Archive for February, 2019

Australia’s Record Hot January: Mostly Weather, Not Climate Change

Monday, February 4th, 2019

The Australian Bureau of Meteorology (BOM) claims January, 2019 was record-hot. There is no doubt it was very hot — but just how hot… and why?

The BOM announcement mentions “record” no less than 28 times… but nowhere (that I can find) in the report does it say just how long the historical record is. My understanding is that it is since 1910. So, of course, we have no idea what previous centuries might have shown for unusually hot summers.

The assumption is, of course, that anthropogenic global warming is to blame. But there is too much blaming of humans going on out there these days, when we know that natural weather fluctuations also cause record high (and low) temperatures, rainfall, etc.

But how is one to know what records are due to the human-component of global warming versus Mother Nature? (Even the UN IPCC admits some of the warming since the 1950s could be natural. Certainly, the warming from the Little Ice Age until 1940 was mostly natural.)

One characteristic of global warming is that it is (as the name implies) global — or nearly so (maybe not over Antarctica). In contrast, natural weather variations are regional, tied to natural variations and movements in atmospheric circulation systems.

That “weather” was strongly involved in the hot Australian January can be seen by the cooler than normal temperatures in coastal areas centered near Townsville in the northeast, and Perth in the southwest:

The extreme heat was caused by sinking air, which caused clear skies and record-low rainfall in some areas.

But why was the air sinking? It was being forced to sink by rising air in precipitation systems off-shore. All rising air must be exactly matched by an equal amount of sinking air, and places like Australia and the Sahara are naturally preferred for this — thus the arid and semi-arid environment. The heat originates from the latent heat release due to rain formation in those precipitation systems.

If we look at the area surrounding Australia in January, we can see just how localized the “record” warmth was. The snarky labels reflect my annoyance at people not thinking critically about the difference between ‘weather’ and ‘climate change’:


January 2019 surface temperature anomalies (deg. C, relative to the 1981-2010 average) from NOAA’s Global Forecast System (GFS) analysis fields. Unlabeled graphic courtesy of WeatherBell.com.

So, the claims of the usual suspects such as “Australia’s Extreme Heat is a Sign of Things to Come” is just one more example of the blind leading the blind.

UAH Global Temperature Update for January 2019: +0.37 deg. C

Friday, February 1st, 2019

The Version 6.0 global average lower tropospheric temperature (LT) anomaly for January, 2019 was +0.37 deg. C, up from the December, 2018 value of +0.25 deg. C:


Global area-averaged lower tropospheric temperature anomalies (departures from 30-year calendar monthly means, 1981-2010). The 13-month centered average is meant to give an indication of the lower frequency variations in the data; the choice of 13 months is somewhat arbitrary… an odd number of months allows centered plotting on months with no time lag between the two plotted time series. The inclusion of two of the same calendar months on the ends of the 13 month averaging period causes no issues with interpretation because the seasonal temperature cycle has been removed, and so has the distinction between calendar months

Various regional LT departures from the 30-year (1981-2010) average for the last 13 months are:

YEAR MO GLOBE NHEM. SHEM. TROPIC USA48 ARCTIC AUST
2018 01 +0.26 +0.46 +0.06 -0.11 +0.59 +1.36 +0.43
2018 02 +0.20 +0.25 +0.16 +0.04 +0.92 +1.19 +0.18
2018 03 +0.25 +0.40 +0.10 +0.07 -0.32 -0.33 +0.60
2018 04 +0.21 +0.32 +0.11 -0.12 -0.00 +1.02 +0.69
2018 05 +0.18 +0.41 -0.05 +0.03 +1.93 +0.18 -0.39
2018 06 +0.21 +0.38 +0.04 +0.12 +1.20 +0.83 -0.55
2018 07 +0.32 +0.43 +0.22 +0.29 +0.51 +0.29 +1.37
2018 08 +0.19 +0.22 +0.17 +0.13 +0.07 +0.09 +0.26
2018 09 +0.15 +0.15 +0.14 +0.24 +0.88 +0.21 +0.19
2018 10 +0.22 +0.31 +0.13 +0.34 +0.25 +1.11 +0.39
2018 11 +0.28 +0.27 +0.30 +0.50 -1.13 +0.69 +0.53
2018 12 +0.25 +0.32 +0.19 +0.32 +0.20 +0.65 +1.19
2019 01 +0.37 +0.32 +0.42 +0.37 +0.48 -0.18 +1.10

The linear temperature trend of the global average lower tropospheric temperature anomalies from January 1979 through January 2019 remains at +0.13 C/decade.

The UAH LT global anomaly image for January, 2019 should be available in the next few days here.

The new Version 6 files should also be updated at that time, and are located here:

Lower Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tlt/uahncdc_lt_6.0.txt
Mid-Troposphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tmt/uahncdc_mt_6.0.txt
Tropopause: http://vortex.nsstc.uah.edu/data/msu/v6.0/ttp/uahncdc_tp_6.0.txt
Lower Stratosphere: http://vortex.nsstc.uah.edu/data/msu/v6.0/tls/uahncdc_ls_6.0.txt