Sunday, September 11, 2011

Weatherwise and otherwise

The climate science debate seems to have cooled off but it has raised various questions on data and its accessibility. Apparently most weather data has not been digitized and in some countries in Africa and South America, data has been gathered only since the mid 20th century. India has been extremely fortunate that data collection began early with a large network of stations. It is however extremely unfortunate that this legacy of data has effectively been made useless by bureacratic procedures and a lack of a public-domain release policy on data.

One project however seems to have made good with whatever has been available and made extrapolations to fill up blanks and smoothen any bumps. WorldClim  - has made these layers available and hordes of researchers who have no better data to use make use of it.

After a day of downloading various layers for four-tiles that India straddles and merging them and formatting them, I found that it is quite educative to see how the bigger picture of temperature and precipitation looks. Here are four animated PNGs showing temperature and precipitation parameters in the region (Firefox and Chrome apparently support APNG, in case you see a static picture - its time to change your browser)
Monthly minimum temperatures

Monthly maximum temperatures
Monthly mean temperatures

Monthly precipitation

If governments could liberate satellite remote-sensing, weather and demographic/health (without personal information) data, the results could be so useful and revealing to everyone.

Worth reading
Post script
There is a bit of a lie effect in the rainfall map. The colouring scheme and bin choice makes it look like the South Asian region is a green paradise. Here is another with a slightly altered binning and colouring scheme which emphasises the drier parts.

Monthly precipitation (version 2)

Lie factor - a term introduced by Edward Tufte - More on this here, and a result of looking for the link got me to sit and read an interview with Tufte which like his books is just as interesting.

Also NASA has a number of data layer at a lower resolution. Here is a rendering of Relative Humidity using their data. You can find a number of nice animations out there as well.
Relative Humidity (%)


  1. In an ordinary world (leave alone an ideal one), the mountains of death-related data collected by "Registrar of births and deaths" has enormous public health implications among others. But, even after an RTI application, I was denied such data citing infringement of confidentiality about cause of death (even though I never asked individual data!). We are still a long way and it appears that RTI may be a great weapon in getting these things out, given the apathy for this.

  2. Even if, in the remote chance, data was made available through an RTI request, you would not be able to share it with others or make it available freely for the next 60 years (or is it 70) as all government work is copyrighted according to the Indian Copyright Act. Many government officials and even folks in scholarly institutions are under the misunderstanding that putting up something on a website for "free" download makes it "public domain".

  3. Shyamal, your observation / interpretation of the Indian Copyright Act is revealing indeed. So, when a work is under 'copyright', does it also restrict such work to be made accessible (either over the internet or otherwise) at no charge as well?

  4. @Sudhira The idea of copyrights was evolved in the era of printing and was essentially a form of supporting printers to protect their earnings. Painters and sculptors never really needed copyrights as their ability to work on a physical medium was not something that could be replicated but that changes when the medium supports duplication. Major drivers of copyright law today are therefore the music recording and movie industry. The meaning and practicality in Internet media has been questioned - for instance some consider that copyrights are violated everytime your browser downloads an image. Others have gone to court over search engines that cache images or text or generate indices or descriptors ("derivatives") to make them searchable. That is as far is practicality goes - but when it comes to legality - any work of creativity is automatically copyrighted the moment it is created. So the only way to make something non-copyrighted or "public domain" is to explicitly state so - or more formally by indicating a form of licensing. Creative Commons has been working on various of those formats so that they work across country boundaries that are meaningless on the Internet but differ widely in their legalities as regards copyright.

    Putting a copy of a copyrighted image/document on your server would technically be a copyright violation, although providing a link to it is usually not considered so. Althought technically in violation, it may not probably not be taken cognizance of, since the law runs on money and any valid case or penalty would be decided on the basis of "potential loss in revenue".

  5. @Sudhira a bit to add is that the Indian Copyright Act is based on the Crown Copyright but the US has perhaps a more democratic form of it and it has special provisions that make "most" federal works non-copyrighted.

    For more on that see:
    And for contrasts with the UK see :)

  6. @Shyamal Thanks for the detailed clarification! Then that's a bit scary part of law that prohibits posting a copyrighted material online.