MikeR, who has always endeavoured to keep me on the straight and narrow, suggested a method of estimating temperature data for these regions using existing Polar and Extra-Tropical data.  I’ve finally got around to checking, and can now present the results.

The correct formula is:

T (20 to 60 degrees) = 1.256 x TexT ( 20 to 90 degrees) – 0.256 X T pole(60 to 90 degrees).

This gives an approximation for these regions in lieu of UAH data specifically for them.

And the results are very, very interesting.  Hello again, Pause.

All data are from the University of Alabama (Huntsville) (UAH) lower troposphere, V.6.0.

First of all, here are plots showing the Extra-Tropics (20-90), compared with  the corresponding Temperate regions (20-60).

Fig. 1:  Monthly UAH data for Northern Extra-Tropics (20-90N) and Estimate for Northern Temperate Region (20-60N)

 nth-temp-v-next

Fig. 2:  Monthly UAH data for Southern Extra-Tropics (20-90S) and Estimate for Southern Temperate Region (20-60S)

sth-temp-v-sext

As expected, the result of very slight differences is a slight cooling of the Northern Extra Tropics trend, and a slight warming for the Southern.   No surprise there.

The real surprise is in the Land and Ocean data.  In the Northern Temperate region, CuSum analysis reveals a large regime change which occurred at the beginning of 1998.  The following plots show trends in the data up to January 1998 and from February 1998 to December 2016.

Fig. 3: Estimated Northern Temperate data trends to January 1998 and from February 1998 to December 2016.

nth-temp-2-trends

Fig. 4: Estimated Northern Temperate data trends to January 1998 and from February 1998 to December 2016: Ocean areas.

nth-temp-2-trends-ocean

Fig. 5: Estimated Northern Temperate data trends to January 1998 and from February 1998 to December 2016: Land areas.

nth-temp-2-trends-land

Say hello to the Pause again.  Northern Temperate land areas- most of North America, Asia, Europe, and North Africa, containing the bulk of the world’s population, agriculture, industry, and CO2 emissions- has had zero trend for 18 years and 11 months.  While the trend for the whole record is +1.8C per 100 years, the record is clearly made of two halves, the first with a much milder +0.7C trend, then after an abrupt step change, the second half is flat- in spite of the “super El Nino” and the “hottest year ever”.

Compare this with the Extra-Tropics data, 20-90N.

Fig. 6: Northern Extra-Tropics data (20-90N) trends to January 1998 and from February 1998 to December 2016: Land areas.

next-land-2-trends

The step change is still there, but the trends are virtually unchanged- only 0.1C different +/- 0.1C.

Why the difference?  Northern Extra Tropics data (20-90N) includes the North Polar data (60-90N).  The major change in the North Polar region occurred in early 1995, as the next two figures show:

Fig. 7: Northern Polar data (60-90N) trends to February 1995 and from March 1995 to December 2016: Land areas.

np-land-2-trends

Fig. 8: Northern Polar data (60-90N) trends to February 1995 and from March 1995 to December 2016: Ocean areas.

np-ocean-2-trends

Massive changes in trend.  Note the change apparently occurred in land data before ocean, which is peculiar, and both in the dead of winter.  Polar regions, though much smaller, have a large impact on trends for the Extra-Tropics.

In the Southern part of the globe, once again say hello to the Pause.

Fig. 9: Estimated Southern Temperate data trends to January 1998 and from February 1998 to December 2016.

sth-temp-2-trends

While the step change is much smaller, using the same dates the Pause is still undeniable.

Fig. 10: Estimated Southern Temperate data trends to January 1998 and from February 1998 to December 2016- Land areas.

sth-temp-2-trends-land

Fig. 11: Estimated Southern Temperate data trends to January 1998 and from February 1998 to December 2016- Ocean areas.

sth-temp-2-trends-ocean

Most of the Southern Hemisphere is ocean, so it follows that a Pause in the ocean leads to a Pause overall.

It is important to stress that the figures I show for Northern and Southern Temperate regions are estimates, not actual data from UAH.  However, they are pretty good estimates, and until we have data from UAH, the best available.

Of the world’s regions, South Polar and Southern Temperate regions are paused, as is the Northern Temperate Land region, which is arguably the most important.  The Tropics fluctuate with ENSO.  Only the Arctic is strongly warming.

The Temperate regions are arguably the most important of the globe.  Together they cover more than half the surface area, and contain the bulk of the world’s population, agriculture, industry, and emissions.  I hope that Dr Spencer will be able to provide datasets for these regions as soon as possible.

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6 Responses to “Dig and Delve Part III: Temperate Regions”

  1. These items caught my eye – 2 February 2017 | grumpydenier Says:

    […] Click here to read the full article ____________________________ […]

  2. ngard2016 Says:

    Ken I hope Roy can give you the official data. But here’s another problem I’d like your opinion on.

    In 2010 Phil Jones had an interview Q&A with the BBC and listed the warming trends from 1850 to 2009. This during their Climategate fiasco.
    First trend was 1860 to 1880 0.163 c/ decade
    Second trend was 1910 to1940 0.150c
    Third trend was 1975 to 1998 0.166 c
    Fourth trend was 1975 to 2009 0.161 c.

    But now using the York uni tool the trends are——-

    1860 to 1880 0.113 c/dec
    1910 to 1940 0.129 c/dec
    1975 to 1998 0.172 c/dec
    1975 to 2009 0.188 c/dec

    Why have the two earlier trends dropped and particularly the first trend 1860 to 1880 has dropped from 0.163 c to 0.113c ? Of course later trends are now higher.
    I’m using HAD 4 L&O, but there is a global HAD 4 Krig and that shows a higher trend for 1860 to 1880 of 0.167 c.
    Just for interest I checked the trend from 1910 to 1945 and found it to be 0.140 c/dec or higher than Jones’s second trend is now. BTW HAD 4 global Krig was 0.151 c/ dec for 1910 to 1945. What is going on?

    Here’s Jones’s 2010 BBC Q&A link.

    http://news.bbc.co.uk/2/hi/science/nature/8511670.stm

  3. ngard2016 Says:

    And here is the York Uni data-base tool. Note that Cowton etc allowed RSS V4 TTT but not UAH V6, but only UAH V 5.6. Of course RSS V 3.3 TLT included.

    http://www.ysbl.york.ac.uk/~cowtan/applets/trend/trend.html

  4. kenskingdom Says:

    Your guess is as good as mine, but homogenising has had a similar effect on many datasets. Makes recent warming that little bit scarier.

  5. trevor Says:

    Have you looked at the Australian tidal station data —to me it seems that the air temperature median around Australia has not risen since the 12 stations were started in 1993. My suggestion is that CO2 has not raised temperatures over this period—hence other man made causes have increased temperatures.—-except the Willis island temperatures which have been falsely altered to compare with the land false data!!!!!!!!—-Trevor

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