Posted by Jeff Id on December 15, 2009
A guest post by email from a Swiss Slovak reader. I’ve not verified it but it seems to be in line with what we find elsewhere in the global temperature record.
Yesterday I read an article about Alpine glaciers melting even faster
in 40ties than today, while “temperatures were lower then” and less
cloudy sky was blamed.
I made a chart showing ratio of melting, stationary and advancing
Swiss glaciers vs AMO already some time ago:
Today I asked the Swiss glacier Institute for precip and temperature
data and they linked me to Swiss meteo web.
I downloaded temp history of their main stations, which contained raw
and homogenized temperature charts.
Striking was, that all stations after homogenization showed steeper
trend than raw data. There is one unpersuasive example of sensor moved
from city to airport cited. Average difference between raw and
homogenized trend was 2.09 times higher for the latter data. More, the
flatter was the raw trend, the bigger was the homogenization upward
adjustment, in one example rising the trend seven fold.
I downloaded collated Swiss homogenized annual temperatures, showing
1.13 deg C/century warming trend. Then I back-calculated raw trend by
adding a linear decrease to the homogenized data to get 0,53 deg
C/century trend (1.13/2.09) and compared it with two truly rural
stations – irish Armagh Observatory and Slovak Lomnicky peak
Swiss raw data and both rural records are in very good agreement,
while Swiss “homogenized” data are climbing twice the rate. Swiss raw
data are not treated for UHI as far as I read, when some of the
stations are in the cities or on airports.