Posts Tagged ‘proposition 04’

Proposition 04: False

Tuesday, January 5th, 2010

Well, the final GSOD readings for 2009 have now been released. Time to finish this off…

rmw42@pandora:~/NOAA$ ./average 2009
rmw42@pandora:~/NOAA$ cat Average-* | sort > Averages.txt
rmw42@pandora:~/NOAA$ cat Averages.txt | ./warm5-2009
1484 stations had 2009 as one of their 5 warmest years
4187 stations did not have 2009 as of their 5 warmest years
11746 stations rejected for having insufficient data

Only 26% of the weather stations have 2009 anywhere in their top 5 – I guess that’s a reason for the Met Office not to count their climate chickens too early, as December was brutally cold and pushed the year out of the record books.

Proposition 04: Chillin’

Monday, December 14th, 2009

Still only provisional results. The previous results were from the 2009 GSOD data to December 3rd. I’ve just downloaded the data up to December 10th and re-run the code:

rmw42@pandora:~/NOAA$ cat Averages.txt Average-2009.txt | sort | ./warm5-2009
3294 stations had 2009 as one of their 5 warmest years
2303 stations did not have 2009 as of their 5 warmest years
11767 stations rejected for having insufficient data

So,¬†adding a week¬†of cold December temperatures, the split has gone from 3665:1906 (66%:34%) to 3294:2303 (59%:41%). Still well in favour of 2009 being a very hot year, but another three weeks of cold might tip the balance…

Proposition 04: Possibly True

Wednesday, December 9th, 2009

Not going to confirm this one yet, as there are are ~4 weeks’ more readings still to come – in the coldest part of the year in the Northern Hemisphere – which I expect will drag the annual mean temperature down somewhat.

However, using the data to the first week of December, we get:

rmw42@pandora:~/NOAA$ cat Averages.txt Average-2009.txt | sort | ./warm5-2009
3665 stations had 2009 as one of their 5 warmest years
1906 stations did not have 2009 as of their 5 warmest years
11771 stations rejected for having insufficient data

which shows the proposition to be true in 66% (i.e. near enough two thirds) of stations for now, though if the December average is something like 10F colder than the summer this could change substantially.

It also shows a potential flaw in my “>=90% of days” check – a year can miss out almost an entire month and still be “OK”. That month could just as easily be July as January, and so could move temperatures up or down. I believe missing days will be somewhat randomly distributed, but this should be checked.

Propositions 03, 04, 05: Hot decade

Wednesday, December 9th, 2009

Today’s Metro article “China lambasts US and EU emission pledges” by Jo Steele contains a barrage of claims:

Meanwhile, the Noughties have been the warmest decade on record and this year has been one of the five hottest, weather experts warned.

While 1998 remains the hottest single year since records began in 1850, the last ten years have been the warmest, the Met Office revealed.

Wow. It ends with what looks like a repeat of (false) Proposition 02, but the others can stand a bit of scrutiny.

Proposition 03:

The Noughties have been the warmest decade on record

Proposition 04:

This year [2009] has been one of the five hottest [years on record]

Proposition 05:

1998 remains the hottest single year since records began

Methodology:

Well, propositions 04 and 05 seem fairly straightforward – top 1 and top 5s to go with the top 10 analysis already done. A bit of Perl hacking should get results for those today, though since we’re still in 2009 the final result will have to wait until January. Proposition 03 will take a bit more work, but not much – do we consider rolling decades or bucket the temperature record by (year/10)? Rolling decades is probably the more general version, but both are interesting tests to run.

So, time to get cracking!