As noted before, climateaudit readers have helped UCAR find the lost civilization of Chile and today, we are happy to report that we have helped NASA find the lost city of Wellington NZ.
NASA’s records for Wellington NZ were mysteriously interrupted in 1988 – an interruption so severe that we assumed that Wellington NZ must have been destroyed by Scythians. We are happy to report that Wellington NZ is still in existence.
This is not the only good news. We are also happy to announce that there is still a functioning meteorological service. Not only that, but can announce contact with the indigenous representatives.
Although NASA (and NOAA) appear to have lost contact, an indigenous NZ climate scientist familiar with the lost records has contacted climateaudit. I have passed this exciting news on to NASA and urged them to restore contact with their lost cousins in NZ.
Previously, we had shown the following graphic showing the termination of NASA records in 1988 and the adding of a substantial trend to the Wellington NZ record in the Hansen adjustment.
David Wratt of NIWA, the indigenous New Zealand meteorological authority, wrote to CA as follows:
It is time to put on record “ once again “ what some contributors here already know: Fitting a linear trend to the entire unadjusted NASA GISS plot for Wellington is physically meaningless. This is because as time progresses this unadujsted plot uses measurements from different sites at different altitudes.
Much of the data used by GISS comes from the site at Kelburn, which is in a park at about 125m above sea level. This data set does not start until January 1928. Before this, the Wellington measurements were taken much closer to sea level. For example from July 1912 until December 1927 they were from a site in Thorndon, at 3m above sea level. As you know, there is a drop off of temperature with height which occurs (on average) in the atmosphere.
We have made this point already to some people who continue to publicly misinterpret the unadjusted NASA GISS plot for Wellington in this way.
I should also mention here that there is a further data set from measurements 4 m above sea level at Wellington Airport, commencing in January 1962.
To find the real trend, you must make appropriate homogeneity adjustments which take account of the differences in height between the various measurement series and also use the time when the Kelburn and Wellington Airport temperature series overlap. When you do that, you will find a long-term warming trend for Wellington through the 20th century.
It is interesting that NIWA should be so alert to perceived mis-steps at Climate Audit and yet have never taken the time to inform Hansen that he has erroneously failed to update his NZ records or, as we shall see below, to question Hansen’s “adjustment” of the Wellington records. Although Wratt commented that fitting a trend to the NASA unadjusted record was “meaningless”, I note that he did not comment on whether there was any meaning to the “NASA adjusted” record. I presume that this was out of “professional courtesy”.
Separately, Warwick Hughes emailed me that New Zealand station records could be downloaded from here , a service which has been free since August 2007. The data seems to be available only in an inquiry form, so scraping will be required at some point. I manually checked Wellington NZ and obtained information for the following 7 separate identifications:
Wellington, Kelburn Aws 25354 -41.285 174.768 125 G Metsrvice
Wellington High, D Pk 3382 1427H -99941.263 174.784 120 G N/A
Wellington, Knowles Ob 3383 E14270 -99941.283 174.783 27 W N/A
Wellington,Kelburn 3385 E14272 -99941.286 174.767 125 G Metservice
Wellington,Bowen St 3389 E14276 -99941.283 174.783 18 W N/A
Wellington,Thorndon 3391 E14278 -99941.283 174.783 3 W N/A
Wellington,Karori 3392 E14279 -99941.284 174.737 152 G N/A
Wellington,Buckle St 3431 E14370 -99941.300 174.783 34 W N/A
Wellington Aero 3445 E14387 -99941.322 174.804 43 G N/A
Here is a first cut comparison of the two NASA series (black) to the 7 NIWA series (red.) A couple of immediate observations:
the GHCN-NASA “raw” record is not the same as any of the NIWA records, so some sort of unreported combining of stations has already taken place in the GHCN-NASA “raw” record
there are indeed NZ records more recent than GHCN-NASA’s 1989 termination
Parsing the records in detail, here are some specific comparisons of GHCN-NASA versions to NIWA versions. The figure below shows that the GHCN version 507934360010 is pretty much identical to Kelburn 3385 from 1928 to 1970. However, the GHCN version has values prior to 1928 and it differs from the Kelburn version after 1970.
Next here is a comparison of a short GHCN version 507934360011 to Kelburn 3385. These two versions are essentially identical for the period 1970 to 1980. Thus we have the odd situation, where GHCN-NASA switches provenance from Kelburn to some other station in 1970 (and I can’t identify the other station so far) and puts the continuing Kelburn station as a different version. Bizarrely, Hansen will then calculate a “Hansen-bias” between the two on the basis that the 1970-1980 portion of version 0 is the continuing Kelburn series, whereas the 1970-1980 Kelburn series is in the other version 1. One sometimes gets a little dizzy.
For some inexplicable reason, Kelburn 3385 after being a continuous record since at least 1928 is discontinued under that identification in August 2005. A new station Kelburn Aws 25354 has a short overlap and is within a tenth of a degree in the overlap. As a quick representation of Wellington, here is a plot of the GHCN-NASA version (black) against the average of Kelburn 3385 and Kelburn Aws 25354.
Update: Nov 2009, NIWA adjustments:
What can we conclude from this? First, GHCN has combined stations that are not homogeneous. NIWA says that, properly homogenized, the stations show a warming trend. One would certainly expect that. Indeed, there’s no doubt in my mind that the late 20th century is warmer than the 19th century. But why is GHCN-NASA using different stations as though they are one? And in this case, why is one version split into two parts and then a different station spliced into version 0 – what a mess. Where did the early portion of the NASA record come from?
And something that the NIWA spokesman did not comment on: what of the Hansen adjustment? The NIWA spokesman, said with an almost Gavinesque sigh, that
It is time to put on record “ once again “ what some contributors here already know: Fitting a linear trend to the entire unadjusted NASA GISS plot for Wellington is physically meaningless.
However, he didn’t comment on the NASA adjusted version. If one is allowing for urbanization in Wellington for the period since 1928 (presuming a non-homogeneity at 1928) to the present, then there is no physical theory under which the adjustment should reduce earlier measurements as Hansen has done. Exactly how Hansen’s algorithm effected this reduction still remains somewhat of a mystery (which we are working on). Whether this particular Hansen error, whatever it is, creates an overall bias also remains to be determined. But the adjustment makes no sense in this particular instance, so there is obviously something wrong somewhere. It would be nice if, just for once, someone like DAvid Wratt of NIWA, could simply agree about something like this.