Friday, November 03, 2006

I hate cold mornings

Well the last few days we’ve concluded that Australia’s mean monthly maximum temperatures are increasing of late, but nothing significantly different from the norm. The mean monthly temperatures more than 100 years ago were greater than now. On the counter side we also showed that mean monthly minimum temperatures have increased of late. We have seen an increase of 0.27 degrees C in the last 30 years. However it looks as though this increase has not continued to increase in the last 30 years and has remained relatively constant. The reason for this increase in 0.27 degrees at around the mid 1970s mark, is undetermined.

However it makes a lot of sense to take measurements at a certain time and compare them. By keeping the time constant we can see if 6pm 50 years ago was colder than 6pm now, or whether 9am 100 years ago was hotter or colder than it is today. If global warming is happening in Australia, and the place is hotting up, then we would expect, especially in the last 20-50 years a significant increase in this variable.

So shall we test it out? The next 8 days, yep the next 8, will be an article each day looking at the variation in temperatures at certain times of the day. These times are: Midnight, 3am, 6am, 9am, noon, 3pm, 6pm and 9pm. A fairly broad range obviously.

ABMs data has taken measurements at these times from ages back. 9am and 3pm temperatures were recorded from when temperature recordings first started (mid 1800s), 9pm recordings started from about 1890 and all other temperatures were unfortunately only recorded from as late as 1940. Nevertheless, we shall analyse them all.

And what better way to start, than the times with the most data: 9am and 3pm. Lets check the earlier time to start off with.

On the left is a graph of Australia’s deviation from the average of temperatures recorded from all over Australia at 9am in the morning. Times are obviously adjusted for day light savings. And what can we conclude from this? It seems that the times between 1860 all the way up to 1940 recorded on average greater than normal temperatures. Then we had 25 years of really cold start work times, followed by a period of 25 years of slightly warmer wake up calls, another 25 years of chilling turn the electric blanket on temperatures, and apart from last year, we had 4 years in a row of temperatures about 0.2 degrees greater than norm at 9am in the morning.

Now I’m pretty sure that I don’t have to do a statistical test of this analysis to prove scientifically if there has been a statistically significant increase or decrease in temperature. I won’t bother. We all know the result from looking at the graph. We’ve had a bit of cold, a bit of warmth, a bit of cold, a bit of warmth. The pattern seems even cyclic if anything. But either way, what we are witnessing here, is proof that Australia’s temperatures, at least at 9am in the morning, have not increased at all. Global warming, and human induced CO2 levels, have no influence whatsoever on the temperature at this stage of the morning.

Which to be honest, is a little upsetting. I hate cold mornings.

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