Earthlights

NASA has just posted images of earth's night lighting ( street lights etc)  detected from satellite.

Clik for Global Image

The global image is 300KB and  is wider in terms of pixels than I usually display.  Depending on your software, you might not see it.   The two USA images below are 72 and 110KB
.It is perfectly clear that the distribution of night lighting could be used as a proxy for the UHI (urban heat island)  effect.  Greater concentration of lights =  greater UHI.  I understand GISS could be doing some work in this area to experiment with correcting temperature records for the UHI.   It is obvious though that third world night lights are not up to first world intensity.  There may also be other more subtle national differences to take account of if one starts equating night light images with the UHI effect.

Below I have superimposed the Jones 1994 stations and the V2 GHCN stations  over the earth lights image for the  USA east and west.  It is perfectly clear that most of the Jones  sites are from areas where satellites have detected  night lighting and because most wild animals do not turn on lights at night these NASA images are in fact confirming what many greenhouse sceptics have been saying for years.
That is; temperature record sites overwhelmingly are near human beings and because we tend to group in urban areas, the global temperature data sets are badly contaminated by the UHI.  These two images of the USA with stations superimposed  give the lie to the familiar statements over the last 15 years by the "global warming fraternity" to the effect that great effort has been made to exclude UHI affected data.

USA East

USA West

Due to requests I have added the image below that just shows the Jones / IPCC stations over the USA, so the bias in locations is clearer. Interesting that over the eastern half of the USA the relationship of stations to night lighting is very strong while over the less settled western states the network of weather stations has a more remote aspect. 
Also interesting that the image shows the red circles clearer over unlit areas.

USA Jones 1994 stations
 

De Bilt (Netherlands) grid cell NASA Earthlights showing Jones et al 1986-91 and  Jones 1994  stations superimposed demonstrating the majority of stations are in or in edge of illuminated / urban areas.

Uccle (Belgium)  grid cell NASA Earthlights showing Jones et al 1986-91 and  Jones 1994  stations superimposed demonstrating the majority of stations are in or in edge of illuminated / urban areas.

Posted 12, January, 2001

<> Updated 6, June, 2001
Update again 1 Nov 2005

© 2000 Warwick Hughes,
You saw the last three images  first here.

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