On Thu, 03 Dec 2009 10:56:03 EST, Wes Deviers said: > I think he was referring to the idea that previously rural senors are > becoming > urban without necessarily taking that into account when you look at the data. > > For instance, say you have 30 weather stations along the stretch of 81 > between > Blacksburg and Roanoke that were put in place in the 1950s and have been > continually monitored. As Roanoke and the Blacksburg/Christiansburg Greater > Metropolitan Area of Traffic Growth have expanded towards each other, the > heat- > island effect would have expanded with it. So assume 10 of the 30 sensors > have > shown continuous temperature increases since 1950. How much of that is due > to > global warming, and how much of that is due to urban expansion? > > A climatologist at VT would take that into account in their localized > studies. > Somebody at NOAA, viewing raw numbers in a text file, has no way to control > for > that. It's not that cities are hotter, is that the hot areas around cities > expand with the cities, and national or international datasets cannot account > for it. > > If just 5% of your weather data points from 1960 were rural but in 2009 are > urban or suburban, how much does that skew the entire set?
Here's a nice thread about how they deal with this stuff. And apparently, the raw numbers *do* include a tag for this, so "somebody at NOAA" can do the applicable controls. People start posting actual stuff around reply #5: http://www.physicsforums.com/showthread.php?t=359423 Of course, it's exactly these sort of corrections to the data that have the climate-change deniers jumping up and down yelling 'ZOMG! Cooked Data!', and why many of the scientists advocated not releasing the raw uncorrected data.
pgp7OEYFVnB40.pgp
Description: PGP signature
_______________________________________________ Fun and Misc security discussion for OT posts. https://linuxbox.org/cgi-bin/mailman/listinfo/funsec Note: funsec is a public and open mailing list.
