Guest Post by Willis Eschenbach
Anthony Watts has posted up an interesting article on the temperature at Laverton Airport (Laverton Aero), Australia. Unfortunately, he was moving too fast, plus he’s on the other side of the world, with his head pointed downwards and his luggage lost in Limbo (which in Australia is probably called something like Limbooloolarat), and as a result he posted up a Google Earth view of a different Australian Laverton. So let’s fix that for a start.
Figure 1. Laverton Aero. As you can see, it is in a developed area, on the outskirts of Melbourne, Australia.
Anthony discussed an interesting letter about the Laverton Aero temperature, so I thought I’d take a closer look at the data itself. As always, there are lots of interesting issues.
To begin with, GISS lists no less than five separate records for Laverton Aero. Four of the records are very similar. One is different from the others in the early years but then agrees with the other four after that. Here are the five records:
Figure 2. All raw records from the GISS database. Photo is of downtown Melbourne from Laverton Station.
This situation of multiple records is quite common. As always, the next part of the puzzle is how to combine the five different records to get one single “combined” record. In this case, for the latter part of the record it seems simple. Either a straight linear offset onto the longest record, or a first difference average of the records, will give a reasonable answer for the post-1965 part of the record. Heck, even a straight average would not be a problem, the five records are quite close.
For the early part of the record, given the good agreement between all records except record Raw2, I’d be tempted to throw out the early part of the Raw2 record entirely. Alternately, one could consider the early and late parts of Raw2 as different records, and then use one of the two methods to average it back in.
GISS, however, has done none of those. Figure 3 shows the five raw records, plus the GISS “Combined” record:
Figure 3. Five GISS raw records, plus GISS record entitled “after combining sources at the same location”. Raw records are shown in shades of blue, with the Combined record in red. Photo is of Laverton Aero (bottom of picture) looking towards Melbourne.
Now, I have to admit that I don’t understand this “combined record” at all. It seems to me that no matter how one might choose to combine a group of records, the final combined temperature has to end up in between the temperatures of the individual records. It can’t be warmer or colder than all of the records.
But in this case, the “combined” record is often colder than any of the individual records … how can that be?
Well, lets set that question aside. The next thing that GISS does is to adjust the data. This adjustment is supposed to correct for inhomogeneities in the data, as well as adjust for the Urban Heat Island effect. Figure 4 shows the GISS Raw, Combined, and Adjusted data, along with the amount of the adjustment:
Figure 4. Raw, combined, and adjusted Laverton Aero records. Amount of the adjustment after combining the records is shown in yellow (right scale).
I didn’t understand the “combined” data in Fig. 3, but I really don’t understand this one. The adjustment increases the trend from 1944 to 1997, by which time the adjustment is half a degree. Then, from 1997 to 2009, the adjustment decreases the trend at a staggering rate, half a degree in 12 years. This is (theoretically) to adjust for things like the urban heat island effect … but it has increased the trend for most of the record.
But as they say on TV, “wait, there’s more”. We also have the Australian record. Now theoretically the GISS data is based on the Australian data. However, the Aussies have put their own twist on the record. Figure 5 shows the GISS combined and Adjusted data, along with the Australian data (station number 087031).
Figure 5. GISS Combined and Adjusted, plus Australian data.
Once again, perplexity roolz … why do the Australians have data in the 1999-2003 gap, while GISS has none? How come the Aussies say that 2007 was half a degree warmer than what GISS says? What’s up with the cold Australian data for 1949?
Now, I’m not saying that anything you see here is the result of deliberate alteration of the data. What it looks like to me is that GISS has applied some kind of “combining” algorithm that ends up with the combination being out-of-bounds. And it has applied an “adjustment” algorithm that has done curious things to the trend. What I don’t see is any indication that after running the computer program, anyone looked at the results and said “Is this reasonable?”
Does it make sense that after combining the data, the “combined” result is often colder than any of the five individual datasets?
Is it reasonable that when there is only one raw dataset for a period, like 1944–1948 and 1995–2009, the “combined” result is different from that single raw dataset?
Is it logical that the trend should be artificially increased from 1944 to 1997, then decreased from that point onwards?
Do we really believe that the observations from 1997 to 2009 showed an incorrect warming of half a degree in just over a decade?
That’s the huge missing link for me in all of the groups who are working with the temperature data, whether they are Australian, US, English, or whatever. They don’t seem to do any quality control, even the most simple “does this result seem right” kind of tests.
Finally, the letter in Anthony’s post says:
BOM [Australian Bureau of Meteorology] currently regards Laverton as a “High Quality” site and uses it as part of its climate monitoring network. BOM currently does not adjust station records at Laverton for UHI.
That being the case … why is the Australian data so different from the GISS data (whether raw, combined, or adjusted)? And how can a station at an airport near concrete and railroads and highways and surrounded by houses and businesses be “High Quality”?
It is astonishing to me that at this point in the study of the climate, we still do not have a single agreed upon set of temperature data to work from. In addition, we still do not have an agreed upon way to combine station records at a single location into a “combined” record. And finally, we still do not have an agreed upon way to turn a group of stations into an area average.
And folks claim that there is a “consensus” about the science? Man, we don’t have “consensus” about the data itself, much less what it means. And as Sherlock Holmes said:
I never guess. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. — Sir Arthur Conan Doyle, A Scandal in Bohemia
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Thanks Willis for correcting my Google Earth mistake and making an even better post. I’ve made a note in the original post along with a link.
Nicely summed Willis. The simple point I was making in my correspondence with senior BOM climate staff is that they simply do not know the effect of UHI at this critical station, yet insist it is suitable for climate monitoring. IMHO they need to do the experiment then perhaps they can say something about UHI at the site. At the moment they are just guessing.
I was looking at writing this up and submitting to the Australian Meteorological and Oceanographic Journal but when I looked at the editorial board (see here: http://www.bom.gov.au/amm/editorial-board.shtml) I figured I might as well try the Minister.
Anthony,
I hope you have a real holiday scheduled after this trip!
Cheers
Marc
Imagine a DA bringing speeding charges against you. These are serious charges and could result in felony charges involving words like “criminal indifference to human life” or “speeding through a school zone”.
Your defense attorney asks what is the evidence.
He is informed there are six different readings from two police jurisdictions. These readings are from at least six different radar guns, all with a history of giving, on occasion, spurious results. Because of these technical difficulties, the data from these readings are combined and then homogenized. Both the specific locations of the radar units and the basis of the data adjustments are not available to the defense. In fact, they are not available to anyone, as the records storage area of the two jurisdictions are in a state of complete chaos.
In addition, the technicians responsible for making the the ‘adjustments’ use undocumented and varying procedures for these adjustments.
One technician testifies, reluctantly, regarding his experience with one of the radar locations. He has observed how the new FM rock station has altered the electronic environment the radar guns operate under. The signal from this station can affect the readings on the radar guns. It really depends on what day of the week it is, as the station will broadcast at a lower power level when the intended audience is sleeping off last night’s party time.
There is also the problem with householders installing security systems generating spurious signals interfering with the radar guns.
“We know these new security systems affect our radar units, we just don’t know exactly how they do so. So we adjust the radar readings to compensate.”
In addition, different police officers do their own adjusting in the field.
“I can just tell when someone is really speeding. So I’ll adjust the recorded speeds to give a more truthful reading,” says one sheriff.
This is the only law enforcement officer testifying, as the others simply refuse to comply with the court order to appear before the jury.
It is also revealed that the two jurisdictions disagree with one another on how to adjust radar gun readings. Neither can produce any documentation on how the readings are adjusted, let alone the basis for these adjustments.
What do you suppose the jury would do with a case like that?
How would the defense attorney proceed?
What do you think you would do if you were on that jury?
Now instead of a speeding charge, switch gears and think temperature records.
Can you draw any decent conclusions regarding the temperature record at this Australian location?
My conclusion is: we have no idea of what went on here except there have been temperature readings in some given range.
There’s no real evidence of any trend here because the records are so botched up.
You said it well Willis:
“I never guess. It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. — Sir Arthur Conan Doyle, A Scandal in Bohemia”
Spot on!
Current CAGW argument is like measuring a balloon that is inflating and deflating, with different scales and sizes of ruler on differing time-scales and then saying that there is certainty and consensus about the size of the balloon, whether it is inflating or deflating and it is caused by a flea that landed on it farting!
Breaking news from Ozland, Prime Minister Kevin Rudd has stepped down in the face of an internal Labour leadership vote……
http://news.bbc.co.uk/1/hi/world/asia_pacific/10393918.stm
It seems like more of the same obfuscation we see in essentially all of the GISS data. “Homogenization”, “adjusted”, “value-added” data, without any explanation as to the reasoning behind the alteration of the raw data with the end result ALWAYS inducing warming where there was none originally.
Willis did you look at the actual raw data of the Laverton RAAF Vic. station number 087031 monthly max http://www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=36&p_display_type=dataFile&p_startYear=&p_stn_num=087031
monthly min http://www.bom.gov.au/jsp/ncc/cdio/weatherData/av?p_nccObsCode=38&p_display_type=dataFile&p_startYear=&p_stn_num=087031
There is no gap in the data. Station is indicated to have opened in 1941 but data starting in Oct 1943 and the station is still open.
The mean monthly max. is indicated to be 19.7C and the mean monthly min. 9.2C
It appears that there has been an increase in temperatures probably from UHI effect in recent years Ave Min 1944 8.2, 1945 8.9 1946 8.8 –2007 10.5 2008 9.6 2009 10.0
Ave Max 1944 19.4, 1945 18.9, 1946 18.5 –2007 21.3, 2008 20.4, 2009 20.9
My Subaru Forester has a thermometer to give outside temperatures. I regularly measure 2C difference (lower) at night from where I live on 1.5acres (surround by similar properties) compared to the main street of the town 5kms away (population of towns postcode about 40,000). So I would not be surprised by the 2C increase going from war time grass fields to bitumen airstrips surrounded by dense industry and housing.
the late John Daly also did some analysis of Laverton aero — he gives a chart of the seasons here:
http://www.john-daly.com/stations/laverton.gif
and the write up is here:
http://www.john-daly.com/press/press-03c.htm
and there is a bit more of a write up with some pictures of Laverton here:
http://rcs-audit.blogspot.com/2010/03/air-bases.html
There is also an interactive map here that you can zoom in quite close. You can find the weather station (or at least that strange round building it is shown to be near) if you go up towards the top until you get to Sayers Rd and then follow it along until you get to turning bay going towards the top of the picture, and the weather station is down a bit. Actually the siting doesn’t seem that bad on the WUWT scale.
http://www.ourairports.com/airports/YLVT/#lat=-37.855167049756865,lon=144.75531488656998,zoom=19,type=Satellite,airport=YLVT
OT – I could not resist another attack at computer models.
http://www.washingtonpost.com/wp-dyn/content/article/2010/06/21/AR2010062104114_2.html?sid=ST2010062104203
NASA, stay off the Nintendo please.
So, the entire historic temperatures data set clearly needs to be audited by someone neutral and not a typical alarmist.
Any chance of that happening – absolutely not! We can’t have the real figures interfering with the climate models.
It is incredible that the proposal to tax us all back into the Stone Age still has any credibility.
A cardinal rule for dealing with data from a medical experiment, say a comparison between two treatments, is that one must have a clear protocol for dealing with bad data and this protocol must be specified before the data are analyzed (and preferably before the experiment starts). One is not allowed to make up the rules as one goes along even if it leads to perfectly reasonable treatments of the bad data. In the medical context the choice is normally a binary one: a trial participant is either retained or dropped for the analysis. In the surface data context there is a broader choice, but the same principle should apply to the procedures for adjusting surface station data. It should not be acceptable that adjustments, even perfectly reasonable adjustments, are made for each station according to a local best judgment after inspection of the data. One needs an algorithm or in any case unambiguous rules that are applied uniformly to all station data. I think that specific criticisms by Willis here and by Wattsupwiththat in general of surface data adjustments are proper, but the proper response from the surface data folks can not be a case-by-case justification. The only proper justification for any specific surface data adjustments is that the adjustments are prescribed by the algorithm or the rules. Then there can be argument over the content of the rules, or it can be questioned if the rules are indeed applied correctly and uniformly. A case-by-case discussion of adjustments without reference to uniformly applicable rules for the adjustments is besides the point.
where is the next grant coming from?
As I pointed out in the comments to wrt Andrew Watt’s post there is some history available.
This link to Andrew Bolt’s Blogg (21/3/2010) may be of use as it shows some aerial photos of Laverton (Victoria) a couple of years ago and in 1946:
http://blogs.news.com.au/heraldsun/andrewbolt/index.php/heraldsun/comments/could_more_concrete_asphalt_and_industry_have_made_laverton_warmer
The 1946 photo shows open fields so there is clearly the potential for UHI effect when compared with the photo you present.
Wiki says that there was a Grand Prix circuit on the runways in 1948 suggesting that the early training ground was upgraded with sealed runways possibly for heavier jets after WW2 This new activity may account for some of the sharp rise seen in the late 1940s.
Wiki also says the base was decommissioned in the late 1990s which may account for the sharp drop as the base was closed down. The runways were apparently ripped up for housing development. In 2007 the land was released for subdivision as urban sprawl / UHI effect approached. This would explain the rapid rise from early 2000.
I assume there has been quite a bit movement of weather stations during all this. I’m not sure that much of this is as purely evidence-based as you would like but hey, I’m a geologist. We have to work with what we have. But this may provide a starting place for the more rigorously inclined.
The Australian record should be authoritative. All the Aussie records must come from the BOM ab initio. I believe that the “New Climate Data Online” website at the BOM is reasonably close to the raw data record, having done some satisfactory freehand comparisons of Tasmanian stations to published (hardcopy book) BOM Climatic Averages.
The Reference Climate Stations are a subset (one hundred or thereabouts) of the hundreds of Australian climate stations, a subset especially picked for stability, likelihood of being maintained into the future, appropriate siting, and (one assumes) reasonable completeness over the available record time.
It would be very strange for there to be years of missing data in this series in modern times. Apart from anything else, the station is probably needed for ongoing air operations. And it was previously designated an “AMO” or Airport Meteorological Office, meaning that there was an office of BOM staff at the location. If they skived off for years at a time, someone would have noticed…..
So the Laverton data exists and always has existed! Laverton RAAF aka Laverton Aero (BOM ID 087031) starts at 1943, is ongoing at the present time, and switched over to an automatic weather station (AWS) in 1997.
I have the BOM daily min/max temperature CD which confirms the dates of years of record. There’s 11 non-contiguous days of missing Tmin/Tmax data in the 1999-2003 period. Chiefio (chefio.wordpress.com) suggests that GHCNv2 drops whole years if it encounters any missing data. That’s pretty rigorous, if so. I guess it is not known just where in the BOM – GHCN – GISS QC/transfer/homogenisation/combination factory line the Laverton data goes astray.
There’s also some missing daily data prior to 1961, but it’s pretty clean after that. Could some of the GISS traces be (yikes) different versions of the same trace? With different ‘missing data’ treatments? I couldn’t find any other “Lavertons” with the right years of record on a quick search.
I’ve seen the missing data phenomenon before. I was recently checking Forrest AMO Reference Climate Station in Western Australia. GHCN seems to have “vanished” whole years within the past twenty years according to KNMI and GISS. Cold years, as it happens.
My take on the Laverton graph? 1992, 1995 and 1996 were the coldest years in south-eastern Australian in the last twenty years. In Victoria, it looks like they were almost as cold as the chilly 1940s-1950s. (I was stationed in Melbourne in winter 1995. I can confirm it was a bleak, biting winter.) Australian year-to-year annual mean temperatures naturally vary around 2 degrees C over decades, with the big peaks probably corresponding to large or long El Nino events or other warm-ocean events. (Compare the Laverton plot with Ballarat Aerodrome). So the exciting rise from the early nineties to the late 2000s at Laverton is still consistent with natural variation on the Australian continent. We’ve had a decade dominated by El Nino, and some hard drought years, so not surprising we are at the ‘high end’ at the moment.
The vexed question of recording accurate temperatures and the failure to do this initially alerted me to the suggestion that theory of ‘Catastrophic Anthropogenic Global Warming’ is built on extremely shaky foundations. How can the Met Office in the UK justify spending millions of scarce pounds to run forecasting models built on data that is possibly wildly inaccurate?
While in London, my wife and I live in a suburban house with no lawn, just private paved areas and pebble garden behind the house and public areas to the front, but still my daily temp. readings (taken outside in my back yard and in the shade) almost invariably show slightly lower max temps and slightly higher min temps – I use a good quality thermometer, so if the Met Office figures are correct, why are my readings showing less heat during daylight and more heat during darkness when the opposite should be the case if the Met Office corrects for UHI?
And I hope that Anthony’s missing luggage is soon found. Confusing enough to operate out of a suitcase in different time zones, but not to have one’s suitcase to hand can be quite distressing.
If I want to know what the climate was doing in the past, I’ll consult a geologist. If I want a climatic prediction for the future, I’ll best be served by consulting.. a geologist.
Willis Laverton Victoria ceased to be used as an airfield back in the 1990s. The weather station is located well away from runways, buildings and bitumen. However whilst the site is located in a sizable grassed area, the urban fringe of Melbourne now pretty well surrounds the old Laverton Air Force Base. The location is here at the green arrow
Willis,
Some more answers to some questions.
There are missing data in the early years, see this part of 1943 in Tmin:
Year Month Day Tmax Tmin
1943 10 31 17.3 7.6
1943 11 1 18.4
1943 11 2 17.7
1943 11 3 27.8
1943 11 4 20.1
1943 11 5 16.1
1943 11 6 19.6 9.3
1943 11 7 14.4
1943 11 8 14.6
1943 11 9 17.5
1943 11 10 13.8
1943 11 11 16.2
1943 11 12 22.1
1943 11 13 22.2
1943 11 14 23.8 7.9
1943 11 15 23.2
1943 11 16 30.2
1943 11 17 31.6 18.4
1943 11 18 16.9
1943 11 19 17.3
1943 11 20 16.8
1943 11 21 18.2
1943 11 22 20.6 11.1
1943 11 23 19.6 11
1943 11 24 18.2
1943 11 25 17.9
1943 11 26 23.3 12.2
1943 11 27 29
1943 11 28 17.8
1943 11 29 21.3
1943 11 30 17.9
1943 12 1 19.9
1943 12 2 21.9
1943 12 3 24.4
1943 12 4 15.8
1943 12 5 18.3
1943 12 6 22.8
1943 12 7 18.4
1943 12 8 21.7 9.7
1943 12 9 18.6 11.4
1943 12 10 23.2 11.8
1943 12 11 24.3 12.6
1943 12 12 22.2
1943 12 13 21.7 15.7
1943 12 14 18.4
1943 12 15 18.3 10.3
1943 12 16 17.8 11.3
1943 12 17 16.6 12.1
1943 12 18 21.4 12.8
1943 12 19 21.1 9.5
1943 12 20 20.3 7.4
1943 12 21 23.9 9.2
1943 12 22 32.5 7.4
1943 12 23 19.7 8.3
1943 12 24 24.5 8.3
1943 12 25 22.9
1943 12 26 21.1
1943 12 27 22.8
1943 12 28 18.4 11.7
1943 12 29 19.8
1943 12 30 28.8 11.8
1943 12 31 39.2 14.8
1944 1 1 39.3
1944 1 2 25.3
1944 1 3 23.2
1944 1 4 21.6
1944 1 5 21.1
1944 1 6 21.6 12.2
1944 1 7 27.8
1944 1 8 40.1
1944 1 9 24.2
1944 1 10 24.7
1944 1 11 18.2
1944 1 12 20.4
1944 1 13 28.3
1944 1 14 40.8
1944 1 15 23.6
1944 1 16 22.2
1944 1 17 23.8
1944 1 18 23.8
1944 1 19 19.8
1944 1 20 28.3
1944 1 21 39.3
1944 1 22 40.7
1944 1 23 19.9
1944 1 24 19.4
1944 1 25 21.6
1944 1 26 21.6
1944 1 27 21.3
1944 1 28 29.3
1944 1 29 23.8
1944 1 30 24
1944 1 31 29.1
1944 2 1 18.9
1944 2 2 20
1944 2 3 25.9
1944 2 4 26.8
1944 2 5 34.2
1944 2 6 35.8
1944 2 7 29.5
1944 2 8 22.9
1944 2 9 19.4
The cold year in 1949. My official BoM record gives Tmax 17.97 deg C, Tmin 8.32 for an average of 13.14 deg C for the year, after infilling about 12 missing data points of the 730 with intermediate round figures. This agrees with your yellow graph at bottom for Aust data. It does not resemble anything shown for GISS.
The DMS for the Laverton station 087031 are stated as 144 45 24, -37 51 24. If you trust Google Earth, this picks up some instruments 180m south of Sayer’s Rd. If these are the correct instruments, they are 870m bearing 222 deg from the NE end of runway 23. That is, not far to the north of the flight path. However, while Laverton was a busy place in the war years, it ceased to be an official RAAF airport in 1992. I spent some years 5 miles to the South of Laverton at RAAF Point Cook Academy in the the 1959-61 period and took some training at Laverton. It was way out in the wilderness then. We used to spot and shoot rabbits with the landing light from a P51 Mustang mounted on a car roof with a hole cut in it. In 2010 the area is rather suburban, as can be seen on the aerial photo above. Little reason exists to disregard UHI.
There was also a temperature station for a short time at Salines, a few miles South of Laverton, where salt water was evaporated and salt harvested; but the weekend data are much missing. There is also a record of a Laverton Comparison 087177 from 1 Mar 1997 to 31 July 1998. The comparison point seems to have been at 144 44 44, -37 51 59, some 210 m West of the N-S runway 35. I have not cross checked the comparison, but I note it because it seems additional to the Heinz 57 varieties shown for GISS.
I hope this helps with context.
@Alexander K says: June 24, 2010 at 4:26 am
“How can the Met Office in the UK justify spending millions of scarce pounds to run forecasting models built on data that is possibly wildly inaccurate?”
And how can our beloved politicians in the UK (in between slashing and burning benefits and public spending, and hiking taxes and fuel costs) contentedly plan to spend £400 Billion (their figures and no doubt grossly underestimated) on “combatting climate change” and moving to a “low carbon economy”, in response to the MET Office’s ridiculous prophesies based on exceedingly dodgy, cherry picked and “homogenised” data?
Facts? We don’t need no stinkin’ facts! We’ve made up our minds!!!
Limbooloolarat
funny
The University of Melbourne has done actual measurements of melbourne UHI as reported by http://www.earthsci.unimelb.edu.au/~jon/WWW/uhi-melb.html
If this work is correct, and it does not seem to have received objections, the top map shows Laverton in the second or third highest colour zone, with a 6-6.5 degree UHI in 1985-94 Winter (JJA) Mean Minimum.
How far downwind does the ‘wake’ of heat from a built up area affect the temperature over the adjoining rural area? The answer to this is particularly relevant to this discussion about the temperatures at Laverton, but has more general implications as well.
I recently spent a few days tracking temperatures recorded by the Bureau of Meteorology at the Geelong airport (38.22S, 144.33E) compared with those at the Avalon airport (38.03S, 144.48E). Geelong is a provincial city about 47km. SW of Laverton. The Geelong airport is about 1.5km. S of the built up area, and Avalon airport is 8 to 10 km. NNW. Both are rated as high quality automatic stations. Readings are reported at half hour intervals.
The point here is that depending on the direction of the wind, if one is in clear air upstream, then the other is in the wake, so that any differential should be an indication of an extended heat island effect.
What showed up quite clearly was that even at those distances the station in the downwind wake could be up to about 0.5 deg.C higher during much of a day and into the evening.
Laverton is downwind of built up areas when the wind is in any quarter except the NW, which means that the temperature records must reflect the impact of the increasing density of adjacent urbanization over the past fifty years. A separation of even a few hundred meters is apparently quite insufficient to guarantee isolation.
The whole temperature record is work of fiction! If you take the individual works of fiction for each site and combine them, what do you have? The public library, Fiction section!
Interesting UHI adjustment, given the population of the City of Wyndham, the local municipality, has shown the following population growth:
1954 9,414#
1958 10,520*
1961 13,629
1966 18,369
1971 25,116
1976 31,790
1981 40,555
1986 52,458
1991 60,563
1996 73,691
2001 84,861
2006 112,695
Not to mention the increased heat generated by the rising number of cars and gadgets per capita.