Global, synched “blips” going in the same direction seem to defy the MWP/LIA “local” arguments, and to initially evolve from a widespread, instantaneous forcing — um, like solar.

CO2 doesn’t look to be having much effect at all, greenhouse or otherwise. Relevant for a subarctic site — supposedly the first areas affected by AGW. IIRC, the properly-analyzed Russian Urals results show something similar to this study.

In the sentence:

“Curiously, if one extracted the middle 6 digits from the 58 Schweingruber codes, one obtained 28 unique values, which matched exactly to the 28 codes in the combined ITRDB data.”

“58 Schweingruber” seems incongruous. Should it be “58 Esper” ?

In addition to stand density, how about position within the stand relative to the prevailing wind? And then there’s “amount of wind”, where trees grow most effectively where the relative humidity is as high as possible, so as to reduce evaporation in the leaf stomata.

By doing a “smoothed” average, the energy from each year is essentially spread out over the length of the filter…

A filter doesn’t spread it out, it removes it.

I’ve provided linkies on this site before on how stands are cored. Your concerns are assuming that stand density is even and openings don’t happen, in addition to not considering the way samples are taken, all of which is incorrect.

Best,

D

raising the question as to why some spruce sites correlate to temperature and some don’t.

It seems to me that stand density, alone, could account for “divergence.” It would be interesting to evaluate the effects stand density, if the data were available (which it probably isn’t). Assume average yearly air temperature IS a major factor controlling growth. Then, those spruce trees which have access to full sunlight (that is, those that are “in the open”) would be above the minimum temperature required for growth longer each day than those not in complete sunlight (since leaf temperatures in sunlight are higher than those in shade at a given temperature). And they would be at or above this minimum temperature longer each day if average air temperatures are increasing. Other factors being equal, they might show increasing growth rate with increasing average air temperature. Now, consider a poor little spruce that is being gradually shaded more and more by it’s neighbors. The effects of increasing average yearly air temperature could easily be more than offset by the shading effects as all the trees in the stand continue to grow. Lack of adequate moisture or poor soils could also greatly retard growth for trees that are spaced closely, more than offseting any effects of raising temperatures. Adjustments for tree age would not correct for these effects.

Do any of these dendro studies provide a good description of the site? A great deal more information is needed before tree rings can serve as proxies without cherry-picking, IMO.

Another thing I’m curious about, Steve, do the correlations occur against [i]local[/i] temperature records or global means? I think it may be MUCH more accurate to correlate against unfiltered local records because, well, quite simply, the temperature in China in 1865 doesn’t have much impact on a tree in NA in 1885, let alone 1865. By doing a “smoothed” average, the energy from each year is essentially spread out over the length of the filter, and impacts any correlation function that is performed.

This could also explain poor r2 statistics as local and global temperature records do not jive in the least.

Mark

Congratulations on the detective work but why for pity’s sake won’t these people give proper and accurate citations? Is it a fetish?

This Esper site is not incorporated into the Osborna and Briffa [2006] set of 14 series, presumably on the basis that the ring width chronology does not correlate to temperature – raising the question as to why some spruce sites correlate to temperature and some don’t.

Because they’ve been paid by Big Oil not to?