On Sat, 17 Jul 2004 11:51:19 +0100,
Tony Raven said:
Quite. And spreading urbanisation moving ground weather stations from
rural to urban locations is thought to be one of the reasons that
satellite tropospheric temperature measurements have not seen the same
global warming that ground stations have. The US has taken much greater
care to remove urbanisation from the temperature measurements and do not
show the same warming that the global weather station network does.
Have a look at the graphs on the NASA Goddard site for examples
-http://www.giss.nasa.gov/data/update/gistemp/graphs/
There has been some significant reanalysis of these tropospheric (O2?)
temperatures and the temperature signal has included a significant
proportion of the stratopheric (O? O2) signal (20%IIRC).
Tim.
Nature 429, 55 - 58 (06 May 2004); doi:10.1038/nature02524
Contribution of stratospheric cooling to satellite-inferred
tropospheric temperature trends
QIANG FU, CELESTE M. JOHANSON, STEPHEN G. WARREN & DIAN J. SEIDEL
From 1979 to 2001, temperatures observed globally by the
mid-tropospheric channel of the satellite-borne Microwave Sounding Unit
(MSU channel 2), as well as the inferred temperatures in the lower
troposphere, show only small warming trends of less than 0.1 K per
decade (refs 1-3). Surface temperatures based on in situ observations
however, exhibit a larger warming of 0.17 K per decade (refs 4, 5), and
global climate models forced by combined anthropogenic and natural
factors project an increase in tropospheric temperatures that is
somewhat larger than the surface temperature increase. Here we show
that trends in MSU channel 2 temperatures are weak because the
instrument partly records stratospheric temperatures whose large
cooling trend offsets the contributions of tropospheric warming. We
quantify the stratospheric contribution to MSU channel 2 temperatures
using MSU channel 4, which records only stratospheric temperatures. The
resulting trend of reconstructed tropospheric temperatures from
satellite data is physically consistent with the observed surface
temperature trend. For the tropics, the tropospheric warming is 1.6
times the surface warming, as expected for a moist adiabatic lapse
rate.
--
God said, "div D = rho, div B = 0, curl E = - @B/@t, curl H = J + @D/@t,"
and there was light.
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