Archive for the ‘uah’ Category

The Pause Update: February 2017

March 4, 2017

The complete UAH v6.0 data for February have been released. I present all the graphs for various regions, and as well summaries for easier comparison. I also include graphs for the North and South Temperate regions (20-60 North and South), estimated from Polar and Extra-Tropical data.

The Pause has ended globally and for all regions including the USA and the Southern Hemisphere, except for Southern Extra-Tropics, South Temperate, South Polar, and Australia. The 12 month mean to February 2017 for the Globe is +0.44 C.

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 and three months long- 459 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 February 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

feb-17-globe

The Pause has ended. A trend of +0.39 C/100 years (+/- 0.1C) since March 1998 is creeping up, but the 12 month means have peaked and are heading down.

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:

feb-17-globe-monthly

Northern Hemisphere:

feb-17-nh

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

feb-17-sh

The Pause has ended- just.

Tropics:

feb-17-tropics

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +0.4C/ 100 years. 12 month means are dropping fast.

Northern Extra Tropics:

feb-17-next

Northern Temperate Region:

feb-17-n-temp

Using estimates calculated from North Polar and Northern Extra-Tropics data, the slowdown is obvious.

Southern Extra Tropics:

feb-17-sext

The Pause has weakened and may soon disappear.

Southern Temperate Region:

feb-17-s-temp

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause is shorter than for Southern Extra-Tropics.

Northern Polar:

feb-17-np

The trend has increased rapidly and will continue to do so even though 12 month means have started to fall.

Southern Polar:

feb-17-sp

The South Polar region has been cooling (-0.2C) for the entire record. With 12 month means still rising, this cooling trend will slow over the next few months.

USA 49 States:

feb-17-usa49

The Pause has ended. It will not re-appear for some time.

Australia:

feb-17-oz

The Pause is still 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:

feb-17-pause-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. Note that the Tropic influence has been enough to end the Pause for the Southern Hemisphere.

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

feb-17-trends-78

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:

feb-17-trends-98

The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for 18 years and 9 months- just shy of half the record.
The Pause has disappeared from the USA and the Southern Hemisphere, but not the Southern Extra-Tropics, South Temperate, and South Polar regions, or Australia. El Nino tropical heat is rapidly decreasing, with all northern means falling, but will continue to affect the Southern Hemisphere in coming months.  Global TLT anomalies have increased a little.   The next few months will be interesting.

 

 

The Pause Update: January 2017

February 12, 2017

The complete UAH v6.0 data for January have been released. I present all the graphs for various regions, and as well summaries for easier comparison. I also include graphs for the North and South Temperate regions (20-60 North and South), estimated from Polar and Extra-Tropical data.

The Pause has ended globally and for all regions including the USA and the Southern Hemisphere, except for Southern Extra-Tropics, South Temperate, South Polar, and Australia. The 12 month mean to January 2017 for the Globe is +0.48 C.

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 and two months long- 458 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 January 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

pause-globe-jan17

The Pause has ended. A trend of +0.36 C/100 years (+/- 0.1C) since March 1998 is creeping up, but the 12 month means have peaked and are heading down.

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-globe-jan17-monthly

That’s since December 1997.

Northern Hemisphere:

pause-nh-jan17

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

pause-sh-jan17

The Pause has ended- just.

Tropics:

pause-jan17-tropics

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +.39C/ 100 years. 12 month means are dropping fast.

As Tropical Oceans closely mimic the Tropics overall, I won’t show their plot.

Northern Extra Tropics:

pause-jan17-next

The minimal trend is up to +0.64C/ 100 years= that’s one degree less than the whole trend.

Northern Temperate Region:

pause-jan17-ntemp

Using estimates calculated from North Polar and Northern Extra-Tropics data, while the trend since June 1998 of +0.28 +/- 0.1C per 100 years is more than my criterion for a Pause, it is 1.2C less than the trend for the whole period. The slowdown is obvious, and for Land areas the trend is zero.

Southern Extra Tropics:

pause-jan17-sext

The Pause persists strongly, however 12 month means are still rising, and the Pause may shorten or even disappear.

Southern Temperate Region:

pause-jan17-stemp

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause is shorter than for Southern Extra-Tropics.

Northern Polar:

pause-jan17-np

The trend has increased rapidly and will continue to do so even though 12 month means have started to fall.

Southern Polar:

pause-jan17-sp

The South Polar region has been cooling for the entire record. With 12 month means still rising, this cooling trend will slow over the next few months.

USA 49 States:

pause-jan17-usa49

The Pause has ended- just. It will not re-appear for some time.

Australia:

pause-jan17-oz

The Pause is still 21 years 5 months. Heat in recent weeks may push the 12 month mean higher and shorten the Pause. (September, oops!)

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

pause-length-jan17

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. Note that the Tropic influence has been enough to end the Pause for the Southern Hemisphere.

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

trend-78-jan-17

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:

trend-98-jan-17

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 Pause has disappeared from the USA and Southern Hemisphere, but not the Southern Extra-Tropics, South Temperate, and South Polar regions, or Australia. El Nino tropical heat is rapidly decreasing, with all northern means falling, but will continue to affect the Southern Hemisphere in coming months.  Global TLT anomalies are now dropping rapidly. The next few months will be interesting.

Dig and Delve Part III: Temperate Regions

February 1, 2017

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.

The Pause Update: December 2016

January 5, 2017

The complete UAH v6.0 data for December have 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, and may soon disappear from the USA, and the Southern Hemisphere.  The 12 month mean to December 2016 for the Globe is +0.50 C.

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 and one month long- 457 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 December 2016.

[CLICK ON IMAGES TO ENLARGE]

Globe:

uah-dec-16-globe

The Pause has ended. A trend of +0.32 C/100 years (+/- 0.1C) since March 1998 is creeping up, but the 12 month means have peaked and are heading down.

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:

uah-dec-16-globe-monthly

That’s since December 1997.

Northern Hemisphere:

uah-dec-16-nh

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

uah-dec-16-sh

For well over half the record, the Southern Hemisphere still has zero trend.  The Pause is about to end.

Tropics:

uah-dec-16-tropics

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +.32C/ 100 years.  12 month means peaked mid-year.

As Tropical Oceans closely mimic the Tropics overall, I won’t show their plot.

Northern Extra Tropics:

uah-dec-16-next

The minimal trend is up to +0.6C/ 100 years.

Southern Extra Tropics:

uah-dec-16-sext

The Pause persists strongly, however 12 month means are still rising.

Northern Polar:

uah-dec-16-np

The trend has increased a lot to +2.35C and since February 2003 +0.88C/100 years.

Southern Polar:

uah-dec-16-sp

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

USA 49 States:

uah-dec-16-us49

The Pause has shortened again and is about to disappear altogether.

Australia:

uah-dec-16-oz

The Pause is still 21 years 5 months, and means have peaked.  Will the Australian Pause survive where others have failed?

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

pause-length-dec-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-dec-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-dec-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 are now dropping rapidly.  The next few months will be interesting. The Pause will 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 affect the Southern Hemisphere early this year.

Dig and Delve Part 2: Running Detrended Data

December 29, 2016

In my last post, Dig and Delve Part1, I showed how running trends are useful for showing the linear trend to any point in a dataseries, and that trends in different regions can be compared, after the first 10 to 15 years (120 to 180 datapoints).

In this post I use running trends to derive running detrended data, and analyse data for various Land regions using UAH anomalies.  Firstly, the following figure shows global mean UAH to November 2016 detrended using the current linear trend:

Fig. 1:  Global data detrended from linear trend

global-detrended-normal

This is the usual way to show detrended data.  It clearly shows where temperatures have been above or below the trend, however with each new data point the detrended data changes.  Running detrended data is calculated for each point as actual data minus  the running trend multiplied by the count of data points plus the running intercept.  Here is a plot of running detrended data and ordinary detrended data for Global UAH.

Fig. 2:  Global running detrended data and standard detrended data.

global-detrended-running-comp

After about 1987 they differ by less than +/- 0.1C, and UAH is accurate to +/- 0.1C anyway.   Note also that when temperatures are rising, running detrended data are greater and when falling, they are lower than standard detrended data.

The benefit of running detrended data is that they never have to be recalculated.  Historic detrended values are preserved.  As well, the running trend per month is conveniently not different from zero (which is why I showed it in Part 1 as degrees per 100 years by multiplying by 1,200), so it is easy to show the detrended data with a zero line.  The detrended value is also a measure of how much each month’s data has contributed to the trend- positive values indicate warming influence, negative values indicate cooling influence on the trend.

I now turn to using running detrended data to analyse what has been happening with Land data recently.

The following plots show running detrended data for Land TLT in the Northern Hemisphere.

Fig. 3:  Northern Hemisphere Land data detrended from running trend

nh-land-det

The large spike in February was followed by a plunge to October, but values in November have returned to trend.

Fig. 4:  Northern Extra Tropics Land data detrended from running trend

next-land-det

Similar to the Northern Hemisphere.

Fig. 5:  North Polar Land data detrended from running trend

np-land-det

Note how much North Polar data fluctuates.  However the Poles only contribute less than 7% to the Global mean.

Summing up:

  • Running detrended data never have to be recalculated, and historic values are preserved.
  • The detrended data show how much each month’s data has contributed to the trend at that point.
  • The recent plunge in Northern Hemisphere Land anomalies is nothing to get excited about as it is the recovery from a huge spike. The November value is still on trend.

The next in this series will use an estimate of discrete Extra Tropics (20-60 North and South) to look at trends and detrended data.

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.)

Poles Apart

November 4, 2016

Satellite data from UAH (University of Alabama- Huntsville) are estimates of temperature in the Lower Troposphere, and thus a good indicator of whether greenhouse warming is occurring.  My next post about the length of The Pause in various regions will be ready in a few days’ time.  Meanwhile, I’ve been looking at the data in a different way.

In this post I will be examining how and when temperatures have changed in discrete regions of the globe, including over land and over oceans.  There are no startling revelations, but a different approach reinforces the need to understand climate variability in different regions.  The important regions of course are the Tropics and the Poles, and fortunately UAH data is available separately for just these three regions.

Firstly, Figure 1 shows the regions for which UAH has atmospheric data.

Fig. 1:  UAH Data Regions

regions

The Northern and Southern Extra-Tropics include the Polar regions, so there are three discrete regions which do not overlap: Tropics, North Polar, and South Polar.  It would be very helpful if Dr Spencer provided data for the Extra Tropical regions excluding the Polar Regions.

For this analysis I use CuSum, which is a simple test of data useful for detecting linearity or otherwise, and identifying sudden changes in trend, or step changes.  It can be used for any data at all- bank balance, car accidents, rainfall, GDP, or temperature.  It is simple to use:  find the mean of the entire data, calculate differences for every data point from this mean, then calculate the running sum (Cumulative Sum) of the differences.  If done correctly, the final figure will be zero.  Plot the CuSum usually by time and identify points of any sudden change in direction.  A generally straight or smoothly curving line indicates linearity, but points of sudden change mean a change in trend or a step change.  (Further, data series with identical start and end points, exactly the same number of data points, and anomalies from the same period- such as UAH- should produce directly comparable CuSums.)  These points, and ranges between them, are then checked in the original data. The usefulness of CuSums will become obvious as we go, especially as they are compared.

The next figures show CuSum plots for various regions.

Fig. 2:  UAH CuSums for all regions

cusums-all

Points to note:

The brown line at the top is the South Polar region.  The line wobbles about zero, indicating little relative change in temperature from the mean.  Contrast this with the North Polar region (the blue line at the bottom.)  The Polar regions are conspicuously different from the other regions and from each other.

The spaghetti lines clustered in the middle are CuSums for (in order from top to bottom): Southern Extra-Tropics; Southern Hemisphere; Tropics; Globe; Northern Hemisphere; Northern Extra-Tropics.

The red arrows point to wobbles coinciding with major ENSO events.  These changes in direction indicate trend changes or step changes in the original data.  There are other changepoints, notably 2002-2003.

The vertical red line joins changepoints in all the CuSums in mid-1991 following the eruption of Mt Pinatubo.

Fig. 3: UAH CuSums for the Tropics, South Polar, and North Polar regions

cusums-np-sp-tropics

Note there is little similarity between CuSums for the only regions with discrete data, and you have to look carefully to see North Polar CuSums changing some months after Tropics, but not always.

The next plots show the differing responses of Land and Ocean areas.

Fig. 4:   UAH CuSums for the Globe, Land and Ocean

cusums-land-ocean

Note that Land areas have greater relative temperature changes than the Oceans, and that the Global mean closely mirrors the Ocean CuSums (as the Globe is mostly Ocean).  The major turning point is in 1997-98.

Fig. 5:  UAH CuSums for the Tropics, Land and Ocean

cusums-tropics-land-ocean

Note once again the mean CuSums closely follow that of the Ocean as 20 degrees North to 20 degrees South is mostly water.  The changepoints are very distinct.

Fig. 6:  UAH CuSums for the North Polar region, Land and Ocean

cusums-np-land-ocean

Note that all CuSums are close, but after 1982 Ocean CuSum changes relatively more than Land- the blue line has switched to below the mean.  The main changepoints are 1991, 1993-94, 2002, 2009, and 2015.

Fig. 7:  UAH CuSums for the South Polar region, Land and Ocean

cusums-sp-land-ocean

Now that is interesting.  Note all three CuSums have similar changepoints, but Land varies more than Ocean and after 1992 Land is largely negative, Ocean is largely positive.  The Land CuSum range is about half of the North Polar equivalent.

Remember CuSums in Figure 4 showed Land temperatures must vary more than Ocean (though not in the North Polar region).  The next figures show plots of UAH original data (not CuSums).

Fig. 8:  UAH original data for the Globe, Land and Ocean

graphs-globe-land-ocean

I find a visual representation demonstrates greater relative variation in Land temperatures well.

Fig. 9:  UAH original data for the Tropics, Land and Ocean

graphs-tropics-land-ocean

Note much greater fluctuation with ENSO, and Land varying a little more that Ocean.

Fig. 10:  UAH original data for the North Polar region, Land and Ocean

graphs-np-land-ocean

Note the much greater variation, but Land is more often than not masked by Ocean.

Fig. 11:  UAH original data for the South Polar region, Land and Ocean

graphs-sp-land-ocean

Note the much greater range in Land data, with large non-linear multi-year swings- calculate a linear trend for Land at your peril.

Having found changepoints, we can now analyse periods between them.  One way is to calculate means, and step changes between periods.

Fig. 12:  UAH original data for the Tropics based on CuSum changepoints

steps-tropics

I deliberately ignored the 2001 changepoint- it made very little difference to means and appears to be a continuation of the series starting in 1997.  Note the step changes are very small, and the final step change is reliant on current data and will change.  While I have shown means and steps, the data are decidedly non-linear with sharp spikes and multi-year rises and falls.

Fig. 13:  UAH original data for the North Polar region based on CuSum changepoints

steps-np

Note the large step change in the mid-1990s occurs before the 1997-98 El Nino.  The range is much greater than the Tropics.

As the Land data for the South Polar region looks more interesting, I decided to use Land instead of the mean.

Fig. 14:  UAH original data for the South Polar region (Land data) based on CuSum changepoints

steps-sp-land

Up and down like a toilet seat!

Conclusions:

The data series are characterised by step changes and multi-year rises and falls.

The Polar regions are “poles apart” in their climate behaviours.  Explanations might include: different geography (an ocean almost surrounded by land but subject to warming and cooling currents vs a continent isolated from the rest of the world by a vast ocean); different snow and ice albedo responses; different cloud influences.

The Global mean combines data from regions with very different climatic behaviour.  Averaging hides what is really going on.  The Tropics are governed by ENSO events, and the Poles are completely different.

Please Dr Spencer can you provide separate data for 20-60 degrees North and South?

Comments and interpretations are most welcome.

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?