date: Thu Jul 3 09:43:17 2008
from: Phil Jones <p.jonesatXYZxyz.ac.uk>
subject: Re: Small request
to: Pete Lamb <plambatXYZxyzedu>
Here's the series I would recommend. It comes from this paper
Brohan, P., Kennedy, J., Harris, I., Tett, S.F.B. and Jones, P.D., 2006: Uncertainty
estimates in regional and global observed temperature changes: a new dataset from 1850. J.
Geophys. Res. 111, D12106, doi:10.1029/2005JD006548.
and is the one used in the 2007 IPCC report - the chapter I co-ordinated with Kevin.
Trenberth, K.E., P.D. Jones, P. Ambenje, R. Bojariu, D. Easterling, A. Klein Tank, D.
Parker, F. Rahimzadeh, J. A. Renwick, M. Rusticucci, B. Soden and P. Zhai, 2007:
Observations: Surface and Atmospheric Climate Change. In: Climate Change 2007: The Physical
Science Basis. Contribution of Working Group 1 to the Fourth Assessment Report of the
Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M.
Marquis, K.B. Averyt, M. Tignor and H.L. Miller (eds.)], pp235-336, Cambridge University
Press, Cambridge, United Kingdom and New York, NY, USA.
In the file, there are two lines for each year from 1850 to 2008. Ignore the second of
each pair of lines - this is the % coverage of the Earth's surface with data.
For the first line, the first 12 numbers after the year are Jan-Dec. I suspect you'll
want the annual, so take the 13th number. Ignore the 14th, as this is another
estimate of the annual.
The annual values are all wrt 1961-90. All you need to do is plot these against the
year and put a smoother through them. You should then get something like the
figure on the CRU home page. Your smoothing may be different, but the yearly
values should be exact.
2008 has data through May and it's annual value based on these 5 months.
2008 is relatively cool, but this is due to the La Nina, which makes the world
cooler as El Nino makes it warmer. The 1998 record should go when we have the
next reasonable El Nino.
My rule of thumb about the ENSO influence is that if you take our SOI, which
ranges from ~3 to ~-3, each unit of the SOI explains about 0.06 deg C of global T.
SOI also leads, so this reg weight comes from looking at high-freq variations
of annual global T values versus July (of year -1) to June of the current year. So
1998 was about 0.15 warmer because of the El Nino and 2008 about 0.10 cooler
due to the La Nina. 2008 should be cooler than 1998 due to ENSO by about 0.25.
Above just a bit of background as you'll likely have to explain why we're apparently
not warming. A lot of the skeptics make a big thing about 1998 and apparent cooling
since then. ENSO influence on the year-to-year temps is large compared to the
0.02 deg C per year due to global warming if you assume we are warming at 0.2 deg C
per decade. 2008 should be about 0.2 warmer than 1998 due to global warming.
The values for 1998 (+0.526) and 2008 (+0.247) don't add up - the ENSO difference
is about right but the GW part isn't, but as you know there are a lot of other
circulation and other influences in the climate system - which your article
will allude to!
Hope all is well!
At 21:12 02/07/2008, you wrote:
I'd be very grateful if somebody in CRU could e-mail me an updated version (through
2007) of your time series of globally averaged surfaced air temperature. I need the
diagram (or its numerical equivalent) to complete a article for my hometown newspaper in
New Zealand (Nelson Mail).
I hope you are doing well. Thanks in advance,
Peter J. Lamb
George Lynn Cross Research Professor
Director, NOAA Cooperative Institute for
Mesoscale Meteorological Studies
The University of Oklahoma
120 David L. Boren BLVD.,Suite 2100
Norman, OK 73072-7304
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