NIWA issued a response statement regarding the charges leveled by The NZ Climate Science Coalition here:
http://www.niwa.co.nz/our-science/climate/news/all/niwa-confirms-temperature-rise
They say:
Warming over New Zealand through the past century is unequivocal.
NIWA’s analysis of measured temperatures uses internationally accepted techniques, including making adjustments for changes such as movement of measurement sites. For example, in Wellington, early temperature measurements were made near sea level, but in 1928 the measurement site was moved from Thorndon (3 metres above sea level) to Kelburn (125 m above sea level). The Kelburn site is on average 0.8°C cooler than Thorndon, because of the extra height above sea level.
I’m not too impressed, especially when you see where the weather station for National Institute of Water and Atmosphere (NIWA) is, right on the rooftop next to the air conditioners:
Here is the station survey: NIWA_station_survey (PDF) and the Google Earth KML file
Thanks to: Dieuwe de Boer who did a good portion of station surveys in New Zealand last year.
The NZ Climate Science Coalition responds:
NIWA’s explanation raises major new questions
The NIWA climate controversy took a new twist tonight with the release of new data from the government run climate agency.
Reeling from claims that it has massaged data to show a 150 year warming trend where there isn’t one, NIWA’s chief climate scientist David Wratt, an IPCC vice-chair on the 2007 AR4 report, issued a news release stating adjustments had been made to compensate for changes in sensor locations over the years.
While such an adjustment is valid, it needs to be fully explained so other scientists can test the reasonableness of the adjustment.
Wratt is refusing to release data his organisation claims to have justifying adjustments on other weather stations, meaning the science cannot be reviewed. However, he has released information relating to Wellington temperature readings, and they make for interesting reading.
Here’s the rub. Up until 1927, temperatures for Wellington had been taken at Thorndon, only 3 m above sea level and an inner-city suburb. That station closed and, as I suspected in my earlier post, there is no overlap data allowing a comparison between Thorndon and Kelburn, where the gauge moved, at an altitude of 135 metres.
With no overlap of continuous temperature readings from both sites, there is no way to truly know how temperatures should be properly adjusted to compensate for the location shift.
Wratt told Investigate earlier there was international agreement on how to make temperature adjustments, and in the news release tonight he elaborates on that:
“Thus, if one measurement station is closed (or data missing for a period), it is acceptable to replace it with another nearby site provided an adjustment is made to the average temperature difference between the sites.”
Except, except, it all hinges on the quality of the reasoning that goes into making that adjustment. If it were me, I would have slung up a temperature station in the disused location again and worked out over a year the average offset between Thorndon and Kelburn. It’s not perfect, after all we are talking about a switch in 1928, but it would be something. But NIWA didn’t do that.
Instead, as their news release records, they simply guessed that the readings taken at Wellington Airport would be similar to Thorndon, simply because both sites are only a few metres above sea level.
Airport records temps about 0.79C above Kelburn on average, so NIWA simply said to themselves, “that’ll do” and made the Airport/Kelburn offset the official offset for Thorndon/Kelburn as well, even though no comparison study of the latter scenario has ever been done.
Here’s the raw data, from NIWA tonight, illustrating temp readings at their three Wellington locations since 1900:
What’s interesting is that if you leave Kelburn out of the equation, Thorndon in 1910 is not far below Airport 2010. Perhaps that gave NIWA some confidence that the two locations were equivalent, but I’m betting Thorndon a hundred years ago was very different from an international airport now.
Nonetheless, NIWA took its one-size-fits all “adjustment and altered Thordon and the Airport to match Kelburn for the sake of the data on their website and for official climate purposes.
In their own words, NIWA describe their logic thus.
- Where there is an overlap in time between two records (such as Wellington Airport and Kelburn), it is a simple matter to calculate the average offset and adjust one site relative to the other.
- Wellington Airport is +0.79°C warmer than Kelburn, which matches well with measurements in many parts of the world for how rapidly temperature decreases with altitude.
- Thorndon (closed 31 Dec 1927) has no overlap with Kelburn (opened 1 Jan 1928). For the purpose of illustration, we have applied the same offset to Thorndon as was calculated for the Airport.
- The final “adjusted” temperature curve is used to draw inferences about Wellington temperature change over the 20th century. The records must be adjusted for the change to a different Wellington location
Now, it may be that there was a good and obvious reason to adjust Wellington temps. My question remains, however: is applying a temperature example from 15km away in a different climate zone a valid way of rearranging historical data?
And my other question to David Wratt also remains: we’d all like to see the metholdology and reasoning behind adjustments on all the other sites as well.
I’m becoming more convinced that the mere act of opening and closing stations can introduce issues. Neglecting to ever run an overlap period, microsite issues, UHI – all serious. But I don’t see any correction for the full amount of “Station Closure Anomaly Adjustment” in the code we’ve got.
Picture the US for an instant, and pretend we have only seven stations (these are fake yearly anomalies in C).
Seattle: -1
Spokane: +5
Missoula: -4
Bismark: +3
Chicago: -1
Buffalo: -4
NYC: +2
If you’re just averaging, you’ll get zero. If you’re calculating gridcells, it is obviously more complex. Pretend for a second that this is one dimensional, and that these seven cells are the only ones used. So, in this simplified gridcell arrangement, you also get zero.
But what happens when, say, Missoula goes offline?
There’s the direct effect: the average is going to shift upwards by (+4/7).
But there’s also the gridding effect: We still have seven cells, but we have no reading for Missoula. How can we get a reading for Missoula? Well, the preferred technique is to find the two nearest know values (Spokane and Bismark) and interpolate. That would make an estimate of 4C for Missoula.
So the effect of dropping a local minima isn’t (4/7), it will be (8/7). The numbers I’ve used are made up – but what happens when you drop the only station in a section of the Rockies?
Fundamentally, this is saying that opening and closing stations directly affects the calibration of the instrument you’re using to determine “US Surface Temperatures.” You can have perfect siting and measurement across North America where every individual thermometer shows a completely flat century trend – and yet have an overall substantial increase or decrease based entirely on dropping (for whatever reason) the correct stations.
The very approach of calculating “US Average Surface Temperatures” from ground based thermometers has issues as implemented.
“Wratt is refusing to release data his organisation claims to have justifying adjustments on other weather stations, meaning the science cannot be reviewed.”
which is in direct contrast to:
“NIWA scientists are committed to providing robust information to help all New Zealanders make good decisions.”
What more can you say?
“Warming over New Zealand through the past century is unequivocal.”
Yup…
If they had a reasonable explanation for what they were doing, then those reasonable reasons would not have been produced only after they are caught diddling the numbers according to ‘internationally accepted standards’.
Lodging the weather station next to the AC blowers only demonstrates the utter lack of seriousness with which they treat their responsibility for accuracy and honesty.
Anyone involved in the leadership of the aGW movement, particularly as they get closer and closer to the IPCC, under scrutiny, will prove to be a bad player by the time this is fully exposed.
Rob,
SImply being honest, and showing that data series have windows of accuracy,
would be far too honest of an approach for cliamte scientists.
AGW: The more you know, the more you know you have been had.
AGW: the theory that does for climate science what Lysenkoism did for biology!
Correct me if I’m wrong here, but wouldn’t more thermometers actually give a more accurate reading of what is happening?
For example. Instead of moving the temperature station from where it was at and adding another one actually improve accuracy? After all we are talking about “global” warming. So maybe I just don’t fully understand, but it seems to me the more thermometers they have the more chance they have of actually being accurate.
Bin the dataset then, there are longer uninterrupted ones for NZ (which show no warming I gather)
There is a lot more to go on this story yet. On 27/11/09 Minority party leader, and coalition government Minister, Rodney Hide, requested full details of all data, code, etc from climate minister, Dr. Nick Smith. You can see the full letter at local blog site http://whaleoil.gotcha.co.nz/. Acknowledgement to local blogger, Whaleoil for this post.
Rodney Hide is not a man who is easily fobbed off. He is well known for his effective ‘crusading’ skills. He is also well educated and very articulate. Now that this request is in the public domain it will not easily be dismissed.
I guess all the other sites were moved up in elevation as well.
Yeah. That’s the ticket.
They were all moved.
Wratts Up With That?
I know this is a little OT but I’m really worried.
Has anybody noticed google has removed any search suggestions relating to the AGW scandal? I actually noticed this today because I now have to type in my entire search string. I found someone who actually posted on this.
http://www.smalldeadanimals.com/archives/012721.html
This has me very worried given googles massive control over information flow.
“The Kelburn site is on average 0.8°C cooler”
Where is the science and data for that? Where are the “peer reviewed” papers?
“internationally accepted techniques”
Likely errant code for “CRU and everyone else on the warming dole.” Have these “techniques” or tricks been revealed in “peer reviewed” papers/
They had to move it up the hill. They were predicting a 122m rise in sea levels. 😉
Mounting anemometers on buildings would also appear to distort the results. See:
Modelling of the Performance of a Building-Mounted Ducted Wind Turbine S J Watson, D G Infield, J P Barton and S J Wylie, Journal of Physics: Conference Series 75 (2007) 012001 doi:10.1088/1742-6596/75/1/012001
In New Zealand we have a version of the FOIA it’s called the official information act 1982
http://www.legislation.govt.nz/act/public/1982/0156/latest/DLM64785.html
Would it be worthwhile me testing the waters to see if I can get the data released under the act?
“Correct me if I’m wrong here, but wouldn’t more thermometers actually give a more accurate reading of what is happening?”
All the science and scientist nervousness indicates straight readings of thermometer records do not give them the warming they want. Thus the resort to adjustments, treemometers and other supposed proxies for temperature change.
To believe NIWA’s excuse of correcting for measurement station movement, you’d have to believe that it was just an amazing coincidence that all the stations moved in just such a way over the decades so as to cancel out all the warming that was simultaneously taking place and leave an amazingly flat record in the uncorrected raw data.
Yeah, that’s the ticket.
Hi Ya Viv!
Thanks to ClimateGate, we now all know what these ‘internationally accepted techniques’ look like, and we all know what ‘internationally accepted’ stands for.
Lying in order to get trillions in grant money and rule the world has been an international standard since Biblical times.
Wiki has an overview here: http://en.wikipedia.org/wiki/Official_Information_Act_1982
Although I’ve become a bit suspect of Wiki recently.
So Dr Wratt has mentioned the changes in Wellington (Where I live) what about the rest of New Zealand?
Just call me stupid, but one thing i dont understand that if station no1 and 3 are equal (words of niwa) and you would leave out station 2 (just fill in 999 for every measurement 🙂 ) then you would see no warming. In stead they made the adjustments like a upward sloping line.
Another summing up story on the UK Telegraph
http://www.telegraph.co.uk/earth/copenhagen-climate-change-confe/6672875/Whos-to-blame-for-Climategate.html
In addition to the ‘weather geek’ station surveys (visible & IR photos, Lat/Lon/Altitude, interviews and such), I think it prudent to start asking about temperature sensor calibration. How frequently calibrated? Gain & offset values vs time? Method of calibration (e.g. ice-bath & boiling water method)? External test equipment used in the calibration? Calibration of the External Test Equipment (as we in the colonies call ‘NIST Traceability’ … I should be able to construct a paper-trail from the 1-deg C measured here in Arizona all the way back to the NIST 1-deg C in Washington DC, etc)
Oh! I though that the Internationally accepted technique to adjust temperatures was to use tree rings and readjust the temperature of real thermometers. So, what they really should have done is cut a tree at Kelburn and another at Thorndon and do the Mann trick… Et Voila!
So does this mean there was no TOBS correction?
Rodney Hide is also scientifically trained. He has a bachelor degree in zoology and a masters (MSc) in resource management.
http://www.parliament.nz/en-NZ/MPP/MPs/MPs/7/6/1/49MP11981-Hide-Rodney.htm
“The Kelburn site is on average 0.8°C cooler than Thorndon, because of the extra height above sea level.”
This isn’t science. There is no “average” based solely on altitude, an average of locations within an air column in a specified time span would not necessarily be the same average of those same points in a different time span. Especially with accuracies and concerns are considered in increments of tenths of a degree, this is pseudoscience, no better than guessing.
Why not just have one station for the world, and determine temperatures for every location on the earth, by an average lapse rate! Were there only one, “the best we could do” would not make it scientific or reality. This adjustment stuff can only be carried so far.
There is in fact a perfectly standard way to handle this problem. Use a third station which overlaps both the old and new stations, and adjust the old so it has the same difference from the third station as the new.
Doing it in this order may not at first seem logical but it avoids having to continuously adjust the new station.
Given that long-term relative temperatures do not vary much over distances of 10s, or even 100 of kms, this method is perfectly sound. If the distance is of the order of 100s of km then it should be done separately for each calendar month.