Re: [asa] Data doesn't support global warming

From: Dave Wallace <wmdavid.wallace@gmail.com>
Date: Wed Dec 16 2009 - 14:39:18 EST

Kenneth Piers wrote:
> By the way it does seem fairly inconceivable to me that, if one was interested in collecting valid temperature data, one would locate the thermometer near or above an outdoor AC. I have an old thermometer outside my kitchen window on the east side of my house. In the winter this thermometer always reads about 2-3 deg F above the air temperature because of heat transfer through the nearby window. The actual magnitude of the temperature anomaly depends on the air temperature and the indoor temperature. The bigger the difference between these two, the bigger is the anomaly.

Rich Blinne wrote:
> That's EXACTLY what Peterson did. He compared the trends of poorly sited and well sited stations and the trends were the same, proving the reliability of the homogenization procedure. In addition to Peterson, the entire calculation was done redone only using the well-sited stations. It gave the same answer as when the poorly sited stations were included. See the instrumental record chapter of the IPCC report http://ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Print_Ch03.pdf and look at Figure 3.3 on page 244. (Note: the suggestion that both Randy and I have made of Glenn doing a systemic study of bad stations can be short circuited by him posting Figure 3.3 to his web site.)
>
I have been off list for a while and then subscribed but was not
replying to anything.

As I read him Peterson looked at the urban heat island effect not at
effects related to poor or anomalous site selection.

By poor or anomalous site selection I mean:
a: near AC especially window or old units
b: near high efficiency furnace smoke outlets at the sides of houses (up
hear in the frozen north (-9C out right now), fumes from our furnaces
used to go up the chimney but with the high efficiency furnaces it goes
out the side of the building and impacts local temperature just like AC
does)
c: in places where construction or plant growth... has turned the
location into a "sun trap"
d: near to rivers, streams etc whose flow has been substantially changed
by dams, power stations etc

I assume that Peterson excluded any stations that have ever have had a
significant (30000) population nearby since 1930. It seems to me that
his results are a significant factor on the side of the pro AGW camp wrt
the UHI effect, although I find it very counter intuitive.

Heating a building using a furnace to a given temperature tends to heat
the surroundings which in turn requires less energy to heat the whole
urban area, thus it operates in a negative feedback system. Heat pumps
used for heating tend to cool the surroundings and thus run in a
positive feedback fashion, but since they are not common I consider them
irrelevant. Whereas with AC the hotter the urban temperature becomes
the more the AC runs thus AC works in a (limited) positive feedback heat
flow system. The new high efficiency fixed AC units contain such a
large fan that the local temperature is not greatly affected as they can
homogenize the air temperature for quite a surprising distance. We have
central AC and updated our unit a few years back. The heat exchanger is
located at the side of the house between the neighbour's house (10-12
ft) and ours. Before we upgraded that area would get unbearably hot,
whereas now it has a similar temperature to the back or front of the house.

Also your US Climate Extremes Index for all four seasons is very
suggestive of GW.

Dave W

(index positive effect)

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Received on Wed Dec 16 14:39:46 2009

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