Tuesday, January 23, 2007

No Temperature increase in central-east WA

Giles Meteorological Office is located on the far east of Western Australia on about the same latitude as Uluru. It is one of the BOM's most famed stations, largely due to it's isolation. It was initially built to provide data for the British atomic weapon tests and later the rocket trials from Woomera. Considering that there are no major weather stations around the area that have a good back history of data, we have decided to analyse this station by itself.

Our analysis will include maximum and minimum temperatures as well as temperature changes throughout the day over the years. Data goes back to 1957 for maximum and minimum temperatures, whilst you have to go back to 1978 for time related temperatures with the exception of temperatures at Midnight which only go back a fraction over 10 years.

Giles maximum temperatures over time are shown here with their minimum temperatures shown here. There was no significant increase or decrease in any of these over time (max: t = 0.81, p = 0.42, min: t = 1.37, p = 0.18).

It is understandable therefore that there should be no significant differences in temperature for any of the time related temperatures. And there wasn’t. Midnight showed no significant increase or decrease ( t = -0.02, p = 0.98) as well as for 3am (t = -1.18, p = 0.25), 6am (t = -0.54, p = 0.59), 9am (t = 1.36, p = 0.19), noon (t = -0.21, p = 0.83), 3pm (t = -0.64, p = 0.53), 6pm (t = -1.41, p = 0.17) and 9pm (t = -1.74, p = 0.09).

Interestingly most times showed decreases in temperature however none were significant at the 5% level. The large reason for this was in the years 2000-2002 which saw maximum temperatures at up to 1.5 degrees below the average and minimum temperatures at 1 degree below the average. Temperatures at 6pm and 9pm showed almost 2 degrees below the average during these years.

Maximum and minimum temperatures have been above average in the last 5 years, however this has proven insignificant.

In conclusion there is no evidence to prove that temperatures are increasing or decreasing in central-eastern Western Australia.

1 comment:

Anonymous said...

You can't see the observed global average temperature increase of 0.6 degrees C per century by analyzing the data from only one station over a period of a few decades.

You need to average over the data of many hundreds of stations to see the effects of global warming.

So, this is like a deaf person who din't here a significant increase in the noise levels when a plane crashed in his garden. He then concludes that nothing happened. :)