Sinan Unur on GHCN

I have come across a simply wonderful animated representation of the
number of thermometer locations worldwide since 1701 in the Global Historical Climatology Network (GHCN) database by month.

http://www.youtube.com/watch?v=58mDaK9bH5o&feature=player_embedded#!

It is produced by a Turkish researcher, SinanUnur

Be patient while watching, it last 4 minutes. It is very slow to show any change at first since there were very few thermometers in the first century! Note the mass of stations in 1951 to 1980 (GHCN baseline period) and the subsequent decline. Ask yourself, for example WHY has Canada been virtually denuded of stations? Answer: the stations are still there, recording data. However, most of the data collected isn't used in any of the averages, models or projections. Cherry picking at its finest.

More here
http://blog.qtau.com/2010/05/dude-where-is-my-thermometer.html

Surprisingly, you will still find AGW conformists arguing that this decline in station numbers plus extreme selectivity is hunky-dory and that all is well in the GHCN gmt measurement world. I don’t think so.

Sinan states
“I do think it important to show that the averages are not being calculated using a fixed set of observational units.”

Thanks to Sinan. His work, started in 2007, adds weight to the research into GHCN by EM Smith at Musings from the Chiefio here http://chiefio.wordpress.com/category/ncdc-ghcn-issues/ here and Verity Jones here at diggingintheclay http://diggingintheclay.wordpress.com/

Here is another informative animation from Sinan showing how the cool and warm adjusted stations (blue and red segments) vary over time as a proportion and numerically of the total stations incorporated in the gmt calculation. Brill!
http://www.youtube.com/watch?v=ykWf44jfL4w&feature=player_embedded#at=114

Discussion here
http://blog.qtau.com/2010/05/adjustments-to-monthly-mean.html

I take it that the cool adjustments (I assume of historical data) and the warm adjustments of recent readings is to create the illusion of an exaggerated rising trend in the purported period of AGW 1970 onwards.

.......

Sinan just sent me an email which says:

I do think it is worth emphasizing that interpretation of the data
becomes really hard when the set of observational units changes.

I am also curious about what is going on in the "adjusted" data set.
Especially starting in Jan 2007:
http://blog.qtau.com/2010/05/here-is-looking-at-usa.html

Either the smaller subset of stations whose data are now being used do identify what is truly happening to the world's climate (in which
case, I would like a list of all such "good" stations with an
explanation to be made public)

Or we should use every scrap of data (even if it came from GIARABUB
http://blog.nu42.com/2010/04/what-is-up-with-giarabub.html ) in which case I do not understand why no effort is being made to add all
available data to the GHCN?

.......

I agree.