Tuesday, December 27, 2011

1200425298.txt

From: Phil Jones <p.jones@uea.ac.uk>
To: trenbert@ucar.edu
Subject: Re: Draft paper on Chinese temperature trends
Date: Tue Jan 15 14:28:18 2008
Cc: david.parker@metoffice.gov.uk, thomas.c.peterson@noaa.gov, "Reinhard Boehm" <reinhard.boehm@zamg.ac.at>, "Susan Solomon" <susan.solomon@noaa.gov>, "Adrian Simmons" <adrian.simmons@ecmwf.int>

Kevin,
Homogeneity only done on mean T. Lots of sites just measure this.
A lot will measure max and min, but I haven't got the data. I also
didn't want to get into max/min as what is relevant to urban-related
warming in the global land series (or China) is the effects on mean T.
I can't then look at max or min against a rural series.
I would expect max to have changed less than min, but I can't
really look at that.
Also I don't want to confuse readers by saying there is an urban-related
temp influence, but it is to a lower DTR. I guess I could refer to Vose et al
(our Fig 3.11) which does show a decrease in DTR for 79-04 over China
(mostly blues).
I'll work on the text.
Cheers
Phil
At 04:50 15/01/2008, Kevin Trenberth wrote:

Phil
I looked at the paper in more detail. It obviously needs a bit of
polishing throughout.
I have a couple of fairly major comments. The first is that you only deal
with the mean temperature and nothing on the max and min temperatures.
Are those available? It would be much more powerful if those could be
included. The second is the special situation in China associated with
urbanization and that is air pollution. You do not mention aerosols and
their effects. We have some on that in AR4 that may be of value: refer to
our chapter.
In China, there has been so much increase in coal fired power and
pollution (11 out of the top worst ten polluted cities in the world are in
China, or something like that). So you do not see the sun for long
periods of time. Presumably that greatly cuts down on the max temp but
may also increase the min through a sort of greenhouse effect? Effects of
urban runoff tend to warm and space heating also warms but should mainly
affect the min. Pollution may not be in the inner city but concentrated
more near the sites of industry and power stations; but also may not be
that local owing to winds? Pollution may also change fog or smog
conditions, and may also change drizzle and precip. Looking at other
variables could help with whether the changes are local or linked to
atmospheric circulation.
The unique aspect of urbanization related to air pollution should make
China different, but may not be easily untangled without max and min temps
(and DTR).
Anyway, given these aspects, you may want to at least assemble the
expectations somewhere altogether and discuss max (day) vs night (min)
effects?
Hope this helps
Kevin
>
>> Dear All,
> I have mentioned to you all that I've been working on a paper on
> Chinese temperature trends. This partly started because of allegations
> about Jones et al. (1990). This shows, as expected, that these claims
> were groundless.
> Anyway - I'd appreciate if you could have a look at this draft. I
> have
> spelt things out in some detail at times, but I'm expecting if it
> is published
> that it will get widely read and all the words dissected. I know you're
> all
> very busy and I could have been doing something more useful, but it
> hasn't
> taken too long.
> The European examples are just a simple way to illustrate the
> difference
> between UHIs and urban-related warming trends, and an excuse to
> reference Luke Howard.
>
> Cheers
> Phil
>
>
> 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 p.jones@uea.ac.uk
> NR4 7TJ
> UK
> ----------------------------------------------------------------------------
___________________
Kevin Trenberth
Climate Analysis Section, NCAR
PO Box 3000
Boulder CO 80307
ph 303 497 1318
[1]http://www.cgd.ucar.edu/cas/trenbert.html

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 p.jones@uea.ac.uk
NR4 7TJ
UK
----------------------------------------------------------------------------

References

1. http://www.cgd.ucar.edu/cas/trenbert.html

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