Tag Archives: smoothing

UC on Mannian Smoothing

Two comments from UC on smoothing CET using Mannian smoothing, a technique peer reviewed by real climate scientists (though not statisticians). I think these coldish years do matter, maybe now there will be some advance in smoothing methods. mike writes (1062784268.txt) ( I think this is somewhat related to CET smoothing (?) ) The second, […]

The Trick Timeline

Date: 16 Nov 1999, Phil I’ve just completed Mike’s Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith’s to hide the decline. Date: 22 Dec 2004, mike   No researchers in this field have ever, to our knowledge, “grafted […]

Spline Smoothing

The 2009 Climate Dynamics paper “Unprecedented low twentieth century winter sea ice extent in the Western Nordic Seas since A.D. 1200” by M. Macias Fauria, A. Grinsted, et al. discussed already on the thread Svalbard’s Lost Decades pre-smooths its data with a 5-year cubic spline before running its regressions. There’s been a lot of discussion […]

BS09 and Mannian Smoothing

Many CA readers have probably noticed Lucia’s recent coverage of Benestad Schmidt (JGR 2009) (with the inevitable acronym BS09). BS09 was an effort by B&S to verify Scafetta and West. realclimatescientists can also be climateauditors, I guess. It’s too bad that they don’t spend the same amount of energy examining Mann et al 2008 or […]

Smoothing Dongge

Mann reported a “significant” correlation of -0.5481829 between Dongge dO18 and gridcell temperature. Today I will report on exactly how Mann calculated this “significant” correlation. In keeping with recent requests, I will refrain from making any comments on this procedure, in the confident expectation that my critics will provide some commentary on what they think […]

Off-center Butterworth Filters

Today I’m doing a first reconnaissance of Butterworth filters, used extensively in Mann et al 2008. The comments here are notes and thoughts and I hope that some issues can be clarified by readers. As of 12.30 pm today, I think that that the main problem that I’ve had pertains to a difference between R […]

UC on Mann Smoothing

UC writes in that there’s another Mannian problem: And GRL08 ( http://www.meteo.psu.edu/~mann/shared/articles/MannGRL08.pdf ) is the prologue. Tried this new smoother ( http://www.meteo.psu.edu/~mann/smoothing08/lowpassadaptive.m ) with HadCRUT monthly and f=0.0104, [smoothedbest,w0,w1,w2,msebest] = lowpassadaptive(HadM, 0.0104); got this figure, But the weights are [w0 w1 w2] ans = 0.4100 0 0.5500 Surprisingly, this does not agree with the text, […]

Data Smoothing and Spurious Correlation

Allan Macrae has posted an interesting study at ICECAP. In the study he argues that the changes in temperature (tropospheric and surface) precede the changes in atmospheric CO2 by nine months. Thus, he says, CO2 cannot be the source of the changes in temperature, because it follows those changes. Being a curious and generally disbelieving […]

Mannomatic Smoothing and Pinned End-points

We’ve had a couple of discussions of dealing with end-points for smoothing. Here’s a little note about smoothing algorithms, which I think is pretty funny. It’s hard to imagine a note about smoothing algorithms being funny, but see what you think.

Briffa and MBH99 Smoothing

I’ve found an unlikely ally in my questioning of the smoothing of MBH99 in the original publication and in IPCC TAR: Keith Briffa. Not that Briffa has posted a comment endorsing my observation. However, the smoothed version of MBH99 in Briffa et al 2001 (near contemporary with TAR) is virtually identical to what I got. […]