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John's blog posts are hosted at:http://jgc.org/blog/
Well, I was right about one thing
December 18 2009
Just received a nice mail from the Met Office in response to my queries about the data showing that I was right about one thing: there is something odd about the values in Australasia (or as they say, Oceania).I had written to them saying:I've noticed that there seems to be… read moreAdjusting for coverage bias and smoothing the Met Office data
December 18 2009
As I've worked through Uncertainty estimates in regional and global observed temperature changes: a new dataset from 1850 to reproduce the work done by the Met Office I've come up against something I don't understand. I've written to the Met Office about it, but until I get a reply this… read moreDecember 17 2009
A few days ago I moaned about an inaccurate and ininterpretable visualization appearing in a book touting its own excellence at visualization. Now, I'm pointed to a visualization of the recently released Met Office land surface temperature record that makes similar mistakes.Folks, data visualization isn't about pretty colours, or slapping… read moreAn open source project for my Met Office data analyzer
December 14 2009
Since some other people have been playing with my little Perl program to analyze the Met Office land surface temperature data, I've registered a project at SourceForge so that others can work with me on it.I've also imported my latest version of the script which outputs data about the number… read moreOne more thing about the Met Office Land Surface Temperature data
December 14 2009
If you've been following my posts you might have spotted an oddity: if you run the animation of gridding since 1850 it's pretty clear that there weren't many stations going into the mix up until the 1950s.This introduces uncertainty when calculating the hemisphere and global figures. To get an idea… read moreMet Office Land Surface Temperature Data: The Video
December 12 2009
If you don't have all the time to follow all my blog posts on messing with the Met Office data, I've made you a 9 minute YouTube that gives you the highlights... read moreSource code for processing the Met Office Land Surface Temperature data
December 10 2009
The source code used to validate the Met Office data and produce all the visualizations on this blog is here. Enjoy!This code does the following:1. Reads and validates the Met Office Land Surface Temperature data file.2. Spits out errors if it finds problems with the data.3. Produces a Google Maps/Google… read moreThere's something seriously odd about "NAPIER NELSON PK"
December 10 2009
If you are messing with the Met Office temperature data there's one file which is really odd: 93/933710. It has temperature data for NAPIER NELSON PK at (-39.5, -176.8) There is actually a Napier Nelson Park in New Zealand but not quite at those coordinates. And I can't find a… read moreReconstruction of the 1850 to present day warming trend from Met Office data
December 10 2009
Having got the gridding working of the recently released Met Office Land Surface Temperature data it was a short step to reconstruct the temperature trends for 1850 to the present day.I've performed the same gridding as the HadCRUT3 dataset with one exception: I have not removed outliers (the papers on… read moreA first look at gridded data from the Met Office Land Surface Temperature Record
December 08 2009
Well, I've got it working and here's a KML file for you to explore in Google Earth. When I say 'it' I mean:1. Extract the data from the Met Office files2. Check the Normals3. Calculate anomaly data for all stations4. Grid data onto 5 degree square portions of globe using… read moreProblems to watch for in the Met Office Land Surface Temperature Data
December 08 2009
As I've been working through verifying the integrity of this data I've noticed a number of problems/gotchas that you'll need to watch for. These have come up while verifying the 'Normals' data which should be the monthly average data for 1961 to 1990 where there's data and at least 15… read moreGoogle Earth view of Met Office Land Surface Temperature Data
December 08 2009
The UK Met Office has released a subset of the HadCRUT data that contains temperature observations from 1729 stations around the world. To get started with this data you need to go here.I downloaded the data and wrote a program to verify its integrity (looks ok so far) and then… read moreDecember 04 2009
Yesterday I received an email from Facebook that I assumed was some sort of scam. In fact, it was totally genuine and I received it because someone I know is using Facebook to promote their business.Here's the email: I know three of those people, but the three people in the… read moreWhoops. There's a third bug in that code.
December 03 2009
So, I'm sitting on the bus this morning executing CRU's IDL code in my head when I suddenly realized that there's another more subtle bug in the exact same code I was looking at the other day.Here's the critical loop once more: for i=0.0,nel do begin x=cos(a)*(xkm/110.0)*(1.0/cos(!pi*pts1(i,0)/180.0))+pts1(i,1) x=x(-179.9) y=sin(a)*(xkm/110.0)+pts1(i,0) y=y>(-89.9)… read moreWe should probably feel sorry for Ian 'Harry' Harris at CRU
December 01 2009
Reading through the code and then through his HARRY_READ_ME.TXT you can see a man up against something that was slightly outside his ability. I don't mean that in a nasty way; what was needed was a professional programmer and not a professional scientist.In the midst of the file we find… read moreRecent Posts | All Posts
Multimedia
Webcast: Around the world in 32 minutes with The Geek Atlas
June 24, 2009
Duration: Approximately 60 minutes. Cost: Free In this webcast, author John Graham-Cumming presents a tour of 32 places from his book, The Geek Atlas, in 32 minutes. From Jaipur to Hawaii, via Spain, Paris, London, New York and beyond, The Geek Atlas...
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