On Mon, 8 Sep 2003 16:24:51 +0100, "martin rowley"
wrote:


"Philip Eden" philipATweatherHYPHENukDOTcom wrote in message
. ..

... the strong signal for increase in night minima also shows up
in the CET *annual* record as at:-

http://www.metoffice.com/research/ha..._dif_graph.gif

from the mid-1980's to present-day. Though it's worth pointing
out that this graph also indicates a similar rise (though
significantly lower values wrt today) during the 1890's which
then ran out of steam early in the 20th century.

I am by no means a global warming sceptic but I am cautious about what
I read. I'm interested particularly in the adjustments made for
urbanisation i.e. "Since 1974 the [CET] data have been adjusted by 1-2
tenths °C to allow for urban warming." which is copied from:
http://www.metoffice.com/research/ha...sdata/CET.html

However, significant urban warming was occurring before 1974. I recall
a paper published in "Weather" (IIRC) in the late 1960s or early 1970s
about increasing positive anomalies in the night minima at Manchester
Ringway since the 1940s. During this period of at least 20 years,
anomalies in the CET night minima appear to have been declining. Yet
there was a significant increase at Ringway which was attributed to
increasing urbanisation. I know this because I did the initial
research that prompted the article and I think the anomaly was around
+1 degree F over that period.

Can anyone supply a link to details of adjustments made to the CET for
urban warming and of the rationale? This would be much appreciated.

--
Dave