Archive for April, 2017

The Pause Update: March 2017

April 15, 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:

Pause Mar 17 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:

Pause Mar 17 globe monthly

Northern Hemisphere:

Pause Mar 17 NH

The Northern Hemisphere Pause has well and truly ended.

Southern Hemisphere:

Pause Mar 17 SH

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

Tropics:

Pause Mar 17 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:

Pause Mar 17 NExT

Northern Temperate Region:

Pause Mar 17 NTemp

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

Southern Extra Tropics:

Pause Mar 17 SExT

The Pause has weakened and shortened but still persists.

Southern Temperate Region:

Pause Mar 17 STemp

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

Northern Polar:

Pause Mar 17 N polar

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

Southern Polar:

Pause Mar 17 S 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:

Pause Mar 17 USA49

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

Australia:

Pause Mar 17 Oz

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:

Pause Mar 17 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:

Pause Mar 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:

Pause Mar 17 Trends 98

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.