Comments on: Mann 2008: the Luterbacher Mystery

By: Sam Urbinto

Sam Urbinto — Mon, 22 Sep 2008 18:12:53 +0000

Given the 5×5 cells at 0 are 5,408 km, 30 are 154,000 km, 60 are 267,000 km and 90 are 309,000 km, that would, combined with the coverage of stations in various areas, certainly add a large degree of complexity to the grid calcuations and importance.

Where do the GISS gridcells center? IIRC you’d mentioned they do some kind of size equalization or something like that. Weighting or whatever. I forget.

By: Sam Urbinto

Sam Urbinto — Mon, 22 Sep 2008 17:38:42 +0000

AFAIK, the grid starting at 45N 65E would have a center of 47.5N 67.5E

Steve: Yes. CRU gridcells are centered at the 2.5, 7.5 degree marks. GISS gridcells are different, but CRU are more common.

By: Steve McIntyre

Steve McIntyre — Sat, 20 Sep 2008 21:04:59 +0000

the luter data is in 5 degree gridcells, not 0.5 deg gridcells. Luterbacher et al 2004 uses Mannian style methods to calculate gridded data, but it includes instrumental info, that’s why the correlations are so high. IT’s totally inappropriate for saying that 484 series are significant.

By: Jeff Id

Jeff Id — Sat, 20 Sep 2008 20:47:55 +0000

So, the fun continues.

I don’t know how you caught that. The Luterbacher data is on even .5 degree coordinates while the rest of the data isn’t.

Very nice. There has to be some kind of interpolation going on.

Well the average of the 89 series of the original original set is the nearly an exact match to the average for the 71 series from the final original set.

By: Steve McIntyre

Steve McIntyre — Sat, 20 Sep 2008 20:18:48 +0000

In temperature datasets, they divide the world into 5 degree gridcells with centers at say 62.5N, 12.5E. If you look at the information in the table SD1 in Mann’s SI, the Luterbacher series are all associated with different gridcells. However, we have no original Luter data to compare it to, so it’s hard to say what he’s using.

By: Jeff Id

Jeff Id — Sat, 20 Sep 2008 20:14:31 +0000

Ok, I have spent enough time on this. It sucks being a newbie. When you say gridcell, do you mean that the Luterbacher data was in individual gridcells? Mann used some averaging or RegEM between gridcells?

I thought he did that for measured temperature only.

I just ran the average of the ‘original’ deleted 89 luterbacher series and it matches the average of the new Luterbacher within .15 standard deviation at the worst point. It is a near perfect fit.

I have chased this around my software for hours now. I kept asking how could they be the same average?

Some enlightenment if you don’t mind.

By: Steve McIntyre

Steve McIntyre — Sat, 20 Sep 2008 19:48:04 +0000

Hans, I’m famliar with that data reference. Mann uses gridded versions, for 71 different gridcells. I can’t locate original archives for the gridded data.

By: Hans Erren

Hans Erren — Sat, 20 Sep 2008 19:36:28 +0000

I discussed the summer temperature by Luterbacher at al. in
http://home.casema.nl/errenwijlens/co2/errenvsluterbacher.htm
originally published as
Jürg Luterbacher, Daniel Dietrich, Elena Xoplaki, Martin Grosjean and Heinz Wanner, European Seasonal and Annual Temperature Variability, Trends, and Extremes Since 1500, Science, Vol 303, Issue 5663, 1499-1503 , 5 March 2004

for which the results were put online as late as june 2006

Luterbacher European seasonal average temperature reconstruction results can be downloaded here
ftp://ftp.ncdc.noaa.gov/pub/data/paleo/historical/europe-seasonal.txt

here is a comparison for luterbacher summer vs Chuine wine harvest dates http://home.casema.nl/errenwijlens/co2/ChuineLuterbacher.gif

By: Steve McIntyre

Steve McIntyre — Sat, 20 Sep 2008 16:37:02 +0000

#6. Jeff, there’s one other possibility. In the WDCP infilled data set, there are 1355 series with the same core of 1209 series, but the other 146 series are 2×71 Luterbacher series (said to be summer, winter) and 4 log versions of the disturbed Finnish sediments. Why don’t you check and see if they’ve labelled a winter or summer Luterbacher series as annual?

By: Steve McIntyre

Steve McIntyre — Sat, 20 Sep 2008 16:32:14 +0000

#7. That was one of the things that I did in MM2003, where we found such interesting things as Mann’s unreported “adjustment” of the Gaspe series to “get” it into the troublesome AD1400 network. This was the ONLY such extension frontwards of a series in the entire archive. From an accounting perspective, this had alarm bells all over it, but no one in climate science cared. I collected quite a few series, but could only get a portion of them.

In the new data, many underlying series are at WDCP, but many are not. To my knowledge, the Briffa MXD data (called “SChweingruber” here) is available nowhere. I’ve sent an FOI to CRU in England but have received no response yet. They generally refuse FOI requests on one pretext or another but we keep trying and get occasional snippets.

I haven’t been able to obtain Luterbacher data yet. A reader emailed me this morning saying it was KNMI, but I am trying to clarify that as I can’t get it yet.

There are grey versions of data from Bradley’s associates e.g. speleothem data and that will be very hard to get.