Earthlights
NASA has just posted images of earth's night lighting ( street lights etc) detected from satellite.
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.
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.
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
© 2000 Warwick Hughes,
You saw the last three images first here.
