Re: [asa] Fw: Temperature Records

From: Iain Strachan <igd.strachan@gmail.com>
Date: Wed Dec 09 2009 - 09:27:05 EST

This looks quite interesting. I would be very interested to hear what Rich
Blinne has to say about this, as he knows the subject far better than me.

What appears to be a summary of the findings on the web page is that if you
use the raw data from temperature stations in Australia over the century
that there is no visible trend. However, all the data has been "corrected
for inhomogeneities", apparently by comparing data of a given station with
neighbouring stations. However, the final diagram he shows to which he
comments "double yikes", there appears to be a stepwise correction applied
at different periods to two of the stations at Darwin zero, and others are
apparently left alone, despite the fact that all the raw figures are in
close agreement. If this is true, it does look pretty fishy. I'm intending
to pull out the data myself; I have access to Matlab, which allows
statistical comparisons and charting to be done easily.

From my naive position of being very familiar for looking for trends in data
(I process medical signal data), but knowing nothing of the subtleties of
climate change calculations, is this. I would have thought the correct way
to correct for inhomogeneities would be to take a grand average of many
different stations (on the assumption that "inhomogeneities" are as likely
to be adjusted high as adjusted low. A more principled automated approach
would be to make a probabilistic model that allows the prediction of the
temperature at one station from the data from neighbouring stations. A
suitable candidate procedure for this would be to use Gaussian
Processes<http://en.wikipedia.org/wiki/Gaussian_Processes> which
can not only predict values but also error bars. In this way,
inconsistencies between stations could be highlighted.

I do think it strange that when corrections are applied for inhomogeneities
are made, that what seems to be no trend turns into a warming trend. It
sounds too much of a coincidence that all the corrections skew it the same
way.

Perhaps Rich could give us an explanation of why this is true?

Iain

On Wed, Dec 9, 2009 at 3:51 AM, Don Winterstein <dfwinterstein@msn.com>wrote:

> Randy suggested we skeptics engage with the data. A friend (PhD
> geologist) sent me the following message, which illustrates in great detail
> how another skeptic has engaged with the data. One of his principal
> conclusions: "*People who say that 'Climategate was only about scientists
> behaving badly, but the data is OK' are wrong.* At least one part of the
> data is bad, too." This is the kind of thing I suspected was going on all
> along (although things are apparently much worse than I suspected) and is
> the reason I proposed having all the data reinterpreted by a different set
> of scientists with different biases.
>
> Don
>
>
> Hi,
>
> You may find the info below of interest in assessing the validity of the
> temperature data used to document the history and extent of global warming.
> This is taken from some web postings by friends of mine.
>
> "Here's an "interesting" exposition of the methods used to cook the data re
> Global Warming. It's enough to make your blood boil."
>
>
> http://wattsupwiththat.com/2009/12/08/the-smoking-gun-at-darwin-zero/#more-13818
>
>
> "The "homogenized" data from HADCRU, GCN, and GISS cannot be trusted.
> Period. The Emails, bad as they are, are a distraction. The Devil is in the
> data itself. They need to throw it all out, and start over, using only the
> sparse amount of reliable raw climate data that exists." Note: GISS and
> Michael Mann have been caught cooking other data long before Climategate.
>
> "This analysis is for a single station. If you consider the likely error
> range for this one station, then consider the likelihood of similar errors
> at the thousands of stations used for determining the Earth's "temperature,"
> and what the combined effect of these errors are on the analysis, the only
> conclusion one can draw is that this data is totally useless for finding any
> meaningful result. Any actual change is simply buried in the noise."
>

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Received on Wed, 9 Dec 2009 14:27:05 +0000

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