date: Mon Apr 28 13:14:35 2008
from: Phil Jones <p.jones@uea.ac.uk>
subject: Re: FW: Talk on Understanding 20th C surface temperature
to: "Sear, Chris (CEOSA)" <chris.sear@DEFRA.GSI.GOV.UK>, "David Parker" <david.parker@metoffice.gov.uk>, "John Kennedy" <john.kennedy@metoffice.gov.uk>

    Chris,
       David Thompson is giving a talk here tomorrow on this.
    The essence of his talk will be in Nature in a few weeks time.
        The skeptics will make a meal of this when it
    comes out,  but if they did their job properly (I know this is impossible!) they would
    have found it. It relates to a problem with SST data in the late 1940s. The
    problem will get corrected for at some point. SSTs need adjusting as there must be
    from buckets for the period from Aug45 by about 0.3 gradually reducing to
    a zero adjustment by about the mid-1960s.  The assumption was that after WW2 they were
    all intake measurements and didn't need adjusting.
       This will reduce the 1940-1970 cooling in NH temps. Explaining the cooling
    with sulphates won't be quite as necessary.  It won't change century-scale trends.
      There is much more of an interesting thing going on now. With all the drifters
    now deployed measuring SST, the % of ships making measurements in now
    only about 40% of the total - whereas it was all in the late 1990s. In comparisons
    over the last 10 years it seems that ships measure SSTs about 0.1-0.2 higher
    than the drifters/buoys. As the 61-90 base period is ship based, it means
    recent anomalies are colder than they should be (by about 0.1 for global mean
    T in the last 2 years).
      Working on a press release with MOHC about the Nature paper.
     We've been though page proofs with Nature, but these don't yet include figs.
    I can send these when we get them.
    Cheers
    Phil
   At 12:55 28/04/2008, Sear, Chris (CEOSA) wrote:


     David, John, Phil
     Do you know and can comment on this work?
     Ta
     Chris
     -----Original Message-----
     From: McCloghrie, Paul (CEOSA)
     Sent: 28 April 2008 12:51
     To: Sear, Chris (CEOSA)
     Subject: FW: Talk on Understanding 20th C surface temperature
     variability
     Might be of interest if you're in Cambridge. I did some work with David
     Thompson years ago and he was doing time series analysis back then too!
     Paul
     -----Original Message-----
     From: Leverhulme Climate Symposium [[1]mailto:climate@esc.cam.ac.uk]
     Sent: 28 April 2008 11:58
     To: climate@esc.cam.ac.uk
     Subject: Talk on Understanding 20th C surface temperature variability
     Dear Colleagues,
     David Thompson of Colorado State University will be speaking in
     Cambridge
     on 22 May on 'Understanding 20th century surface temperature
     variability'.
     His talk will 'highlight a glaring but previously overlooked error in
     the
     time series of global-mean temperatures', see full abstract below. (For
     those too far from Cambridge to attend, this is for information and
     interest).
     The prevailing view of 20th century temperature variability is that the
     Earth warmed from ~1910 to 1940, cooled slightly from ~1940 to 1970, and
     warmed markedly from ~1970 onward. In this talk I will exploit a
     physically-based filtering methodology which provides an alternative
     interpretation of 20th century global-mean temperature variability. The
     results clarify the consistency between the century- long monotonic rise
     in greenhouse gases and global-mean temperatures, provide new insights
     into the climatic impact of volcanic eruptions, and highlight a glaring
     but previously overlooked error in the time series of global-mean
     temperatures.
     Thursday  22 May, 2.15 pm in Meeting Room 2, Centre for Mathematical
     Sciences (between Clarkson and Madingley Roads)
     Department for Environment, Food and Rural Affairs (Defra)
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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.jones@uea.ac.uk
   NR4 7TJ
   UK
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