Tuesday, March 19, 2013

An active viewer for Marcott et al proxies

In previous  posts I have been going through a simplified emulation of the Marcott et al Holocene temperature reconstruction. I think it will be helpful to provide an active Javascript viewer of the individual proxy data given with that paper.

I made a spaghetti plot of the linearly interpolated proxy temperature anomalies (base 4500-5500 BP) against published dates (not modified). There is a table that you can click on to make each one show up as a black curve. At the same time, the metadata from the Marcott et al SM is shown, and there is a map which shows where the proxy is from.

Update. I've made an extended viewer which lets you look at the effect of dating change, and to see a plot of just the last 2000 years.

Update. At Climate Audit, it was suggested that it would be good to be able to black two (or more) curves at once. That is easy, but it is not so easy to make clear which is which. So I've added a swap button. To compare two curves, select one, then the other, and then click swap as often as you want. The last two curves will alternate.


  1. Hi Nick, this is helpful. One more suggestion that would be really useful: since the controversy is about the recent uptick, would it be possible to do a version where the time axis is just the last, say, 400 years?


  2. Thanks, Paul. I'm working on a version with multi-options, to show the different dating effects. I will probably use a 2000 yr interval; that's about 3 yr per pixel, which I think is quite a lot of pixels per resolution period.

  3. Nick, Thanks for fighting the good fight on WUWT. Needless to say, you don't get a lot of support there. Some people can't see what's happening right under their noses, if it challenges fossilized beliefs.

  4. Thanks Doug,
    I always try to remember that there are a lot more people reading than commenting.