Comments on: D’Arrigo et al. on Bristlecone Calibration

By: Wilson on Yamal Substitution « Climate Audit

Wilson on Yamal Substitution « Climate Audit — Sat, 16 Apr 2011 20:05:15 +0000

[...] away from it. It’s too bad. D’Arrigo et al 2006 is a vastly superior paper. I published some first comments on Feb 11 focussing on bristlecones. In response to that note, Rob wrote to say that he used [...]

By: Pat Frank

Pat Frank — Mon, 13 Feb 2006 06:47:24 +0000

Thanks, Steve — the format clarification helped a lot. I have an application called “Kaleidagraph” that can help me sort out the rest. Now that I know what it is.

Pat

By: Steve McIntyre

Steve McIntyre — Sun, 12 Feb 2006 20:23:08 +0000

Pat, I’ll post up a function which I use to convert WDCP data to a time series – it works for most WDCP records, but there are a few oddball formats and I spent quite a bit of time a couple of years editing and fiddling with this.

They report data in an antique format left over from punch cards and memory problems. the first entry is the tree code (but sometimes the last digit is a core# within the tree). The date is usually the first year of a decade, but if it’s not a full decade present is the first available year. The values are by year for the decade. I’ll post up some functions a little later at http://data.climateaudit.org/scripts/tree.functions.txt.

You can use them in an R program by just
source(“http://climateaudit.org/scripts/tree.functions.txt”)

R is really quite magical for this sort of thing.

The White mountains B is an old compilation.

By: Pat Frank

Pat Frank — Sun, 12 Feb 2006 20:15:12 +0000

Thanks Steve — I’ve accessed the fixed links. Thanks also for the heads-up about those “999″‘s. I had no idea what they were for, but they sure do screw up a plot.

But a question: in the NOAA.gov tree ring data, e.g., the “White Mountains B” compilation, the first entry is presumably a tree-code, the second is year, and is the rest of each year-line of numbers just repeated measurements of widths at different points on a ring? Should one then just average these numbers to get a net tree ring width for a given year, +/- SD?

Why, by the way, in the WMs B data set, do all the 1960 strings end early? Hmmm — maybe I should just consult Schulman and Fritts. Apologies for bothering you with picayune questions.

By: Steve McIntyre

Steve McIntyre — Sun, 12 Feb 2006 01:05:44 +0000

Pat, I’m very familiar with this site. One of the irritating aspects to their tree ring data is that the formats sometimes are inconsistent between authors. In 2003, when I was collating data for the MBH principal components calculation, I made consistent R-objects of all the crn (chronology) and rwl (measurements) files and made a table of details – site, location, altitude, start, end, author, species, etc. as an R object for each of the regions. I use these all the time. WDCP also has irritating use of 999 to end lines – it’s very irritating when there are values in the same range. However, on balance, WDCP is very good. I’ve corresponded frequently with their data manager, who has been very cooperative.

By: Pat Frank

Pat Frank — Sat, 11 Feb 2006 22:05:05 +0000

Steve, neither one of your climateaudit bristlecone URLs worked for me. Looking about, I did find this NOAA site that seems to archive lots of tree ring data, and that offers a very explicit search regime:

http://www.ncdc.noaa.gov/paleo/ftp-treering.html

Now, to figure it out.

Steve: I fixed the directory. The links should work now. I think that one of the reasons that these guys don’t archive their data sets is that once you see them, the analyses that they carry out are so trivial. The only heavy lifting, and it’s laborious rather than complicated, is mastering the data sets.

By: hans kelp

hans kelp — Sat, 11 Feb 2006 17:20:07 +0000

As I see it it is now becoming crystal clear that the work of
Steve McIntyre has begun to make it´s impact on the community. Respect, respect!. Two contradictionary research results published within the same week and certainly from people of within the very same community, that must spell trouble for the Hockey Teams (and Science). Now people start to take the work of S.M. seriously. About time!

By: JerryB

JerryB — Sat, 11 Feb 2006 16:50:19 +0000

Just putting the full citation into this thread:

D’Arrigo, R., Wilson, R. and Jacoby, G. 2006. On the long-term context for late 20th century warming. Journal of Geophysical Research, Vol. 111, D03103, doi:10.1029/2005JD006352,

By: jae

jae — Sat, 11 Feb 2006 15:15:04 +0000

WOW. They sure can’t both be right! Bet you won’t see a discussion of this over at realclimate.