Another Inconvenient Pause

The Pause in global temperatures may be past, but here is another, longer Pause, and one that is much more difficult to explain: at ideal Australian sites, increasing greenhouse gas concentrations have led to a decrease in downwelling longwave radiation- the very opposite of expectations.

Basically, the theory behind the enhanced greenhouse effect is that the increase in concentrations of anthropogenic greenhouse gases leads to an increase in downwelling infra-red (IR) radiation, which causes surface warming.

Is there evidence for increasing downwelling IR in recent years, as atmospheric concentration of carbon dioxide has been rapidly rising?

The authors of Skeptical Science think so:

Surface measurements of downward longwave radiation

A compilation of surface measurements of downward longwave radiation from 1973 to 2008 find an increasing trend of more longwave radiation returning to earth, attributed to increases in air temperature, humidity and atmospheric carbon dioxide (Wang 2009). More regional studies such as an examination of downward longwave radiation over the central Alps find that downward longwave radiation is increasing due to an enhanced greenhouse effect (Philipona 2004).

Time for a reality check.

The links in the above quote do not work for me, so I use data available for Australia.

Greenhouse gas concentrations are measured at Cape Grim in north-west Tasmania.  According to the CSIRO,

The Cape Grim station is positioned just south of the isolated north-west tip (Woolnorth Point) of Tasmania. It is in an important site, as the air sampled arrives at Cape Grim after long trajectories over the Southern Ocean, under conditions described as ‘baseline’. This baseline air is representative of a large area of the Southern Hemisphere, unaffected by regional pollution sources (there are no nearby cities or industry that would contaminate the air quality).

Fig. 1:  Cape Grim Baseline Air Pollution Station (looking almost directly south)

Fig. 2:  CO2 concentration, Cape Grim.

Fig. 3:  Methane concentration, Cape Grim.

Fig. 4:  Nitrous oxide concentration, Cape Grim.

There is no doubt that concentrations of greenhouse gases have been increasing.  We should therefore expect to see some increase in downwelling longwave radiation.

Downwelling IR data are available from the Bureau of Meteorology which maintains a database of monthly 1 minute solar data from a network of stations around Australia, including Cape Grim.

What better location than Cape Grim to study the effects of greenhouse gas concentrations from month to month on readings of downwelling IR.  The instruments are within metres of each other under “baseline” conditions at a pristine site.

The data include 1 minute terrestrial irradiance (i.e. downwelling IR striking a horizontal surface) from which I calculated mean daily IR for each month.  To remove the seasonal signal, I calculate anomalies from monthly means.

Fig. 5:  Downwelling longwave radiation anomalies, Cape Grim.

Oops! IR has been decreasing for the full length of the record, 20 years (May 1998 to June 2018).   And monthly IR anomalies plotted against monthly CO2 anomalies show a similar story:

Fig. 6:  Downwelling longwave radiation anomalies, Cape Grim.

In the most suitable location in Australia, from May 1998 to June 2018 there has been no increase in downwelling infra-red radiation, despite an increase of 41.556 ppm atmospheric concentration of carbon dioxide, 104.15 ppb of methane, and 14.472 ppb of nitrous oxide.

So what factors do influence downwelling IR and thus surface warming or cooling?  Together with solar radiation, that other greenhouse gas, H2O.  Gaseous H2O (humidity) and clouds formed of liquid and ice H2O are by far the major players in returning heat to the surface.

We see this in a plot of downwelling IR against cloudiness (from nearby Marrawa).

Fig. 7:  Downwelling IR anomalies vs Cloudiness, Cape Grim.

Daytime cloudiness (an average of observations at 9.00 a.m. and 3.00 p.m.) increases downwelling IR.  We have no data for night time cloudiness unfortunately.

To illustrate the irrelevance of carbon dioxide, here is a plot of anomalies of solar radiation (global irradiance), downwelling infra-red radiation, daytime cloudiness, and carbon dioxide concentration at Cape Grim over the past 20 years.

Fig. 8:  Anomalies of IR, Global Irradiance, CO2, and Daytime Cloud at Cape Grim 1998-2018

And zooming in on 2008 to 2010:

Fig. 9:  Anomalies of IR, Global Irradiance, CO2, and Daytime Cloud at Cape Grim 2008-2010

There is a feedback mechanism: cloudiness inhibits daytime temperature and increases IR and nighttime temperature; decreased cloudiness means decreased IR; but less cloud and higher daytime temperature will increase IR as well if sustained; and higher IR also increases daytime temperature.  Further, sustained decrease in global radiation due to increased cloud cools the surface, thus decreasing IR.

Carbon dioxide concentration changes have no detectable effect.

A desert location, where humidity is typically very low and rain and cloudiness very infrequent, would also be ideal for checking on downwelling IR from carbon dioxide.  Alice Springs in the central desert is such a location with available irradiance data.

At Alice Springs as well, since March 1995 downwelling IR has been decreasing.

Fig. 10:  Downwelling longwave radiation anomalies, Alice Springs.

The relationship between cloud and IR is even more evident.

Fig. 11:  Anomalies of IR, Global Irradiance, CO2, and Daytime Cloud at Alice Springs 2008-2010

Fig. 12:  Downwelling IR anomalies vs Cloudiness, Alice Springs.

Cloudiness has an even greater influence on IR in desert than maritime locations.

TAKE AWAY FACT:-  For over 20 years, at what are arguably the most suitable sites in Australia, increasing greenhouse gas concentrations have had no detectable effect on downwelling longwave radiation.  Natural factors including cloudiness changes have vastly overwhelmed any such effect and have instead led to a decrease in downwelling longwave radiation.

That is indeed a most inconvenient pause.

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To replicate these findings:

Go to http://reg.bom.gov.au/climate/reg/oneminsolar/index.shtml

You will need to register with a username and password.  Then click on an irradiance observation station.  Select year and month.  Download the zip file, and open in your preferred application.  (I use Excel).  IR data are in Column W- the values are wattminutes of IR striking a horizontal surface of area one square metre.

My method:  Order the data in ascending order to remove null values.  Count the minutes of valid data and calculate the percentage valid of all possible minutes in that month.  (I discard months with less than 80% valid data.)   Divide the total minutes by 1,440 to convert to days.  Sum the valid data and divide by 60,000 to find kilowatthours; divide by the number of days to find the mean daily value; then multiply by 3.6 to convert to Megajoules.  Plot monthly values against time or carbon dioxide concentration.

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The Pause Update July 2017

The complete UAH v6.0 data for July 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, Australia, and the Southern Hemisphere, except for Southern Extra-Tropics, South Temperate, and South Polar. The 12 month mean to July 2017 for the Globe is +0.35 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 eight months long- 464 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 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

The Pause has ended. A trend of +0.53C/100 years (+/- 0.1C) since February 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:

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended but temperatures for the last 19 years are rising very slowly.

Tropics:

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +0.52C/ 100 years.

Northern Extra Tropics:

The Pause has ended and the trend is increasing, but the slowdown since 1998 is obvious.

Northern Temperate Region:

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

Southern Extra Tropics:

The Pause has weakened but still just persists, and 12 month means have peaked.

Southern Temperate Region:

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause likewise persists but has shortened.

Northern Polar:

The trend has increased and will continue to do so even though 12 month means are falling rapidly.  The strong trend in Arctic temperatures is due to a step change from 1995 – 2002, and the strong 2015 – 2016 El Nino.

Southern Polar:

The South Polar region has been cooling (-0.12C) for the entire record. Although the 12 month means may have peaked, this cooling trend will slow over the next few months, and Global Warming Enthusiasts may start to get excited.

USA 49 States:

The warming trend is increasing.

USA 48 States:

Excluding Alaska the USA has only +0.23C/ 100 years warming.  This trend will increase however.

Australia:

The Pause has ended, but the trend since June 1998 has reduced from +0.42C/ 100 years to +0.3C, and since September 2002 is +0.13C.

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

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, and the Pause is likely to disappear from all southern regions except South Polar in the next couple of months.

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

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:

For 19 years “global” warming has been dominated by the influence of the Tropics and North Polar regions.

The imbalance between the two hemispheres is obvious.

The Pause has disappeared from the USA, Australia, and the Southern Hemisphere, but not the Southern Extra-Tropics, South Temperate, and South Polar regions.  Interestingly, July anomalies have decreased in Northern regions but increased in Southern regions and the Tropics.  The next few months will be interesting.

The Pause Update: June 2017

Better late than never!  I’m sorry for the lateness of this post.  A couple of issues and events got in the way.

The complete UAH v6.0 data for June 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, Australia, and the Southern Hemisphere, except for Southern Extra-Tropics, South Temperate, and South Polar. The 12 month mean to June 2017 for the Globe is +0.36 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 seven months long- 463 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 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

The Pause has ended. A trend of +0.49 C/100 years (+/- 0.1C) since February 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:

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended but temperatures for the last 19 years are rising very slowly.

Tropics:

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +0.49C/ 100 years. 12 month means are dropping fast.

Northern Extra Tropics:

Northern Temperate Region:

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

Southern Extra Tropics:

The Pause has weakened and shortened but still persists, and 12 month means have peaked.

Southern Temperate Region:

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause likewise persists.

Northern Polar:

The trend has increased and will continue to do so even though 12 month means are falling rapidly.  The strong trend in Arctic temperatures is due to a step change from 1995 – 2002, and the strong 2015 – 2016 El Nino.

Southern Polar:

The South Polar region has been cooling (-0.14C) for the entire record. Although the 12 month means may have peaked, this cooling trend will slow over the next few months, and Global Warming Enthusiasts may start to get excited.

USA 49 States:

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

Australia:

The Pause has ended suddenly, and will not re-appear for some time.

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

The Pause has disappeared from Australia.

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:

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:

For 19 years “global” warming has been dominated by the influence of the Tropics and North Polar regions.

The imbalance between the two hemispheres is obvious.

The Pause has disappeared from the USA, Australia, and the Southern Hemisphere, but not the Southern Extra-Tropics, South Temperate, and South Polar regions. El Nino tropical heat is rapidly decreasing, with all means falling. The next few months will be interesting.

The Pause Update: May 2017

The complete UAH v6.0 data for May 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 May 2017 for the Globe is +0.35 C – down 0.01C from April.

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 six months long- 462 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 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

The Pause has ended. A trend of +0.46 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:

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended but temperatures for the last 19 years are rising very slowly.

Tropics:

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +0.47C/ 100 years. 12 month means are dropping fast.

Northern Extra Tropics:

Northern Temperate Region:

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

Southern Extra Tropics:

The Pause has weakened but still persists, and 12 month means have peaked.

Southern Temperate Region:

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause likewise persists.

Northern Polar:

The trend has increased rapidly and will continue to do so even though 12 month means have started to fall.  The horizontal black lines show the pause for the first 16 years, and the pause from 2003 – 2015.  The strong trend in Arctic temperatures is due to a step change from 1995 – 2002, and the strong 2015 – 2016 El Nino.

Southern Polar:

The South Polar region has been cooling (-0.14C) for the entire record. Although the 12 month means may have peaked, this cooling trend will slow over the next few months, and Global Warming Enthusiasts may start to get excited.

USA 49 States:

The Pause has ended. It will not re-appear for some time.  And by the way, that is almost entirely due to Alaska: here’s the plot without Alaska:

Paused!  But that could disappear as well.

Australia:

The Pause has shortened dramatically, but is still 19 years 9 months- over half the record.   And the trend since September 1995, two years longer, is less than +0.2C.

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

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:

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:

For 19 years “global” warming has been dominated by the influence of the Tropics and North Polar regions.

The imbalance between the two hemispheres is obvious.

The lower troposphere over Australia has been strongly cooling for those 19 years- over 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 means falling. The next few months will be interesting.

The Pause Update: April 2017

The complete UAH v6.0 data for April have finally 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 April 2017 for the Globe is +0.36 C and continuing steadily downwards.

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 five months long- 461 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 March 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

The Pause has ended. A trend of +0.44 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:

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended but temperatures for the last 19 years are rising very slowly.

Tropics:

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +0.45C/ 100 years. 12 month means are dropping fast.

Northern Extra Tropics:

Northern Temperate Region:

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

Southern Extra Tropics:

The Pause has weakened and shortened but still persists, and 12 month means have peaked.

Southern Temperate Region:

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause likewise persists.

Northern Polar:

The trend has increased rapidly and will continue to do so even though 12 month means have started to fall.  There is an argument for saying that no recent pause is visible, but there was one for the first 16 years.

Southern Polar:

The South Polar region has been cooling (-0.16C) for the entire record. Although the 12 month means may have peaked, this cooling trend will slow over the next few months.

USA 49 States:

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

Australia:

The Pause is still 21 years 2 months- well over half the record.

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

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:

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:

The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for 18 years and 11 months- over 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 means falling. The next few months will be interesting.

The Pause Update: March 2017

The complete UAH v6.0 data for March 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 March 2017 for the Globe is +0.40 C- down 0.12 C in four months.

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 four months long- 460 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 March 2017.
[CLICK ON IMAGES TO ENLARGE]

Globe:

The Pause has ended. A trend of +0.41 C/100 years (+/- 0.1C) since February 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:

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended but temperatures for the last 19 years are rising very slowly.

Tropics:

The Pause in the Tropics (20N to 20S) has ended and the minimal trend is now +0.43C/ 100 years. 12 month means are dropping fast.

Northern Extra Tropics:

Northern Temperate Region:

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

Southern Extra Tropics:

The Pause has weakened and shortened but still persists.

Southern Temperate Region:

Using estimates calculated from South Polar and Southern Extra-Tropics data, the Pause likewise persists.

Northern Polar:

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

Southern Polar:

The South Polar region has been cooling (-0.17C) for the entire record. With 12 month means still rising, this cooling trend will slow over the next few months.

USA 49 States:

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

Australia:

The Pause is still 21 years 5 months- well over half the record.

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

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:

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:

The imbalance between the two hemispheres is obvious. The lower troposphere over Australia has been strongly cooling for 18 years and 10 months- over 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 means except the South Polar region falling. The next few months will be interesting.

 

The Pause Update: February 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:

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:

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended- just.

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:

Northern Temperate Region:

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

Southern Extra Tropics:

The Pause has weakened and may soon disappear.

Southern Temperate Region:

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

Northern Polar:

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

Southern Polar:

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:

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

Australia:

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:

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:

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:

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

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:

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:

That’s since December 1997.

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

The Pause has ended- just.

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:

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

Northern Temperate Region:

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:

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

Southern Temperate Region:

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

Northern Polar:

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

Southern Polar:

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:

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

Australia:

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:

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:

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:

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

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)

 

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

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.

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

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

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.

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.

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

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.

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.

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

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

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:

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:

That’s since December 1997.

Northern Hemisphere:

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

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

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:

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

Southern Extra Tropics:

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

Northern Polar:

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

Southern Polar:

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

USA 49 States:

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

Australia:

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:

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:

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:

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.