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.
However, without no overlap data between Thorndon and Kelburn, we can’t use it.
=================
You can, but you have to make an assumption.
1. No increase or decrease of temperature
2. Extrapolate at the delta of A
3. Backcast at the delta of B
4. Interpolate at the average of A and B
There is something to be said for 1 and 4.
It’s back to one of the main flaws in the Alarmist strategy.
1. Compute absolute temperatures using fiddles.
2. Now calculate the change based on that fiddled data.
3. Now further maniplate the data via models etc.
Instead, keep it very simple. Go and look directly at the change and ignore the absolute temperatures. Use as many sites that meet a quality threshold. If desparate introduce a propert UHI adjustment.
Nick
John Moore (09:14:25) :
However, without no overlap data between Thorndon and Kelburn, we can’t use it.
Glenn, you write “if the thermometers were .2C different tomorrow from what it was today, and some guy came along and said no, because of the average lapse rate, the thermometers were really .6C different” – ys, if that was the case. But we are dealing with .2C a difference between two thermometers, at different locations, on different days? I don’t see any way to use that information.
But you do see a way to use a lapse rate that doesn’t work even with some known stations in the area? I’m bafflegasted. Yes, my example has two thermometers at different locations and altitude, with temperatures compared from Dec31 and Jan1. If the lapse rate held water, these two should be separated by .8C instead of .2C. And despite the fact that they are different days, as I said, the actual temp data of the two stations did not diverge by .8C for four years, two earlier years of seasons and days, and two later years of seasons and days.
This does not occur on the graph between Kelburn and the “Airport”, and at no point are they different by only .2C. The closest is 1970, when they were about .4C apart. But look at the adjusted graph; the end of Thorndon and start of Kelburn are .6C apart, much less aligned than in 35 years between Kelburn and Airport.
Well, I’m thoroughly confused.
First:
“I’m bafflegasted. Yes, my example has two thermometers at different locations and altitude, with temperatures compared from Dec31 and Jan1. If the lapse rate held water, these two should be separated by .8C instead of .2C.”
How do you arrive at that? Without using additional information, you can’t say with accuracy of even a few degrees about how the temperature on Dec31 and the temp on Jan 1 are related. What am I missing?
Nick writes:
“Instead, keep it very simple. Go and look directly at the change and ignore the absolute temperatures. Use as many sites that meet a quality threshold. If desparate introduce a propert UHI adjustment.”
If we are only talking about Wellington, which is subject of the (IMHO) improper allegation of misconduct, then my #1 argues against “look directly at the change.” If we are talking about lots of stations, then I agree that using deltas is fine (and probably more reasonable), for aggregates, than trying to construct continuous station time series – ASSUMING that nothing changes in any series over which you take the aggregate – such as time of observation, etc. That is a huge assumption, as the discussion on Darwin Zero demonstrates. However, if we are talking aggregates, than the assertion of misconduct in Wellington fails, because obviously Wellington is an example of constructing a single time series, and as far as I can tell, a quite reasonable one.
” the actual temp data of the two stations did not diverge by .8C for four years, two earlier years of seasons and days, and two later years of seasons and days.”
If the two stations have no overlap, how can you say this?
“This does not occur on the graph between Kelburn and the “Airport”, and at no point are they different by only .2C. The closest is 1970, when they were about .4C apart. But look at the adjusted graph; the end of Thorndon and start of Kelburn are .6C apart, much less aligned than in 35 years between Kelburn and Airport.”
We were discussing Thorndon and Kelburn in the lapse rate discussion, not Kelburn and airport.
Let’s step back for a moment and look at their explanation:
Kelburn is 120m higher than Airport, and, no surprise, is about .8C cooler during the time their records overlap. This .8C is, by definition, the environmental lapse rate between those two sites, and is consistent with the earth’s average environmental lapse rate of 6.8C (which gives .816C delta). Hence we have measurement of the lapse rate, and a reasonableness check on that (the lapse rate calculation).
Now, we go to Thorndon. Thorndon does not overlap either time series in the data provided. So what are we to do with it? We can’t just toss it in unadjusted as the front of the time series – that would bias the trend downward when the Kelburn vs Airport delta, and the lapse rate delta, both argue for decreasing the Thorndon temp by around .8C. And voila – that’s what the NIWA did. So what in the world is the crime?
Is the issue is the adjustment decreasing the airport by that amount, as is done in the ,a href=”http://www.niwa.co.nz/our-science/climate/news/all/niwa-confirms-temperature-rise/combining-temperature-data-from-multiple-sites-in-wellington”>NIWA graph at http://www.niwa.co.nz/our-science/climate/news/all/niwa-confirms-temperature-rise/combining-temperature-data-from-multiple-sites-in-wellington ? If so, why? Over the time of overlap, the two are highly correlated. Hence it really doesn’t matter whether you adjust airport, or just throw it away – you get the same result.
If you didn’t have Airport, you would be stuck with two disjoint series, that are from different places and importantly, at different altitude. There are two ways to use those:
1) compute the trends separately – which gives you a trend from 1913 or so to 1927, and a separate trend from 1927 to the present. The problem with this is it doesn’t tell you ANYTHING about the trend from 1913 to the present. In this particular case, that isn’t a huge deal, since we are only losing 13 years, but in other cases, it could be really significant.
2) combining the two records, with the adjustment. Only by failing to adjust Thorndon does that 14 years count, because now you are adding in what is pretty clearly data that is way too warm. While we cannot know with accuracy what that adjustment should be, we have a reasonable guess – based on the two factors: the airport/kelburn delta, and the average environmental lapse rate.
2) combine the trends. See #1
Wellington’ newspaper The Dominion, 15 Dec 1927, states:—“Kelburn.—We are now getting records from both stations,’ said Dr. Kidson (former direcor of NZ meteorological service), ‘so that some idea of the difference in conditions may be ascertained.’ From the beginning of the year (1928) the station at Thorndon will be abandoned.” This change is being made because the Railway Department requires the site at Thorndon.”
Why is nobody asking Niwa for these records?
Sorry, guys, my comment got out of order. In order to understand the start, you need to look at the ends. This little tiny comment box is not really set up for writing essays 😉
John Moore (13:47:09) :
“Well, I’m thoroughly confused.
First:
“I’m bafflegasted. Yes, my example has two thermometers at different locations and altitude, with temperatures compared from Dec31 and Jan1. If the lapse rate held water, these two should be separated by .8C instead of .2C.”
How do you arrive at that? Without using additional information, you can’t say with accuracy of even a few degrees about how the temperature on Dec31 and the temp on Jan 1 are related. What am I missing?”
**************
Actually with the data extracted from the unadjusted graph we can see that Kelburn was nowhere near .8C lower than Thorndon for a period of YEARS. The chart shows averages, to answer your question. The average for two years before Thorndon closed is steady at about 13.0C. Kelburn opened at about 12.8C, and wasn’t cooler than .79C (12.2C) till over a year later.
But you didn’t comment on the argument about any point on the graph of Kelburn and Airport being always around .79C different. Why is the point where Thorndon closes and Kelburn begins not at or close to .79C?
***************
“Kelburn is 120m higher than Airport, and, no surprise, is about .8C cooler during the time their records overlap. This .8C is, by definition, the environmental lapse rate between those two sites, and is consistent with the earth’s average environmental lapse rate of 6.8C (which gives .816C delta). Hence we have measurement of the lapse rate, and a reasonableness check on that (the lapse rate calculation).”
**********
Why is it reasonable to assume the .79C difference in stations is a result of lapse rate?
I’d suspect that temps taken around airports would be warmer than in the middle of the Botanical Gardens. It only seems “consistent” because that is the value NIWA used, and it happened to match fairly well.
The Wiki article you quoted before shows a lapse rate of 6.49C/1000m, not 6.8C.
This works out to be the exact figure needed to compute the lapse rate of 121 meters, that the “Airport” station was lowered by .79C, not .81C. In addition to that, the “Airport” is a record of multiple stations, the most recent I suspect as being the one that is hotter by .4F than the other airport location.
“Kelburn opened at about 12.8C, and wasn’t cooler than .79C (12.2C) till over a year later. ” –
But – it *was* cooler a year later, and a lot of other years. Why wasn’t it cooler right on that day, by the lapse rate? Lots of reasons. The lapse rate is an average. Maybe that time of year there are frequently low clouds, which would reduce the lapse rate. Maybe… lots of maybes
“I’d suspect that temps taken around airports would be warmer than in the middle of the Botanical Gardens.”
That depends on lots of factors, just like everything else in this data. Airports in 1927 may have been pretty green and cool. When I was learning to fly, I used a number of grass airstrips.
Airports these days are bigger and more likely to have a lot of concrete and asphalt. So looking back at where those two series almost connect, the airport is not likely to have yet been experiencing UHI effect and most likely didn’t have asphalt runways.
Also, I was unaware that “Airport” was a bunch of stations. Does that mean one station moved around and changed, or a bunch operating at once? Normally, the “airport” temperature is that of some official gauge at an airport, not a bunch of stations, although it changes from time to time (as evidenced from the official reasons for the Darwin station adjustments).
But if you can point me to more details about Wellington AP, I’d look.
Here is my take… I wandered into this discussion after seeing some claims that the Wellington data were clear evidence of malfeasance and bad-faith adjustments. I looked at the posts, especially the graph that is so prominent, and quite the contrary, they looked pretty darned reasonable, from what was presented.
They still look reasonable. So if there’s some reason they are not unreasonable, it must be in data beyond that graph and the little goodie put out by NIWA explaining it all, or we are simply in disagreement about how to interpret all this.
So… are you making your observations based on the same information I’m looking at, or is there more information you are using?If the latter, I’d love to know about it.
John Moore (17:13:28) :
“But – it *was* cooler a year later, and a lot of other years. Why wasn’t it cooler right on that day, by the lapse rate? Lots of reasons. The lapse rate is an average. Maybe that time of year there are frequently low clouds, which would reduce the lapse rate. Maybe… lots of maybes”
All I can tell you is that virtually no two points between Kelburn and Airport show more than a .2C relative difference, in over 500 monthly averages. These points do not represent a single day, the chart resolution allows at best a “point” of perhaps a month’s averaged temperature. You’re hung on a “day”, I don’t know why. I provided the specific open and close dates to show there should be no data gap.
Test it – look at the graph, there are virtually no “points” at Kelburn in one month of more than .2C difference to a “point” at Airport in the next month. This is easier to see in the adjusted graph because the two records are aligned (not to mean that adjustment is valid). Check it yourself!
Another way to look at this is to realize that a line linking the end of the adjusted record of Thorndon to the start of Kelburn would be a *vertical line* (instantly) raising temps .6C! Keep in mind that the graph is made from an average of temps, day to day anomalies are not shown. The closest comparison by my reckoning is the Airport dropping in 1962 about .9C in a *year*. But it would have been .6C cooler in an instant before Kelburn opened and stayed that way long enough to show in an averaged graph? Possible, but not probable, and not seen anywhere in the graph.
A weather fluke in 1928? Possible, but not probable to affect an averaged dataset, and not seen anywhere else in the graph.
“Also, I was unaware that “Airport” was a bunch of stations.”
If you’re interested, look at Glenn (21:05:46) in
http://wattsupwiththat.com/2009/12/06/how-not-to-measure-temperature-part-92-surrounded-by-science/#comments
Also Glenn (15:28:56)
I found a website that lists two temperature station locations at the airport, the site claiming a .4F different average between the two, station WMO Id 93439 Wellington Aero Aws and WMO Id 93436 Wellington Airport.
http://weather.gladstonefamily.net/site/NZWN
There appears to be at least three stations involved, with data merged in the database. That surely doesn’t mean the graph was plotted from merged data, even if the only indication was the lack of coverage ’92-’95. No temp data for Thorndon is available from the NIWA website, and the first 3 years of temp data for Kelburn is missing. Apparently NIWA has access to data not in the database, despite their claim that all the data is available to anyone in the database.
In these two threads there are lots of links and information. I’ve made some minor mistakes. But ask and I’ll try to help if you want more.
Glenn,
“You’re hung on a “day”, I don’t know why. ” What I am hung up on is that we do not have any overlap between Throndon and Kelburn. The “day” is the amount of gap between the two and nothing more (Dec 31-Jan 1). If we had a few years of overlap, then all of this surmising would be much less of an issue. It is because there is no overlap that the amount of adjustment becomes such an issue – the overlap would let us calibrate (as it does between Airport and Kelburn); without it, we have to go ad hoc and use something like the average lapse rate (which at least is sort-of verified by the Kelburn-Airport delta).
Okay, I think that without the monthly (or daily) data, we aren’t going to get much farther. To me, that .6C discontinuity does not look visually like a problem. Why should a .6C difference in year-to-year temperature be surprising?
Unfortunately, the graph doesn’t provide nearly enough resolution in the time scale for me to see what the real numbers are underneath it, or to resolve monthly information. The graph I am referring to – the “adjusted” one – is at http://www.niwa.co.nz/__data/assets/image/0009/99693/varieties/flash.jpg .
Try this experiment: make the lines the same color, and draw line from the end of Thorndon to the start of Kelburn. I suspect things would not look at all shocking. If I had the data, I’d plug this stuff into Excel and sort this all out and do the graph.
I apologize for not following your analysis of “there are virtually no “points” at Kelburn in one month of more than .2C difference to a “point” at Airport in the next month.” but I can’t read the graph to a monthly level, and if those are yearly averages, we have to understand the averaging process in order to know how they handled the ends of the two time series (running averages have a problem with ends).
The lack of data that you mention at the end is annoying – it may prevent us from being able to analyze this adequately. It does make one wonder how they can draw the graphs with no missing years, when they have no Throndon data and miss the first 3 of Kelburn. That would be a good question to ask them, but I’d bet that at the moment, they are being bombarded with questions about all of this.
I hope that, rather than just shut everyone out, they take whatever they have, in whatever form, and put it out on the web. Otherwise this will just keep on simmering. Ultimately, one good that will come out of this is that people with climate data will be required to make it *all* available, all the time. If nothing else, so they won’t have to respond to a blizzard of requests.
If you can find better data than that darned graph, I’d love to get it.
I appreciate your participation in all this.
John Moore (21:27:38) :
“Okay, I think that without the monthly (or daily) data, we aren’t going to get much farther. To me, that .6C discontinuity does not look visually like a problem. Why should a .6C difference in year-to-year temperature be surprising?”
Not year to year, if we assume there was no break in coverage. The .6C could not be a one day anomaly, if the adjusted graph accurately depicts temps, Kelburn at open would have *instantly* and for an extended period of time experienced and maintained that amount of increase. It would have had to, to show up in an averaged dataset. It’s too much to expect. And there is no comparable occurrence seen at any time in the 90+ year record of Kelburn. The average drops fast a few times, in periods of year to year, but not in one day! How the data was averaged has no bearing on this. If anything, the problem is only magnified by the scale of the graph.
Were the adjustment accurate, I’d expect to see the end and beginning of the plot lines connect, were there no gap in coverage. Can you explain why they would not?
The whole business is frustrating. In the time NIWA took to respond and accuse interested parties no doubt similarly frustrated, they likely could have just made the actual data available online, with a simple explanation of what data was used, when and where it came from, and some methodology. Instead, they issue what really looks to me like a trick at least with the Wellington reconstruction. The “Airport” is dropped to match Kelburn, so that it looks like an altitude adjustment is valid. They then drop Thorndon the same because Kelburn and the Airport matches so well with the altitude adjustment, and provide no other justification that I’ve seen. They leave a little gap of about a year between Thorndon and Kelburn, with no reason, but state the dates of close and open, which is a day, not a year apart.
It conveniently produces a nice upward trend, though. IMO this all invites skepticism.
Yes, I can. If those are annual averages (Jan1-Dec31), then the graph is saying that the last year of Thorndo was .6C cooler than the first year of Kelburn, which is completely reasonable. And, the graph is clearly of averages, because the curve is way too smooth for daily data.
I don’t think it’s a trick. Unfortunately, because I don’t have anything better to go on than that graph and their explanation, I can’t judge it very well.
Yeah, that makes no sense at all.
I just found their temp data site. Back after I’ve done some plotting.
Cheers
Another example of altitude adjustments not always working:
“Auckland is another example where the assumption is unsupported. Albert Park is at
49 m, and Mangere is at 2 m. Theoretically, Albert Park should be colder by about 0.3ºC.
The opposite is true. On average, Mangere was 0.65ºC colder than Albert Park over the
1962 to 1989 overlap period. That means the error is almost a full 1ºC!”
http://nzclimatescience.net/images/PDFs/si_hokitika_301109.pdf
Okay, here’s what I found…
It looks like their graph in their explanation is based on simple Jan-Dec annual averages. Above it was mentioned that apparently more than one station was used to construct the airport data, and that appears to be true. I just used one and didn’t bother to search for the rest.
There is no 1 year gap – Thorndon 1927 mean is 14.0, while Kelburn 1928 is 12.8.
My resulting plot is at
http://www.tinyvital.com//images/WellingtonAnnualTempData.png
I can’t put my data out there because of their usage agreements, but it is available from their data center at: http://cliflo.niwa.co.nz/
Your statement “All I can tell you is that virtually no two points between Kelburn and Airport show more than a .2C relative difference, in over 500 monthly averages.” appears to not apply, because we are looking at annual averages. For annual averages, the data set does contain inter-annual differences of >= .6C (for example, Kelburn 1981:13.1, 1982: 12.4 delta: -.7c)
Typo Correction, Thorndon 1927 mean is 13.0
John Moore (11:08:48) :
“If those are annual averages (Jan1-Dec31), then the graph is saying that the last year of Thorndon was .6C cooler than the first year of Kelburn, which is completely reasonable.”
The graph does plot yearly averages. But I believe you are looking at this wrong. If there is no gap in data coverage, then the plotted point that temps diverge from one year to the next would be the same y-axis point where Thondon ends and Kelburn begins, not a year gap between them.
The beginning of the Kelburn line, the “point” representing averaged data of a year, represents the SAME year as the last year of Thorndon.
The .6C discrepancy is NOT from a continuous record of one averaged year being .6C less than the next year, but instead brings the accuracy of the altitude adjustment itself in question.
This is why I brought the .4C difference in 1970 of the Kelburn and Airport discrepancy to your attention, that it only happened once in 45 years.
For that reason, with the Thorndon and Kelburn adjustment, it is not reasonable to assume the adjustment is accurate or reliable.
There is always the question, if you want absolute temperatures and not deltas, how much of an overlap you need.
For example, lets say the overlap is a day. Given there may be met conditions for that day that do not reflect the long term conditions, it would be a bad decision to rely on just one day.
nick
BTW… just for fun, the monthly delta across the interstation gap is huge: 2.8C – for whatever that’s worth
Thorndon Dec 1927: 14.7 (2C greater than Nov 1927 of 12.7)
Kelburn Jan 1928 11.9
So I plotted the splice here: http://www.tinyvital.com/images/WellingtonSplice19271928.png
Notice in this graph, of monthly rather than yearly averages, things look a lot different and the splice still looks reasonable ( I plotted adjusted and non-adjusted)
Glenn: “The beginning of the Kelburn line, the “point” representing averaged data of a year, represents the SAME year as the last year of Thorndon.”
I disagree. The Thorndon line does not contain any data (and hence cannot have any average over) 1928. Likewise, the Kelburn line does not contain any data from 1927. Thus the .6C delta is from 1927 to 1928. See the monthly plot I just put up (I didn’t see you post at first because I was trying the beat Excel into submission). The point that is the end of the Thorndon line is the annual average for 1927, the point that is the start of the Kelburn line is the annual average for 1928. That’s why I went and got the data myself and plotted it – was to see this.
Nick – agreed – the more overlap, the better an adjustment you can make – up to a point. One day’s overlap would not tell you much – there could be, for example, wind conditions that day that totally change the difference between the two stations. Unfortunately, in this case, using the data I downloaded (I didn’t go for the daily data – I’m taking their word for it as to the start/end dates), there is zero days of overlap. Hence there is no information available from overlap if one just looks at those two stations in isolation.
John Moore (12:51:39) :
“Your statement “All I can tell you is that virtually no two points between Kelburn and Airport show more than a .2C relative difference, in over 500 monthly averages.” appears to not apply, because we are looking at annual averages. For annual averages, the data set does contain inter-annual differences of >= .6C (for example, Kelburn 1981:13.1, 1982: 12.4 delta: -.7c)”
The NIWA graph is good enough to see what the max adjusted annual difference is in the record between Kelburn and Airport, as I already mentioned, about .4C around 1970, one time in 45 years. That is what I meant by “virtually” no two averaged years of the magnitude of .6C difference. I was aware that the graph was plotted with yearly averages, and apologize for trying to hammer my point down by stressing how many months are included in over 40 years. But my point still stands.
I’m surprised to find you managed to find the raw temp data from a source on the Internet of Thorndon and 1928, 1929 and 1930 Kelburn stations. Perhaps I wasn’t registered with the adequate “subscription level” (argent) for the NIWA database, although I can access temp data for many stations, including Kelburn after 1930.
How were you able to actually download this data?
Nick, let me add… one reason to use geographically “similar” stations is to calibrate adjustments across a gap.
John,
Your plotted graph still shows a gap of a year between Throndon and Kelburn.
If there is no gap in data, there would be no data missing for a year.
Glen writes: “Another example of altitude adjustments not always working:
That’s a straw man argument. Anyone who claims altitude adjustments always work is as far out of touch as someone who denies the 1.2C/CO2-doubling value from the 1-D radiative balance model.
Of course altitude adjustments don’t always work. We don’t even need to go looking for it – we know that UHI is but one of many factors that can cause errors.
The argument is that altitude adjustments are the most reasonable thing to do with two stations of different altitudes, IN THE ABSENCE OF OTHER INFORMATION. Our discussion on Thorndon/Kelburn fals into that category. That argument also means that the use of an altitude adjustment in that circumstance is not an argument for malfeasance or even sloppiness.
John Moore (13:54:54) :
“Notice in this graph, of monthly rather than yearly averages, things look a lot different and the splice still looks reasonable ( I plotted adjusted and non-adjusted)”
Nice graph. But why does this make the adjustment look any more “reasonable”? Your graph makes it impossible to see a real trend, but still reveals at least a .6C gap.
Wouldn’t the graph look much more reasonable if the end and start point of the two stations were the same, since they both represent the exact same time of measurement? Certainly this disparity does not support the accuracy of the adjustment for altitude, and isn’t that what this is all about?
Look at the slope of the line from the left series and how it matches, including the gap, the slope on the right. The .6C “gap” (which is a temperature difference between two different months) fits right in.
Going back to basics… what is it about that .6C gap that remains a problem?
…continuing… Without the .6C gap, the graph would look wrong – the temperature, which was rising at the end of the year (note the annual peak tends to be after the start of the year) would have to stop rising.
If we look at the annual averages, the only “problem” would appear to be that there was a .6C difference between the two years. That simply is not out of the ordinary.
I thiink we are still talking past each other somehow, but I don’t know what the missing link is. Sorry.