Friday, September 07, 2007

Station #1: Halls Creek (2012)

Halls Creek Airport, located in north west Western Australia is our first non urban weather station that has good data for all times but one going back past 1960. Weather times at 9pm are unfortunately non existent for this area.

Maximum temperatures for Halls Creek show no significant increase or decrease, however minimum temperatures show a significant increase (t=3.24,p<0.01).

Temperatures at Midnight, 3am and 6am show no significant increase in temperature, which once again suggests that the minimum temperature is no good as measuring overnight temperatures. 9am shows no significant increase either, however since 1974, temperatures have been on the rise. Noon, 3pm, and the very data sparse 6pm each show no significant increase in temperature.

When looking at differences in yearly anomalies between 3am,6am and Min we find that 3am temperatures are everywhere, but when just looking at differences between 6am and Min we see that the minimum temperature has increased at a greater and significant rate than at 6am (t=4.9,p<0.01).

Temperature anomalies between 9am and 6am suggest that 9am once once heating up quicker than 6am around the middle of last century and then from then till 1970 anomalies were around equal (which is what we would expect if Co2 was the major driving force of global warming;is it a surprise that this is the time when global temperatures decreased slightly?). But in the last few years temperature change at 9am has grown significantly quicker than at 6am.

So much quicker is the rise in temperature at 9am compared to 6am of late, that temperature anomalies at Noon compared to 9am have significantly decreased (p<0.01).

Halls creek indicates a few things for us.

1. Temperatures overnight are not increasing
2. Temperatures at 9am have and are significantly increasing over time in relation to 6am, which is probably the reason why we have a significant increase in the minimum temperature.

Whilst the data at Halls Creek isn't very conclusive, we might well just find similar and more precise trends in the stations to come.

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