Comments on: NASA Step 2: Another Iteration

By: Frank Upton

Frank Upton — Wed, 02 Jul 2008 11:23:57 +0000

I suppose the 100 or so versions with no data might be versions that did not, shall we say, give appropriate results and were abandoned.

By: John Goetz

John Goetz — Tue, 24 Jun 2008 02:36:45 +0000

Folks, what Steve did here to tease the tiniest details out of the methodoolgy is quite amazing. I started clawing my eyeballs out over a week ago when I could no longer follow the notes I had made on the routines only a few hours earlier.

I agree that some of the details – such as how much to weight a station 200km away, probably don’t matter much. It is seemingly more arbitrary decisions – such as zeroing the last year or extending the overlap 50%, that seem to have greater and more bizarre impacts. Furthermore, none of it seems documented in the peer-reviewed literature.

By: Steve McIntyre

Steve McIntyre — Mon, 23 Jun 2008 17:18:24 +0000

#15. There are some things that would make sense to do. I am not prepared to spend the time to set them up. It makes a lot of sense to coordinate blog entries with a wiki style record and some efforts in this direction have been made. But they are not ones that I’ve been involved with and tend to have a little less drive and lose focus. Also the brand here is pretty strong and drives a lot of traffic, so that there’s little point not using the brand. I would dearly like to have a climateaudit wiki to provide a bit of a joint archive, but someone would have to do it and satisfy someone that I know (like John A or Pete or Nicholas or Anthony) that it’s going to work.

By: Larry T

Larry T — Mon, 23 Jun 2008 17:15:08 +0000

I hop;e this isnt too off topic for this particular thread but I think that using longest overlap period etc as criteria for order of combining data and weighting makes little sense to me. I would think that promary weights should be to those stations whose temperature record was best ( least amount of missing data) and/or most consistent (lowest std dev maybe).

By: TheDude

TheDude — Mon, 23 Jun 2008 16:31:47 +0000

Speed it up, Hansen wants you to go to jail for this:P, naw, seriously

http://www.guardian.co.uk/environment/2008/jun/23/fossilfuels.climatechange

By: Arthur Edelstein

Arthur Edelstein — Mon, 23 Jun 2008 16:23:31 +0000

Per Steve's request, I have worked out how to generate text files (instead of the usual binary output) from the STEP2 code of GISTEMP. All sources and output files (binary and text) can be downloaded here, either in a single zip file or in individual files.

By: Kieran

Kieran — Mon, 23 Jun 2008 16:05:04 +0000

First comment from multi-year lurker:

Steve, would it be worth creating a Sourceforge/Savannah project for this work, so that version tracking/bug tracking
is available, and third-party contributions can be made?

By: Steve McIntyre

Steve McIntyre — Mon, 23 Jun 2008 12:48:52 +0000

#13. With a proper methodology, a variety of studies can be carried out. This particular sensitivity is low on my list, but we’re getting towards the point where tools will be available. But I’ll be showing some things that will make you scratch your head much more this particular weighting system.

By: Michael Jankowski

Michael Jankowski — Mon, 23 Jun 2008 12:20:22 +0000

Re#11, it may not bother you, may not be relevant to this thread and what you’re attempting to do in general, and may only have a small impact on results. But while there may not be a “magic formula,” the weighting methodology should have to be justified somehow.

I guess when all of the code has been decoded into R, maybe someone can do some sensitivity analysis regarding inverse linear vs inverse square, 500 and 1000 km cutoffs vs 500 only, or 250 and 750, etc, to see how much of an effect these seemingly arbitrary intermediate steps have on the end result.

By: Steve McIntyre

Steve McIntyre — Mon, 23 Jun 2008 12:02:58 +0000

I’ve made a slight change to the hansenref subroutine to fix a problem that didn’t affect Wellington but did affect Batticaloa, which now is reconciled as well.