Not only has siting of weather stations near urban heat sources have been a real issue for weather measurement stations worldwide, but so maybe has the recently implemented automatic electronic weather measurement instrumentation.
Reports are appearing that the new automatic system may be producing exaggerated temperature readings. For example this may be the case in Germany: read here and here.
Now we find another example, this one coming from the Alice Springs, Australia station.
According to the Australian ABC news site, the new electronic thermometer measured a scorching 46°C (an all time high) last Tuesday. However an adjacent mercury thermometer showed only 41.5°C, i.e. a huge 4.5°C less! It turns out that the 46°C reading was a “spike” that lasted only a minute before disappearing.
As a consequence, the ABC writes, the “Bureau of Meteorology (BoM) has withdrawn its advice Alice Springs recorded its hottest day on Tuesday, blaming a faulty thermometer for an incorrect temperature reading.”
The old record of 45.2°C was set 55 years ago, in 1960. The ABC quotes climatologist Joel Lisonbee:
It looks like we had an instrument fault with our automatic weather station at the Alice Springs Airport. […] We have some mercury and glass thermometers that did not show that spike to 46C. […]
They showed the maximum temperature yesterday to be only 41.5C.”
According to the ABC, the station is located right next to a “scorching” airport tarmac. So how could the new automatic thermometer produce such a faulty reading?
It seems that these new automatic systems are highly sensitive. As reported here at NTZ, one German weather instrumentation expert conducted an 8.5 year side-by-side comparison test of the new automatic electronic temperature measurement system and the former mercury glass thermometer. That test showed that the new automatic thermometers produced a mean temperature for the period that was a whopping 0.9°C warmer than the mercury thermometer. That result could possibly in part explain why Germany’s annual mean temperature jumped by a similar amount from 1985 to 2000, i.e. the period that Germany transitioned over to automatic measurement.
The Alice Springs inflated reading is an indication that the new measurement system indeed may be overstating temperature readings all over the world, thus adding uncertainties on top of those created by the urban heat island effect.
With the Alice Springs Station, the error was caught and the “record high” was withdrawn. Yet the question remains if this is the case all over the world. How many recent records are in fact not records at all, but rather are merely faulty readings produced from instrumentation and siting issues?
10 responses to “Alice Springs Automatic Weather Station Inflated Temperature By 4.5°C, Producing False “Record High”!”
Here’s a picture of the new weather station at Alice Springs Airport.
Tallbloke hosted an article by Roger Andrews a couple of years ago on the station relocations. Turn out that “Airport” wasn’t continuous either, moving site in the 1970’s. One of the commenters on Talkbloke’s blog spotted the step change.
Regardless of the accuracy, an electronic thermometer will not have the inherent “damping” of a traditional alcohol or mercury device. So they will always give a different result. This sounds much the same as new “Smart Meters” for electricity supplies, which can respond fast enough to charge extra for motor start-up loads, that old fashioned rotary meters can’t…
Perhaps a nice example of the difference between bias and error. Error terms should sum up to zero. These spikes do not because the maximum is always set to equal the highest value, whereas they cannot be compensated by low values. Similarly, a minimum can be biased by extremely low values. Interesting issue. I once tried to estimate the temperature record by using (computationally more time consuming) medians in stead of means, being less sentive to outliers. The whole rise of temperatures in the late twentieth century disappeared as snow under the sun.
They probably ‘noticed the error’ because the BoM is facing an investigation into their adjustments to temperature readings, which turn many flat trends into rising ones.
For more details try http://pindanpost.com/tag/kenskingdom/
Some good reading.
weird to me..the point is always the same nobody knows exactly what a station measures, so if you want to compare with historical data you don’t have to change anything.
Interesting to compare the ABC’s matter-of-fact correction with the breathless original headline:
“Alice Springs records its hottest day ever, mercury smashes 55-year record”
Note the headline implying it was a mercury thermometer that recorded the record.
Sorry for the long url address, but here’s the Google cache
Melbourne changes monitoring site from city to park, new max temperature averages 1.2C cooler
Mr Trewin also noted that the Bureau had recently changed its Melbourne monitoring site from the Royal Society of Victoria on La Trobe Street in the city to Olympic Park, near Rod Laver Arena. Maximum temperatures recorded at the new site were on average 1.2 degrees cooler, particularly on cool days, because air coming from the south and west was travelling over parklands rather than the through the city.
Cooler summer days have led to plenty of tomatoes at the Alice Springs community garden.
“I am currently picking these gorgeous tomatoes,” she said.
“We’ve been really lucky with the weather.
“When it gets too hot the flowers don’t actually produce any fruit.
“We have got more tomatoes than we can actually eat,” she said.
The BoM has had too many failures in their rush of alarmist press releases. Dr Jennifer Marohasy writes to the new Parliamentary Secretary
for the Minister to Environment, with particular responsibilities for the
Bureau of Meteorology. http://jennifermarohasy.com/wp-content/uploads/2014/03/Let-Bob-Baldwin-Re-New-Panel-18-January-1015-F.pdf via Quadrant On-line.
I sent you an e mail to firstname.lastname@example.org with a query to and also my letter to the Royal Society.Did you recieve it ok?