Archive for the ‘The Pause’ Category

Dig and Delve Part 1: Running Trends

December 22, 2016

This is the first in a series of posts in which I look at monthly Temperature of the Lower troposphere (TLT) anomaly data from the University of Alabama- Huntsville (UAH) in different ways, which readers may find interesting and perhaps useful.

In this post, I bring together ideas from former posts- Trending Trends: An Alternative View and Poles Apart – to compare trends in TLT using running trends.

 

Running Trends

Fig. 1: Global UAH with linear trend

linear-trend-global

This is the standard presentation.  It shows the linear trend as at November 2016.  With every new month of data, the linear trend changes.

By calculating a running trend, that is, the linear trend from the start of the series to every subsequent data point, the trend at each point is preserved, and the trend at the final point is instantly calculated.

Fig. 2:  Global UAH running trend

running-trend-global

Figure 2 shows the historical values of the linear trend at each point, and that global temperatures are demonstrably non-linear.  As I pointed out in Trending Trends: An Alternative View, each new data point will either increase, decrease, or maintain the trend.  The longer the data series, the harder it will be to change the trend: the effect diminishes with time.

(An interesting result of the diminishing effect of temperature on the running trend is that it becomes possible to identify what temperatures are doing from the shape of the running trend plot- in fact, to identify a pause or plateau.  To maintain the trend at say 1.2 degrees Celsius per 100 years, temperatures must continue to rise.  A flat-lining running trend is evidence of increasing temperatures; a rising running trend indicates a rapid increase in temperature; but a decreasing running trend is evidence of a pause or decline in temperatures.  This is not a different definition of the pause, just another indicator.)

For 10 to 15 years, the running trend swings wildly, but after this it settles.  Now it becomes useful for analysis and comparison.

In Figure 2 above, note the large effect of the 1997-98 El Nino on the trend, but the 2009-10 and 2015-16 El Ninos have much less effect on the trend.  They are still identifiable by the increase in trend.

Fig. 3:  Regional UAH running trends

running-trend-all-regions

As we have seen previously, the North Polar and South Polar regions are distinctly different from the rest of the world and from each other.  The North Polar region has had an increasing trend (rapidly increasing temperature) from 1994 to about 2007, then a slow down with another rapid rise in the last 12 months.  All other regions have had decreasing trends since 2002-3, with an uptick in the last 12-18 months, indicating the duration of The Pause.  The trend in the South Polar region has been much lower than the others, hovering about zero for the last seven or so years, and is currently negative.

For completeness, here are the running trends for continental USA and Australia.

Fig. 4:  UAH running trends:  USA 48 States

running-trend-usa48

Fig. 5:  UAH running trends:  USA 49 States

running-trend-usa49

Fig. 6:  UAH running trends:  Australia

running-trend-aus

The next plots compare Land, Ocean, and Mean running trends for the UAH regions.

Fig. 7:  Global UAH running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-global

Note that the mean trend is close to that of the Ocean, but since 1995 and especially 1998, the trend of global land areas is much higher.  Because of the ocean’s large thermal inertia, land areas warm and cool more quickly.  However, since the 1997-98 El Nino, land trends did not decrease but remained high until 2007.  This graph, as any Global Warming Enthusiast (GWE) will tell you, is evidence of warming.  What they won’t tell you is that it is evidence of any type of warming whether natural or anthropogenic- it is not by itself evidence of greenhouse warming.

Fig. 8:  Northern Hemisphere UAH running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-nh

Fig. 9:  Southern Hemisphere UAH running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-sh

Land trends in the Southern Hemisphere, unlike the Northern, did decrease after the 1997-98 El Nino.

Fig. 10:  Tropical UAH (20N – 20S) running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-tropics

Fig. 11:  Northern Extra-Tropics UAH (20N – 90N) running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-next

Fig. 12:  Southern Extra-Tropics UAH (20S – 90S) running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-sext

This region warmed rapidly to 2002-3, then trends decreased.

Fig. 13:  North Polar UAH (60N – 90N) running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-np

Fig. 14:  South Polar UAH (60S – 90S) running trends: Mean Land, and Ocean

running-trend-land-ocean-mean-sp

In all tropical and northern regions, Land trends have been higher than Ocean trends since 1997-98 (2002 for South Polar and Southern Extra-Tropics).  However, North Polar Ocean trends have been higher than Land since 1998.  There is a greater area of ocean than land, and ocean areas have been warming more than land.  This is the opposite of what greenhouse theory predicts.  At the poles, where warming is expected to be greatest, only the North Pole is warming, and here the warming is not greatest over land, but over the ocean.

Summing up:

  • Running trends are an effective way of showing the linear trend at any given month of a data series.
  • They are useful for comparison and analysis after the first 10 to 15 years (the early 1990s).
  • A declining running trend indicates flat or declining temperatures, thus The Pause is visible from 2002-3 to 2014-5 in all regions apart from North Polar.
  • The North and South Polar regions are distinctly different from other regions and each other.
  • Apart from North Polar region, all regions show land areas warming more than ocean areas, indicating warming from whatever cause.
  • In the North Polar region, TLT running trends of ocean areas have been higher than land.
  • These trends, especially at the poles, are not consistent with greenhouse theory.

 

The next post in this series will use running trends to derive running detrended data.

The Pause Update: November 2016

December 3, 2016

The complete UAH v6.0 data for November were released yesterday evening- the quickest ever. I present all the graphs for various regions, and as well summaries for easier comparison. The Pause has ended globally and for the Northern Hemisphere, and the Tropics, and may soon disappear from the USA, but still refuses to go away in the Southern Hemisphere.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 38 years long- 456 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are October 2016.

[CLICK ON IMAGES TO ENLARGE]

Globe:

pause-nov-16-globe

The Pause has ended. A trend of +0.28 C/100 years (+/- 0.1C) since March 1998 is creeping up.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies:

pause-nov-16-globe-monthly

Northern Hemisphere:

pause-nov-16-nh

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

pause-nov-16-sh

For well over half the record, the Southern Hemisphere still has zero trend.  The Pause has shortened by two months and may end shortly.

Tropics:

pause-nov-16-tropics

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +.27C/ 100 years.

Tropical Oceans:

pause-nov-16-tropic-oceans

The Pause has ended for ocean areas.

Northern Extra Tropics:

pause-nov-16-next

The minimal trend is up to +0.56C/ 100 years.

Southern Extra Tropics:

pause-nov-16-sext

The Pause persists.

Northern Polar:

pause-nov-16-np

The trend has increased a lot to +2.32C and since February 2003 +0.7C/100 years.

Southern Polar:

pause-nov-16-sp

The South Polar region has been cooling for the entire record.

USA 49 States:

pause-nov-16-usa49

The Pause has shortened by one month and is about to disappear altogether.

Australia:

pause-nov-16-oz

One month longer- 21 years 5 months.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

pause-length-nov-16

Note that the Pause has ended by my criteria in all regions of Northern Hemisphere, and consequently the Globe, and the Tropics, but all southern regions have a Pause for over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

trends-78-now-nov-16

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

trends-98-now-nov-16

The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for more than 18 years- just shy of half the record.

Global TLT anomalies have remained stubbornly high.  The next few months will be interesting. The Pause may disappear from the USA and Southern Hemisphere soon, but not the Southern Extra-Tropics or Australia. El Nino tropical heat is strongly affecting the North Polar region now, and will begin to affect the Southern Hemisphere early next year.

The Pause Update: October 2016

November 12, 2016

The complete UAH v6.0 data for October have just been released. I present all the graphs for various regions, and as well summaries for easier comparison. The Pause has ended globally and for the Northern Hemisphere, and the Tropics, but still refuses to go away in the Southern Hemisphere.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 11 months long- 455 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are October 2016.

[CLICK ON IMAGES TO ENLARGE]

Globe:

pause-oct-16-globe

The Pause has ended. A trend of +0.23 C/100 years (+/- 0.1C) since March 1998 is about one fifth of the trend for the whole record.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies:

pause-oct-16-globe-monthly

Northern Hemisphere:

pause-oct-16-nh

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

pause-oct-16-sh

For well over half the record, the Southern Hemisphere still has zero trend.  The Pause may end shortly.

Tropics:

pause-oct-16-tropics

The Pause in the Tropics (20N to 20S) has ended.

Tropical Oceans:

pause-oct-16-tropic-oceans

The Pause has ended for ocean areas.

Northern Extra Tropics:

pause-oct-16-nextt

The minimal trend is creeping up- how high will it go before decreasing again?

Southern Extra Tropics:

pause-oct-16-sextt

The Pause persists.

Northern Polar:

pause-oct-16-np

The trend has increased a lot.

Southern Polar:

pause-oct-16-sp

The South Polar region has been cooling for the entire record- 37 years.

USA 49 States:

pause-oct-16-usa49

No change.

Australia:

pause-oct-16-oz

No change.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

pause-oct-16-length

Note that the Pause has ended by my criteria in all regions of Northern Hemisphere, and consequently the Globe, and the Tropics, but all southern regions have a Pause for over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

trends-78-now-oct-16

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

trends-98-now-oct-16

The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for more than 18 years- just shy of half the record.

The next few months will be interesting. The Pause may disappear from the Southern Hemisphere soon. The behaviour of the Tropics and the South Polar regions will be crucial.  (I would like to see separate data for the Extra-tropical regions from 20 to 60 degrees north and south.)

The Pause Update: September 2016

October 18, 2016

The complete UAH v6.0 data for September have just been released. I present all the graphs for various regions, and as well summaries for easier comparison. The Pause has finally ended globally and for the Northern Hemisphere, and the Tropics, but still refuses to go away in the Southern Hemisphere.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 10 months long- 454 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are September 2016.

[CLICK ON IMAGES TO ENLARGE]

Globe:

pause-sep16-globe

The Pause has ended. A trend of +0.18 C/100 years (+/- 0.1C) since March 1998 is about one sixth of the trend for the whole record.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies:

pause-sep16-globe-monthly

Northern Hemisphere:

pause-sep16-nh

The Northern Hemisphere Pause has ended.

Southern Hemisphere:

pause-sep16-sh

For well over half the record, the Southern Hemisphere still has zero trend.  The Pause may end shortly.

Tropics:

pause-sep16-tropics

As expected, the Pause in the Tropics (20N to 20S) has ended.

Tropical Oceans:

pause-sep16-tropic-oceans

The Pause remains (just) for ocean areas.

Northern Extra Tropics:

pause-sep16-next

The minimal trend is creeping up- how high will it go before decreasing again?

Southern Extra Tropics:

pause-sep16-sext

The Pause is one month longer.

Northern Polar:

pause-sep16-np

Another big increase in temperature in this region but the minimal trend is still one seventh that of the whole record.

Southern Polar:

pause-sep16-sp

The South Polar region has been cooling for the entire record- 36 years 11 months.

USA 49 States:

pause-sep16-usa49

One month shorter.

Australia:

pause-sep16-oz

No change.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

pause-length-sep16

Note that the Pause has ended by my criteria in all regions of Northern Hemisphere, and consequently the Globe, and the Tropics, but all southern regions have a Pause for over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

trends-78-now

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

trends-jun-98-sep-16

The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for more than 18 years- just shy of half the record.

The next few months will be interesting. The Pause may disappear from the Southern Hemisphere soon. How long will the Pause last in the Southern Extra Tropics and South Polar regions?  ( I would like to see separate data for the Extra-tropical regions from 20 to 60 degrees north and south.)

The Pause Update: August 2016

September 12, 2016

The complete UAH v6.0 data for August were released on yesterday. I present all the graphs for various regions, and as well summaries for easier comparison. The Pause has finally ended globally and for the Northern hemisphere, but still refuses to go away in the Southern Hemisphere.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 9 months long- 453 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are August 2016.

[CLICK ON IMAGES TO ENLARGE]

Globe:

pause-aug-16-globe

The Pause has ended. A trend of +0.13C/100 years (+/- 0.1C) since March 1998 must make GWEs tremble with joy.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies:
pause-aug-16-globe-monthly

Still +0.33C/100 years since December 1997- not exactly alarming. The Pause will return sooner with monthly anomalies than 12 month means of course.

Northern Hemisphere:

pause-aug-16-nh

The Northern Hemisphere Pause has ended. Note the not very alarming warming of 0.33C +/- 0.1C per 100 years for half the record compared with 1.39C for the whole period.

Southern Hemisphere:

pause-aug-16-sh

For well over half the record, the Southern Hemisphere has zero trend.

Tropics:

pause-aug-16-tropics

The Pause has shortened again with the El Nino influence, but is still over half the record. However, don’t be surprised if the Pause disappears next month.

Tropical Oceans:

pause-aug-16-tropic-oceans

The Pause has shortened by another 3 months- the El Nino now having a strong effect on the 12 month means.

Northern Extra Tropics:

pause-aug-16-nh-extt

The Pause by this criterion has ended in this region, however note that the slope since 1998 is +0.39 +/- 0.1C per 100 years compared with +1.61C for the whole period- a quarter of the rate.

Southern Extra Tropics:

pause-aug-16-sh-extt

No change.

Northern Polar:

pause-aug-16-np

The Pause has ended in this region. (No cause for celebration- we definitely would not want to see cooling here!)

Southern Polar:

pause-aug-16-sp

The South Polar region has been cooling for the entire record- 36 years 10 months.

USA 49 States:

pause-aug-16-usa49

No change in length of the Pause.

Australia:

pause-aug-16-oz

No change here either.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

pause-length-aug-16

Note that the Pause has ended by my criteria in all regions of Northern Hemisphere, and consequently the Globe, but the Tropics and all southern regions have a Pause for over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

trends-78-to-now

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

trends-98-to-now

The only region to show strong warming for this period (18 years 3 months) is the North Polar region: the Northern Extra Tropics, Tropics, the Northern Hemisphere, and the Globe have mild warming but all other regions (including all of the Southern Hemisphere) are Paused or cooling. The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for more than 18 years- just shy of half the record.

The next few months will be interesting. The Pause should disappear from the Tropics next month and the Southern Hemisphere should follow. How long will the Pause last in the Southern Extra Tropics and South Polar regions?

The Pause Update: July 2016

August 7, 2016

The complete UAH v6.0 data for July were released on Friday.  I present all the graphs for various regions, and as well summaries for easier comparison.  The Pause still refuses to go away, despite all expectations.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 8 months long- 452 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are July 2016.

 [CLICK ON IMAGES TO ENLARGE]

Globe:

Pause july 16 globe

The Pause is 3 months shorter.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies, which shows that The Pause is over by my rather strict criterion:

Pause july 16 globe monthly

+0.33C/100 years since December 1997- not exactly alarming.  The Pause will return sooner with monthly anomalies than 12 month means of course.

Northern Hemisphere:

 

Pause july 16 nh

The Northern Hemisphere Pause has ended as expected.  Note the not very alarming warming of 0.28 +/- 0.1C per 100 years for half the record compared with 1.38C for the whole period.

Southern Hemisphere:

Pause july 16 sh

The Pause has shortened by another 4 months, but still, for well over half the record, the Southern Hemisphere has zero trend.

Tropics:

Pause july 16 tropics

The Pause has shortened by another 2 months with the El Nino influence, but is still over half the record.

Tropical Oceans:

Pause july 16 tropic ocean

The Pause has shortened by another 3 months- the El Nino now having a strong effect on the 12 month means.

Northern Extra Tropics:

Pause july 16 NH Ext tropics

The Pause by this criterion has ended in this region, however note that the slope since 1998 is +0.34 +/- 0.1C per 100 years compared with +1.6C for the whole period.  That’s still embarassingly slow warming.

Southern Extra Tropics:

Pause july 16 SH Ext tropics

The Pause has lengthened again by another month.

Northern Polar:

Pause july 16 NP

The Pause has decreased by 1 month.

Southern Polar:

Pause july 16 SP

The South Polar region has been cooling for the entire record- 36 years 9 months.

USA 49 States:

Pause july 16 USA

The Pause is 2 months shorter.

Australia:

Pause july 16 Oz

The Australian Pause is one month longer.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

Pause length jul16

Note that the Pause has ended by my criteria in the Northern Extra Tropics and the Northern Hemisphere, but apart from the North Polar region, all other regions have a Pause for over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

Trends 1978 july 16

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

Trends 1998 july 16

The only region to show strong warming for this period (18 years 2 months) is the North Polar region: the Northern Extra Tropics, Tropics, the Northern Hemisphere, and the Globe have very mild warming but all other regions (including all of the Southern Hemisphere) are Paused or cooling. The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for more than 18 years- just shy of half the record.

And finally, here is a plot of Global UAH versus CO2 concentration at Cape Grim from January 1996 to June 2016:

UAH vs C Grim co2 to 1996 June 2016

Now that’s a Pause!

Interim Pause Update: July 2016

August 2, 2016

This is a brief initial post with the UAH data for July 2016 with Global, Northern Hemisphere, Southern Hemisphere, and Tropical data only, which were released this morning.  I will post all graphs when the full dataset is available in about one week’s time.

Globe:

Pause july 16 globe

The Pause is hanging on but the trend will probably go above +0.1C per 100 years next month.

Northern Hemisphere:

Pause july 16 nh

The Pause is over, but the trend for the past 18 years and 3 months is +0.28C, which is about one fifth of the trend for the whole satellite period.

Southern Hemisphere:

Pause july 16 sh

The Pause has shortened by 4 months to 20 years and 2 months.

Tropics:

Pause july 16 tropics

The Pause has decreased to 19 years 1 month.

All graphs will be available shortly.

Temperature Variation Due to ENSO

July 25, 2016

In this post I use the Multivariate ENSO Index (MEI) supplied by NOAA at http://www.esrl.noaa.gov/psd/enso/mei/index.html and lower tropospheric temperature data supplied by UAH to show how much of temperature variation over the past 20 years is due to ENSO and how little is due to CO2.  I will keep words brief and let graphics do the talking.

Firstly, here is the MEI data from 1950:

Fig. 1:  Monthly MEI from 1950

mei monthly

As an aside, this is how it compares with SOI data.  The SOI is inverted and both are scaled for comparison.

Fig. 2:  MEI compared with SOI inverted

mei vs soi

Now compare scaled MEI with Global UAH:

Fig. 3: MEI (scaled) and UAH

mei monthly w uah

Notice tropospheric temperatures appear to lag the MEI by some 5 months:

Fig. 4: MEI advanced 5 months and UAH

mei monthly advd 5m w uah graph

Notice both datasets are noisy, and there is a clear discrepancy in the early 1990s.  12 month running means show this more clearly:

Fig. 5:  12 month means of UAH and MEI advanced 5 months:

mei advd w uah 12m

The slump in UAH data is shown by the arrow.  Mt Pinatubo’s main eruption was in June 1991. (Without El Chichon in 1982, there may well have been a much higher spike in the mid-1980s).

Now let’s look at the correlation between monthly MEI and UAH.  Firstly, the whole period from December 1978:

Fig. 6:  UAH vs MEI advanced 5 months 1978 – 2016

mei monthly advd 5m w uah

About 13% of temperature variation is associated with MEI variation.  Doesn’t tell us much does it.  What if we exclude the UAH data for two years from April 1982, and from July 1991 to December 1995?

Fig. 7:  UAH vs MEI advanced 5 months 1978 – 2016 with periods after volcanic eruptions excluded

mei monthly advd 5m v uah excl volcanoes

Considering the fluctuations in both datasets, that shows a fairly strong correlation.

Next, we examine the periods, before, during, and after the Pinatubo influence.

Fig. 8:  :  UAH vs MEI advanced 5 months December 1978 – June 1991, excluding April 1982 to March 1984

mei monthly advd 5m w uah 78-91

Again we see a similar correlation.

Fig. 9:  UAH vs MEI advanced 5 months July 1991 – December 1995

mei monthly advd 5m w uah 91-95.jpg

The strong positive correlation of the previous plots has broken down.

Fig. 10:  UAH vs MEI advanced 5 months January 1996 – June 2016

mei monthly advd 5m w uah 96-16

The correlation is even higher.  Over half of temperature variation is associated with ENSO variation five months previously.  Here is the same 1996-2016 plot but with 12 month running means:

Fig. 11  UAH vs MEI advanced 5 months January 1996 – June 2016, with 12 month running means

mei  advd 5m w uah 96-16 12m

74% of temperature variation for the past 20 years and 6 months can be explained by previous ENSO variation alone.  In the same period, carbon dioxide concentration at Mauna Loa has increased by 44.77 ppm, which is more than 49% of the entire increase from 1958, and Global temperature as measured by UAH has increased by a little over 0.1 degree C.

No wonder Global Warming Enthusiasts were pinning their hopes on the 2015-16 El Nino to put an end to the Pause, but they must also hope for the ENSO- temperature correlation to break down shortly, as a deep La Nina will mean cooler temperatures and further embarrassment for them.  However, the correlation breaks down when volcanoes cause lower temperatures in El Nino conditions as we have seen, but what mechanism could there be for higher temperatures in La Nina conditions?  Perhaps that magical greenhouse gas CO2?  That would indeed be spectacular- there are no outliers at the low end of any of the above plots.  The most UAH has been higher than expected with low MEI is about +0.2C to +0.3C, and those values cannot be described as outliers.  Besides, UAH for June is already down to +0.34C, and we are only four months past the peak- the cooling has barely begun.

Finally, this is a plot of the centred 37 month mean MEI (because La Ninas can last for three years).

Fig. 12: 37 month centred mean MEI

mei 37m avg

Notice that before 1975 the 37 month average never exceeded +0.5, the majority of the time was in negative territory, and in the 1950s and 1970s reached below -1.0.  Since 1975 the MEI has dropped below -0.5 only once in 2000 and approached -0.5 in 2012, but has been in positive territory for the vast majority of the time, exceeded +0.5 in six events, and was above +1.0 in the early 1990s.  It would be surprising if global temperatures had not seen a large increase.

How low will the monthly MEI go with the coming La Nina, and how low will the following global temperatures go?  All depends on La Nina’s length and strength, but the monthly MEI data are falling fast.  Stand by.

The Pause Update: June 2016

July 8, 2016

The complete UAH v6.0 data for June were released yesterday.  I present all the graphs for various regions, and as well summaries for easier comparison.  The Pause still refuses to go away, despite all expectations.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 7 months long- 451 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are June 2016.

 [CLICK ON IMAGES TO ENLARGE]

Globe:

pause jun16 globe

The 12 month mean to June 2016 remains at +0.46C and should stay at about this value for the next two months.  If so, The Pause, (now 1 month shorter), will continue to be an embarrassing reality! However, it may end soon after with a small positive trend.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies, which shows that The Pause is over by my rather strict criterion:

pause jun16 globe mthly

+0.3C/100 years since December 1997- not exactly alarming.  The Pause will return sooner with monthly anomalies than 12 month means of course.

Northern Hemisphere:

pause jun16 NH

The Northern Hemisphere Pause has ended as expected.  Note the not very alarming warming of 0.21 +/- 0.1C per 100 years for half the record compared with 1.37C for the whole period.

Southern Hemisphere:

pause jun16 SH

The Pause has shortened by 2 months.  For well over half the record the Southern Hemisphere has zero trend.

Tropics:

pause jun16 tropics

The Pause has shortened by another 3 months with the El Nino influence, but is still over half the record.

Tropical Oceans:

pause jun16 tropic oceans

The Pause has shortened by another 2 years- the El Nino now having a strong effect on the 12 month means.

Northern Extra Tropics:

pause jun16 NH ExtT

The Pause by this criterion has ended in this region, however note that the slope since 1998 is +0.29 +/- 0.1C per 100 years compared with +1.59C for the whole period.  That’s still embarassingly slow warming.

Southern Extra Tropics:

pause jun16 SH ExtT

The Pause has lengthened by another month.

Northern Polar:

pause jun16 NP

The Pause has decreased by 1 month.

Southern Polar:

pause jun16 SP

The South Polar region has been cooling for the entire record.

USA 49 States:

pause jun16 USA49

No change.

Australia:

pause jun16 Oz

The Australian Pause has not changed.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

Pause length jun 16

Note that the Pause has ended by my criteria in the Northern Extra Tropics and the Northern Hemisphere, but apart from the North Polar region, all other regions have a Pause of 18 years 8 months or longer- well over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

Trends 1978 jun 16

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

Trends 1998 jun 16

The only region to show strong warming for this period (18 years 1 month) is the North Polar region: the Northern Extra Tropics, Tropics, and the Northern Hemisphere have very mild warming but all other regions (including the Globe as a whole and all of the Southern Hemisphere) are Paused or cooling. The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for more than 18 years.

12 month means will continue to grow in some regions for the next few months, so the Pause as here defined may end in some regions shortly (probably North Polar, Tropics, and Tropical Oceans), and may not reappear until early 2018.  The impact of the coming La Nina will be worth watching.  Unless temperatures reset at a new, higher level and continue rising, very low trends will remain.

The Pause Update: May 2016

June 5, 2016

The complete UAH v6.0 data for May were released on today.  I present all the graphs for various regions, and as well summaries for easier comparison.  The Pause still refuses to go away, despite all expectations.

These graphs show the furthest back one can go to show a zero or negative trend (less than 0.1 +/-0.1C per 100 years) in lower tropospheric temperatures. I calculate 12 month running means to remove the small possibility of seasonal autocorrelation in the monthly anomalies. Note: The satellite record commences in December 1978- now 37 years and 6 months long- 450 months. 12 month running means commence in November 1979. The y-axes in the graphs below are at December 1978, so the vertical gridlines denote Decembers. The final plotted points are May 2016.

 [CLICK ON IMAGES TO ENLARGE]

Globe:

May16 globe

The 12 month mean to May 2016 is +0.46C.  The Pause is still an embarrassing reality! However, it may “disappear” soon with a small positive trend.

And, for the special benefit of those who think that I am deliberately fudging data by using 12 month running means, here is the plot of monthly anomalies, which shows that The Pause is over by my rather strict criterion:

May16 globe mthly

+0.27C/100 years since December 1997- not exactly alarming.  The Pause will return sooner with monthly anomalies than 12 month means of course.

Northern Hemisphere:

May16 NH

The Northern Hemisphere Pause has “disappeared” as expected.  Note the not very alarming warming of 0.14+/- 0.1C per 100 years for half the record compared with 1.35C for the whole period.

Southern Hemisphere:

May16 SH

The pause has shortened by one month.  For well over half the record the Southern Hemisphere has zero trend.

Tropics:

May16 Tropics

The Pause has shortened dramatically with the El Nino influence, but is still over half the record.

Tropical Oceans:

May16 Tropic oceans

The Pause has shortened by 19 months.

Northern Extra Tropics:

May16 Nth ExTropics

The Pause by this criterion has ended in this region, however note that the slope since 1998 is +0.23 +/- 0.1C per 100 years compared with +1.58C for the whole period.  That’s still embarassingly slow warming.

Southern Extra Tropics:

May16 Sth ExTropics

The Pause has lengthened by another month.

Northern Polar:

May16 NP

The Pause has decreased by 2 months.

Southern Polar:

May16 SP

The South Polar region has been cooling for the entire record.

USA 49 States:

May16 USA49

No change.

Australia:

May16 Oz

The Australian Pause has lengthened rapidly.

The next graphs summarise the above plots. First, a graph of the relative length of The Pause in the various regions:

Pause length may16

Note that the Pause has ended by my criteria in the Northern Extra Tropics and the Northern Hemisphere, but apart from the North Polar region, all other regions have a Pause of 18 years 9 months or longer- well over half the record, including the South Polar region which has been cooling for the whole record.

The variation in the linear trend for the whole record, 1978 to the present:

Trends 1978 may16

Note the decrease in trends from North Polar to South Polar.

And the variation in the linear trend since June 1998, which is about halfway between the global low point of December 1997 and the peak in December 1998:

Trends Jun98 may16

The only region to show strong warming for this period (18 years) is the North Polar region: the Northern Extra Tropics and the Northern Hemisphere have very mild warming but all other regions are Paused or cooling. In fact “global” warming since June 1998 is limited to that part of the globe north of 20 degrees North.  And the lower troposphere over Australia has had strong cooling for the past 18 years.

12 month means will continue to grow for the next few months, so the Pause as  here defined may disappear shortly, and may not reappear until early 2018.  The impact of the coming La Nina will be worth watching.  Unless temperatures reset at a new, higher level and continue rising, very low trends will remain.