Fist off, a h/t to George here:
Then, the meat of it. This article, by Warwick Hughes points out how repeated moves of a station out of the urban core can ‘lock in’ UHI as ‘global warming’. It claims that the method, as described in the PDF is done in New Zealand and provides the links.
I’m downloading the PDF about the New Zealand work now from here:
but it’s going to take me a while to work through it all.
Until then, this looks like exactly the kind of “oopsy” that I’ve seen elsewhere. Splice Artifacts treated as gospel. That is why in calorimetry it is a First Rule to never screw around with the thermometers…
NIWA at their site claim that splicing together stations with step corrections confirms global warming:
NIWA’s long-running ‘seven-station’ series shows NZ’s average annual temperature has increased by about 1 °C over the past 100 years.
Locations in the “seven station” series
The series has been derived from seven locations:
Auckland = Masterton = Wellington = Hokitika = Nelson = Lincoln = Dunedin
These locations were chosen because they provide broad geographical coverage and long records (with measurements started at all sites by 1908).
How the ‘seven-station’ series is constructed
For each location, temperature records from a number of local sites have been merged together to form a long time series. When merging different temperature records like this, it is necessary to adjust for climatic differences from place-to-place, or even changes in exposure or instrumentation at the same site. If no adjustments are made, significant biases could be introduced. For example, the longest record in the country comes from Dunedin, with climate readings taken at six sites throughout its history.
So it’s “all about the splice”…
Warwick Hughes does a great job showing how a splice can fabricate warming, so basically it will come down to how well their method of splicing does or does not remove UHI artifacts. From what I’ve seen, “climate scientists” do a terrible job of it….
Simple GISS diagram illustrating warming effect of conventional “adjustments” of “step” in T data due to site moves outward from urban centre.
January 2nd, 2011 by Warwick Hughes
I have been reading the 169 page NIWA pdf – “Report on the Review of NIWA’s “Seven-Station” Temperature Series December 2010″ – downloaded here
I have not yet found the BoM review – only the one page letter from the BoM – see pdf page 13 in the above.
I draw readers attention to the excellent little GISS diagrams which perfectly illustrate the warming effect of adjusting out the multitude of step changes which are common throughout all temperature data as thousands of recording sites have been moved outwards in their respective urban areas.
GISS illustrating typical urban T data with a step due to outward site move – before adjustment.
Hit the link. Take a read. It ought to be straight forward to show if they did, or didn’t, do the adjusting right. My money would be on “didn’t” as most folks in “climate science” seem to think 20 hectares of tarmac is the same as a grass field… and move the thermometers to paved airports over time…
I demonstrated this kind of effect in the Marble Bar posting where I showed how splicing together the local series gave a “warming” similar to GIStemp results; yet the prior high temperature record had never been matched…
IMHO, “It’s all about the splice”… (and the tarmac…;-)