Friday, November 27, 2009

Lucia David Wratt responds to Ian Wishart on NIWA climate data [UPDATED]


Some points for your readers:

First, regarding data - NIWA climate data are available to anyone who registers, through the Web. Also, we provided the homogenised NZ temperature time series for the 7 sites used in forming the NZ time series to a member of the NZ Climate Science Coalition in July 2006. This is presumably the data used in the paper collated by Richard Treadgold and released by the Climate Science Coalition earlier this week.

Second, regarding information - We have written and published papers on data homogenization. We have written and published papers on NZ temperature trends. We have responded to internet blogs (Climate Audit), and newspaper letters, and to NZ Climate Science Coalition members at various times in the past regarding data homogenization, and in particular the Wellington temperatures.

Then three years after we provided the data but one week before the Copenhagen climate meeting: Allegations are spread around the internet and through press releases that NIWA scientists are fudging data. These allegations are based on an unrefereed article which ignores all of the best-practice guidance in the literature and the common knowledge about the need to account for site changes (including Wellington), That (to put things mildly) really annoys me. So do inferences that NIWA has restricted data access. But the claims of the Treadgold paper appear to be unquestionably accepted by yourself and most of your correspondents.

Regards – David Wratt

Posted by: David Wratt | November 27, 2009 at 03:09 PM

Our own Mr Tips, being a humble man, probably not thinking this this exchange warranted a blogpost, wrote the following reply to David Wratt.

Dear David Wratt

As a fellow scientist I have to say I am shocked at your attitude and methods.

1) You can move your temp. stations, that is fine. But you cannot merely "adjust" data from different locations to suit, what is at best, an educated guess. If Kelburn moved in 1927, you can only use data from 1927 on. Anything else is fiction and inaccurate.

2) If NIWA have moved other weather stations and made similar adjustments, as you call them, then the entire adjusted NZ data serious is rightly called into question. Temperature is what it is; it should not require "adjustment" and only data from the SAME weather station site can be compared with other sites.

3) Your willingness to engage in adjusting, and then defend it through "peer review", is extremely disturbing. And you shouldn't be so sensitive: like myself, you are paid by public taxpayer money, it is THEY who own the data.

I am not a climate scientist, but this is not about climate science per se. Any scientist worth their salt will tell you that the data adjustments you are making is, a priori, invalid and unacceptable manipulation.

Let the raw data speak without a muzzle please.



To date, David Wratt has not responded. Maybe he hasn't figured out how the multiple page thing works on TBR. I know it surprises me as I normally don't notice it until I realise I can't find the most recent comment.

UPDATE 28 Nov, 8:51am: The TBR thread is active again. David Wratt responds and is demolished.

Related Link: NIWA's explanation raises major new questions, Page 2 of comments, The Briefing Room

3 comment(s):

ZenTiger said...

What puzzles me is that the adjustment appears to be based on the sole criterion of altitude.

Are there NO OTHER factors to consider when "adjusting" temperatures between different weather stations??

Gooner said...

Yes there is one other factor Zen: money. Especially if you're receiving money from politicians to produce data they want to see.

Huifang said...

Dear Dr Wratt

Forgive me if I do not reveal my identity, but I am well versed in the issues of long term monitoring and data quality. I appreciate that the NZ record has been adjusted according to standard and approved methods, but from my knowledge of those methods, they are not exactly what one would call ideal. Secondly, New Zealand has a considerable number of uncontaminated sites that the long term record can be derived from. so why why why would you and Jim use the contaminated sites which then undergo the homogenisation. If I were trying to ascertain the real NZ record, I would have used the uncontaminated sited, and certainly I would have excluded Wellington. You might like to look at the records for Hamner, Coleridge, Greymouth for example. they do not suffer the problems that Wellington does. Regards

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