Saturday, March 31, 2012


cc: Francis Zwiers <>
date: Fri Oct 1 09:20:07 2004
from: Phil Jones <>
subject: Re: Global warming
to: "Fudge, Dennis WLAP:EX" <>

Hopefully you can read pdf files. The attachment and maybe some of the references in it
give you the answer to your question(s).
Each station is in one of our grid cells (5 by 5 deg. of lat/long) and we use anomalies
(departures) from the 1961-90 period (12 monthly averages for each station). Some boxes
based on many stations, some on just one. The paper refers to another in JGR from 2001
(Jones et al., 2001) that adjusts the variance of the series to account for differing
numbers over time. You can read a little more about this on our web site
[1] then go to data, then to temperature. There are a number of
FAQs there as well. We do a small amount of extrapolation - see the paper.
I have cc'd this message to Francis Zwiers, who is the Canadian Govt scientist (at
you might like to contact for further info. He was involved in a project to adjust
temperature data for many of the problems of site changes and observational practice
changes that have occurred over the years. For Canada, we have incorporated this dataset.
We try to include as much of this work as possible, but for a lot of countries we have to
do this
work ourselves. This is sub-optimal as we don't have all the necessary metadata (data
data), but we do the best we can.
I will be travelling much of October, but if you have any additional questions email
me. Francis is
also likely travelling as well, but he should be also able to answer most questions.
At 18:38 28/09/2004, you wrote:

I have been trying to find information of how the temperature trends are
calculated. I have contacted several people from the Canadian Federal
Government but no one was able to
answer my question.
I know the temperatures are average for each grid cells. But using just one
grid cell as an example und using only land stations and ignoring the
weighting applied; If there were 10 meteorological stations in that cell in
1970 and there are now 7 stations, are only those seven station used for
every year? Or are all stations used when ever available? If all stations
are used, is there an effort to extrapolate for the now none operational
Dennis Fudge
Air Pollution Meteorologist
Ministry of Water, Land and Air Protection
If you woke up breathing, congratulations! You have another chance!

Prof. Phil Jones
Climatic Research Unit Telephone +44 (0) 1603 592090
School of Environmental Sciences Fax +44 (0) 1603 507784
University of East Anglia
Norwich Email

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