To: tom crowley <email@example.com>, "Michael E. Mann" <firstname.lastname@example.org>
Subject: Re: mill records
Date: Mon Aug 7 13:58:54 2000
Tom and Mike,
What Tom said is essentially correct. Tim Osborn here recalibrated
each series, as a composite, against the same NH series for the April-
Sept average north of 20N (using land only data). All this does is
rescale the series as it is simple regression (y=ax+b). Because y is
based on temps wrt 61-90 this means that the axis is then wrt 61-90.
Doing this we can then add the same instrumental temp series. It also
brings the series together and the web page was just for illustrative
purposes. For Mike's series you get pretty much the same result by
subtracting 0.12 from Mike's numbers as this is the difference between
Mike's base period and 1961-90.
There is nothing sinister going on ! I'll summarise this to Rob.
PS I seem to be stirring up loads of emails about historical data. You
are both on those emails so you can see what crap is being written and my
(time wasting for me) replies. Apologies for replying. I should know better
and keep quiet. We can all expect more of this if IPCC stays in roughly
the same form pre-Victoria. It's relatively easy to knock historical
records, so as long as it gets no worse than this we'll be fine.