Sunday, May 13, 2012

4199.txt

date: Mon May 11 08:52:57 2009
from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: RE: Quick question
to: "Lockwood, M (Mike)" <mike.lockwoodatXYZxyzc.ac.uk>

Mike,
The new HadSST3 series should be ready some time this spring or early summer.
As the changes are potentially important, I think they will want to get it fully
peer-reviewed
before we combine it with the land data.
So keep in touch and I'll let you know when we have something new on the update pages.
I'm sure the HC folk are using ATSR to assess the drifter effect. There is a new
SST dataset called OSTIA, which is combining all the satellite and in situ data, but it
only starts very recently. I don't know if they are planning to take it backwards.
In all this, the land data has remained pretty much the same. I've been putting
together
some plots of our various versions over the years, and after adjusting for the differing
base
periods there is little difference. The land data are robust as they result from all the
countries doing different things. The issue about satellites and SSTs is that they result
from few sources, so when biases affect things they permeate the whole dataset. On land,
it is only Russia that is large enough to screw things up!
Look out for a paper in Weather fairly soon or urban effects. I'm sure this will stir
things
up when it appears, if anyone still reads Weather! I did this as I kept on hearing so
much rubbish talked about urban effects in London.
Cheers
Phil
At 09:18 09/05/2009, you wrote:

Hi Phil
Yes, I thought it would have been done - but just wanted to check. I came to the same
conclusion in that I estimated that we'd need 10 more years of decline from now on
before it was really significant. I might yet use what I have done as part of a paper
to counter the nonsense that Nicola Scafetta keeps spouting about dual timescale
responses to solar changes - but then I'm not looking to waste my time either! What I
could do, if you were happy with this, is use it alongside the same analysis applied to
HadCRUT4 when it is ready. Would be delighted to share authorship if you think that's a
worthwhile idea.
Thanks for the papers - they'll be very useful. Am in Stockholm and look forward to
reading them on 'plane back (as far as my ageing laptop battery allows)
No, I didn't know about the drifter buoys effect. Dare I ask, but are their effects
relevant to the recent difference between your reconstruction and GISS's? As a general
point, it does amaze me how bad we (=mankind) are about keeping vital data sequences on
our planet homogeneous. The worst example is space based radiometry. I hate to sound
like Nigel Fox, but he's absolutely right and the whole cosmic ray cloud thing would
never have got off the ground with properly intercalibrated instruments. Are the Hadley
folk using the ATSRs to calibrate the drifter effect? They ought to: that has been one
dataset that is decently homogeneous. (I do worry what might happen to it when the
Italians get hold of it, though!)
thanks again
Mike
------------------------------------------------
From: Phil Jones [p.jones@uea.ac.uk] Sent: Thu 07/05/2009 15:17
To: Lockwood, M (Mike)
Cc:
Subject: RE: Quick reply and another quick question ....
Attached a paper and a box in a longer article that do similar things to what you've
done.
So I think it's been done, unless you think otherwise.
The box is on page S20-21 of the bigger pdf. This is part of a much bigger article
on the State of the Climate System 2008 which will appear later in the year.
Bottom line - the no upward trend has to continue for a total of 15 years before
we get worried. We're really counting this from about 2004/5 and
not 1998. 1998 was warm due to the El Nino.

There are a lot of obtuse people out there, who will ignore these two refs - the first
is out,
the second by about late summer. There is another issue that you should be aware of.
It was alluded to in the third pdf.

There is an issue with all the buoy data (drifters) entering SST analyses since about
2000.
First there seem to be offsets of 0.1 to 0.2 deg C between these drifters and
conventional ships (drifters cooler). Drifters now dominating , providing about 80%
of the obs. Drifters sample the diurnal cycle better than ships, which may be one of the
factors
that could explain the difference. As the 61-90 period is a ship-based normal, this
means a cool bias (of about 0.1 deg C). Second, these drifters get to regions where
few ships used to go (the Southern Oceans for example), so our interpolated 61-90
normals get really tested! There will be a new version of HadCRUT3 (which we will call
HadCRUT4!) at some point later this year. The Hadley Centre need to finish their new
SST
dataset first (HadSST3). This will also sort out the 1945-60 issue in the Nature paper
and
add in more SST data for WW1 and WW2. Expecting to see the HadSST3 paper any
month now. Land will barely change. Likelihood is that the recent few years will
increase by up to 0.1
deg C. Effect gets worse as drifter/ship ratio increases.
Cheers
Phil

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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.jonesatXYZxyz.ac.uk
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