Friday, April 27, 2007

Outback south australia

Continuing on with south Australia, we head out bush to look at two stations in the middle of whoop whoop, namely, Yongala and Woomera Aerodrome.

whilst Woomera might seem outback, it has the largest military testing area in the world (around the same size as England), where all sorts of weapons and aerospace testing is done (including nuclear weapons in the past).

But onto the data. Maximum and minimum data go back as far as 1925, whilst time related temperatures go back to the mid 50s or 60s (with the exception of midnight which is only 15 years worth).

Analysis of maximum temperatures show a significant increase in temperatures (t=3.5,p<0.01), whilst minimum temperatures show no such increase (t=1.6,p=0.1).

A significant increase was found in temperatures at 3am (t=2.2,p<0.05), Noon (t=2.3,p<0.05), 3pm (t=2.8,p<0.01) and 6pm (t=2.03,p<0.05). No significant increase was found at the remaining times (6am: t=1,p=0.3; 9am: t=0.45,p=0.65; 9pm: t=1.9,p=0.06).

It is no surprise to see that when maximum temperatures increased, so to times at noon, 3pm and 6pm. The increase in temperature at 3am however is very surprising, especially when considering that times around this were insignificant.

So in outback south Australia, it seems as though we are only heating up during the day, moreso when the sun is at it's hottest. There was no significant change in rainfall since the start of the 20th century.


Phil_B said...

Correct me if I am wrong, but I don't recall you finding the 3am warming in any other station data.

Looking at the data, the warming trend seems to be weak. Just noise?

Jonathan Lowe said...

no you are right Phill, the fact that no significant increase was found on temperatures either side of this suggests that it could be a testing error. 2% significance level indicates that we will get these of course from time to time.

George said...

I am puzzled by your statements that because the most amount of warming is occuring during the day then its the sun that is doing that. Isn't the atmosphere more complex than that. Is not the trapping of longwave radiation more of an effect than direct short wave radiation?

Jonathan Lowe said...

If Human induced global warming was cause due to increases in CO2 levels, then we would see an increase in temperature at all times of the day. Unfort. at the moment in my analysis we are not seeing this.