Definitions
from Wiktionary, Creative Commons Attribution/ShareAlike License
 v. to manipulate data to remove longterm trends in order to emphasise shortterm changes.
Etymologies
Examples

Rypdal and Rypdal show that this result is an artifact forced when Scafetta and West did not detrend the two time series and show that SFI is a Lévy flight while GTA is a fractional Brownian processl

Back to business, we have a figure to replicate. richardT , did I understand correctly, you detrend the simulated series as well?

The Chi square goodness of fit test to a Poisson distribution for the untreated data yielded a p = 0.09, while the data worked by Willis E. to detrend and with cycle removal gave a Chi square goodness of fit to a Poisson distribution of p = 0.87.

If you detrend, you can see a 60 year cycle of about 0.25C amplitude on top of that.

In the case of the Polar Urals data, we KNOW that the raw ringwidth data have strong biological growth trends and if we do not adequately detrend these trends, then we end up with a time series similar to the ones generated by both me and Steve see above.

You need to look at year to year variance, to detrend, etc.

Re #105, Judith, the MannEmanuel use of the global SST to detrend the AMO, versus using a linear trend, is a red herring.

They then attempt to “detrend” the tropical SST data not by taking out a linear trend, but by removing the global or at least hemispheric forcing of the surface temperatures.

Note the lack of a strong, “Ritson is wrong, one should never detrend” remark.

He used an RCS detrending method – which is essentially developing one growth curve for the site and using that for all trees rather than trying to detrend growth on a treebytree basis.
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