Sunday, January 28, 2007

Tennant Creeks Beaches

The only other non urban weather station situated in the Northern Territory that has data going back to at last 1970 is at Tennant Creek. In fact this station was set up in late 1969 providing all relevant temperature data from then with the exception of Midnight which started at 1990. I once traveled out to Tennant Creek and chatted to a local at the bar. He said:

“Do you know what the best thing is about Tennant Creek?”

I replied “No”

He said “The beaches”

Tennant Creek is located almost smack bang in the middle of Australia. He replied to my look of confusion “they are all the same distance, take your pick”

There’s not a lot to do there you see. Anyway, back to science, analysis of maximum data at Tennant Creek shows no significant increase or decrease in temperatures (t = 0.4, p = 1.12). However a significant increase was found in minimum temperatures (t = 2.3, p = 0.027). Interestingly both sets of data had large negative temperatures between 1974 and 1978 which is also in line with the Alice Springs observations.

Lets have a look at the temperature data at certain times of the day. Temperatures at Midnight only have several years, so unless there is a large trend, which there wasn’t, it is not surprising to see no significant increase or decrease (t = -0.8, p = 0.45). Similarly temperatures at 3am and 6am showed no significant temperature trends (3am: t = 1.28, p = 0.2; 6am: t = 1.44, p = 0.16).

Surprisingly however we did find a significant increase in temperature when the sun rose at 9am (t = 3.62, p < 0.01). This is surprising as we found no significant difference in maximum temperatures. It was also strange that despite an increase in minimum temperatures no difference was found at the times most likely to induce a minimum temperature (3am to 6am). Temperatures at Noon (t = 1.9, p = 0.07), 3pm (t = 1.4, p = 0.17), 6pm (t = 0.16, p = 0.87) and 9pm (t = 0.51, p = 0.61) showed no significant temperature trends.

So similar to Alice Springs, the most notable increase in temperature occurred at 9am. As it was the only significant increase, Tennant Creek had not been heating up as much during the day as Alice Springs. The significant minimum temperature increase and no significant increases at night is quite bizarre, but for me this proves that working with temperatures at times that are kept constant is more accurate than working on simply maximum and minimum temperatures.

If only Tennant Creek had a beach. That would stabilise the temperature!

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