Monday, 21 April 2008


Starting to get a following!! Please leave a blog address or web address so I can return the comments. Okay results time, in an earlier post I was talking about the experiment I was conducting in a local cave system, attempting to forecast the weather by underground pressure changes. This is part 2:

So I decided on three different types of data, one set called real time, this was the data down loaded from loggers as is, the second set introduced a 1 day lap within the time data and the third set introduced a 5 hour time lag. With me so far. Okay to work out how significant these results were I used a statistical test called Pearson's correlation co-efficient, so thanks Mr Pearson. Now what this does, it take the two data sets, so in this case, one data set was from Bristol Airport and the other set was from Goughs cave and it compares them, not sure how, but it does. And it provides a number or more a formula which can be graphical represented on a graph, the formula details the slope of the curve. It also gives an R square value, which is the important bit because that shows how close to each other the results are.

For the real time data I got an R squared value of 0.5949, you may remember if you read the last post, that the closer the R squared value is to 1 the better, so that's not bad. I ran the same test on the 1 day lag, so the data had one day removed and got an R squared value of 0.6438, getting better. So I ran the test with a 5 hour lag introduced and the R Square value was 0.8888 which is pretty dam good.

So what this means, is its not possible to forecast the weather by underground pressure changes, which is a shame because that would of been cool. Putting it into easy terms so I can understand it, as pressure rises at Bristol Airport, pressure will also rise at Goughs cave only 5 hours later...hence a 5 hour delay exists. Pretty neat.

So what next, well as of today I have a month to write the experiment up, get it printed and ready for submission, also I have to write an essay called Psychogeography in a Heritage town...which could be interesting and then I have an exam on Paloclimate....don't even go there!! Then the summer starts, and of course there is the small matter of graduating, getting up in front of my peers and collecting my 2:2 we can't all be really, really smart you know.

1 comment:

Monica said...

You will be fine (two slaps on your back)! You are very clever as someone told you today! I keep telling you every day!