date: Fri Jan 28 17:04:11 2005
from: Phil Jones
subject: Re: FW: Crok Story on Hocky Stick - English
to: "Folland, Chris" , JOLLIFFE IAN
Chris,
Have you seen this web site? [1]http://www.realclimate.org/ Perhaps you should
on this issue.
Raising and lowering a series (i.e. changing the base period) won't affect the
correlation matrix. So all the work CRU has done in this regard is unaffected
by this.
I also think it shouldn't make much difference to PCs calculated with the
covariance matrix. It might change the order of some.
This appears to relate to Mike's calculation of PCs using SVD. I'm not good
enough at Maths to know why.
Mike does answer all this on the above web site. Also the paper they mention
coming out in GRL was reviewed by hydrologists. It seems you can specify
an editor and if the editor doesn't know the subject they can get it reviewed or
send to one who does. The editor here had an agenda.
The web page is interesting, but whatever you do don't delve too deeply. It
will just eat into your time and in the end be completely useless. Ray Bradley
wanted something put there on 2004's temperatures. I gave him the WMO
press release from mid-Dec04. Some of the comments on that are ridiculous.
It has generated quite a few. The whole web site has got a lot of interest,
but it is only for those with time on their hands.
Cheers
Phil
Cheers
Phil
At 16:32 28/01/2005, Folland, Chris wrote:
Phil
If you base the data anomalies in an EOF analysis on a recent
climatological period, does this really change the shape of the time
series compared to the full period. This is a common method due to data
limitations. This seems to be one key criticism of the Mann hockey stick
(not the only one).
Chris
Professor Chris Folland
Head of Climate Variability Research
Global climate data sets are available from [2]http://www.hadobs.org
Met Office, Hadley Centre, Fitzroy Rd, Exeter, Devon EX1 3PB United
Kingdom
Email: chris.folland@metoffice.gov.uk
Tel: +44 (0)1392 886646
Fax: (in UK) 0870 900 5050
(International) +44 (0)113 336 1072)