CA reader Geoff Sherrington, an Australian scientist, sends the following email exchange with Phil Jones in early 2006 (original post here). Geoff observes:
there is a reluctance to answer direct questions with direct answers and a lot of red herrings thrown in. Readers can deduce what they like from the exchange, where Phil says he no longer has the data used in early papers. Contrast this with the statement next from Australia’s Bureau of Meteorology (Blair Trewin, April 2006 email to me):
From: Geoff Sherrington
Sent: Fri 3/24/2006 12:09 PM AUS
Subject: Early global temperature data
I seek the figures which were used from Australian weather stations at the start of your climate modelling work in the 1980s. I seek to know the first set of Australia weather stations used in modelling, plus the set that was rejected and if possible, the span of data by years (or the data itself) for each of the stations considered and eventually used initially.
Is it possible to obtain this information?
Geoffrey H Sherrington
To: Geoff Sherrington
Cc: Sheppard Sylvia (SCI) ks918
Sent: Saturday, March 25, 2006 4:20 AM UK
Subject: FW: Early global temperature data
Dear Geoffrey, We no longer have the Australian station date we were using in the early 1980s. At that time we had a limited network. In the 1990s, the Australian Bureau of Meteorology began issuing a lot more station data each month. Up to that time it had been about 40 stations internationally. Through contacts with personnel in Melbourne, we got access to the back data from all the new stations, so added these. In order to use temperature data, we need historic series with at least the 1961-90 base period. We now have access to over 100 stations from BoM in real time.
I wish more countries would release more data in real time like Australia. Some have, but not that many – and none release extra data in Africa, South America and southern Asia. We have managed to get extra historic data though in South Africa, Argentina and Brazil. We got the latter, though, on the agreement that we didn’t pass the data onto others, but we can use them in our gridded data. This condition also applies to a number of European countries – again only historic data, no real time. Australia is the only country to make additional data (additional to the about 1500 exchanged by Met Services) to us in real time.
I have looked back at a publication where we adjusted station records for homogeneity in the mid-1980s. We didn’t omit any Australian series then, but adjusted the following sites: Darwin, Townsville, Thursday Island, Gladstone, Forrest, Adelaide, Sydney and Norfolk Island. We still have these adjustments.
In the mid-1990s, we compared our Australian temperature with a series developed by Neville Nicholls (then of BMRC, he has retired in the last few months and now works at Monash) and a student he had. Over the period from 1901-1992 we had a correlation of our two series of 0.92 and with no difference in trend over these 92 years. This work was done before we got the additional station data (so in effect we had about 40 stations, whereas Neville and the student had almost 200). I can’t recall the student’s name (Simon ?).
So, I can’t send you anything. We don’t have the earlier station data now.
AUS 24/03/2006 23:31
Geoff Sherrington to Phil Jones
I was working on early Australian temperature records going back to the 1880s when the first global models were being constructed. I share the general concerns in this Internet quote, but not necessarily the figures: The central contention of these pages is that for over a decade the IPCC has published global temperature trends distorted by purely local warmth from Urban Heat Islands (UHI’s). These spurious trends have been promoted as “smoking gun” evidence of greenhouse warming. The data were generated by Dr. P.D. Jones and others (1986, 91 & 94), mainly from the Climatic Research Unit (CRU) of the University of East Anglia at Norwich in the UK. The CRU and the IPCC claim that our atmosphere has warmed by 0.6 to 0.8 degrees Celsius since the late 19th Century, and ascribe most of this to an enhanced greenhouse effect.
For example, most of the early data from the 1880s to the 1950s were rejected because the weather stations were not housed in approved cases or were otherwise deemed unreliable. There were over 100 weather stations available, but in the first model(s) only about 10 were used from Australia, most in large cities.
Today, there is a most unscientific trend to ignore the raw data and to apply statistical algorithms to improve the data. This has the danger of generating artefacts and I have no doubt that it does. In particular, heat island effects continue to cause problems and the maths i have read for their correction are highly suspect.
The early Australia data might not have come from approved weather station cases, but very many of the sites showed a slight temperature reduction from ca 1880 to 1950. The weather station cases would not have been the cause of this uniform decrease. These data are valuable, because, properly used, they extend back in time the trends that are apparent and potentially allow the resetting of a reference starting date for Australian surface temperatures around 1880 instead of 1980 or whatever is the current backwards limit for “acceptable data” now. We thought that the maximum and minimum surface temperatures for Australia had imperceptible to slight downwards change from 1880 to 1985 or so as recorded by the bulk of the stations, especially when sudden discontinuities were removed if they happened at different times at different locations or were documented as instrument changes.
In short, I feel that the early climate models used selective data to stampede the policy makers into belief in global warming, prematurely. What say you to that?
From: Phil Jones
To: Geoff Sherrington
Sent: Monday, March 27, 2006 8:57 PM
Subject: Re: Early global temperature data
First, I’m attaching a paper. This shows that it is necessary to adjust the marine data (SSTs) for the change from buckets to engine intakes. If models are forced by SSTs (which is one way climate models can be run) then they estimate land temperatures which are too cool if the original bucket temps are used. The estimated land temps are much closer to those measured if the adjusted SSTs are used. This doesn’t address in any way your questions, but I thought I’d send it to you.
Back to Australia: there is a serious problem with Australian temperatures before the early 1900s because of the screens used. Unlike NZ, the various Australian states didn’t switch over to Stevenson screens very early and when the change occurred it was different in different states. The work undertaken by Neville Nicholls and the student sought to find the 200+ best stations across the country.
We’ve not rejected any Australian stations. The ones we use from BoM though start around the 1900 period. All of those we had in the early 1980s we still use. In Fig 2 of the other attachment, there is a time series for Australia. We have adjusted some, but these adjustments cancel. Since the paper in 2003, we’ve added in lots more Australian data, as I mentioned before. The trend of Australian temperatures though has not changed in its overall character. In the mid-1980s the extra data (above the 40 or so) were not available to us.
Climate models don’t use observational data. They are longer running versions of weather models. They don’t get given any observational data – except in the case of the SSTs in the first paper I’ve attached. As I said this is one way climate models can be run. Another way is to include the ocean, so they determine their own SSTs.
At 01:11 28/03/2006, Sherrington wrote:
Dear Phil, I continue to assert that there were well over 100 long-term surface weather site records from Australia available to the public in Australa because I have been in touch with a scientist who compiled some of it into a paper. The data frequently extend back to the 1880s.
In Jones et al 1986, I have quickly counted the actual Australian stations used and found 34 or so. Some of these start in the 1880s (especially those in Graph 2 below, where a steady temperature increase is shown on average) but about half or more, by eyeball, start about 1951. I have lived in several of these places before 1951, so they are not new towns.
Two graphs derived from this 1985-1990 period follow. They show the potential for wrong results through selectivity and the potential for artefacts from population use of energy near weather stations (heat islands). The absence of Stevenson screens cannot dismiss the Graph 1 cooling trend from 1882 to 1951. Of the 25 stations in graph 1, only Darwin was in Jones et al 1986. That means that 24 plausible data sets were excluded. (There were ore than that).
What a coincidence that all these averaged data show a slight increase from 1951 onwards, the same cutoff year as applied by Jones at al in many other cases. Surely there is a strong case for the start point for calculations of changes in climate to extend back to the 1880s and not suddenly commence in the 1950s.
There is a whole mathematical branch of statistics named “Geoststistics” which is particularly suitable for discerning if an observation at one place has predictive value for another location. (e.g. for comparing nearby stations for heat island effects). Do you know if this method has been applied to climate modelling?
Regards Geoff Sherrington Scientist, Melbourne
Geraldton, Narrabri, Hay, Albany, Rottnest Island Lighthouse, Walgett,
Deniliquin, Bourke, Cape Naturaliste Lighthouse, Coonabarabran,
Echuca, Cooma, Darwin, Moruya Heads Pilot Station, Omeo, Dubbo, Alice
Springs, Gabo Island Lighthouse, Bathurst, Strathalbyn, Mt. Gambier,
Yamba, Wilsons Promontory Lighthouse, Newcastle Signal Station, Cape
Sydney, Melbourne, Brisbane, Perth, Adelaide, Hobart
From: Phil Jones
To: Geoff Sherrington
Sent: Tuesday, March 28, 2006 8:53 PM
Subject: Re: Early global temperature data
The Australian data were not available to us in the mid-1980s. Even if they were we were concentrating on getting data and back data for other parts of the world (particularly the tropics, Africa and South America, where we didn’t have anything). Just because data are available in a country doesn’t mean we have them. The Australian Weather Bureau now releases lots more data than it did. In the 1980s, it was releasing about 40 stations.
As an aside, your expectation that we had the data isn’t unusual. We get requests from a number of scientists in countries (mainly developing ones or from the ex-USSR and eastern Europe) to send them their own national datasets. Their met services haven’t got their own national data digitised in many cases, although the situation is improving, but only slowly.
We searched the literature in the 1980s, but more importantly searched a number of data archives (proper archives such as libraries), particularly that at the UK Met Office to digitise additional data. We also managed to get some from national met agencies. We continue to do this and add in new datasets as and when we get the data. For example, Canada has a project to homogenize all their station and precipitation (daily and monthly) series. They sent us all the final adjusted series and we include them in our database – about 250 series. We got the data through scientific contacts at meetings in the late 1990s. All the adjusted data are not in the GHCN archive in Asheville, partly because they (Asheville) have never asked for them. If you ask for Canadian data now you get the adjusted data, but only from Environment Canada. NCDC (Asheville) and GISS still use the unadjusted Canadian data. We do the best we can, but we’re not some global archive. I guess NCDC is the official archive as recognized by WMO and GCOS, but they don’t have resources to fund anyone chasing countries for improved past data.
Back to the early Australian data: I mentioned the other day that there are problems with the early Australian data. If you look at the pdf I sent earlier (Figure 2, panel f) you’ll see that climate models given SSTs can’t reproduce Australian land temps (the black line) prior to around 1910. The models can in other continents of the world. Most importantly for Australia, they can over NZ. I would suggest you look at NZ temperatures. The attached paper sort of does this, but only as a part of other regions of the S. Pacific. There are earlier papers by Folland and/or Salinger on NZ temperatures. What is clear over this region is that the SSTs around islands (be they NZ or more of the atoll type) is that the air temps over decadal timescales should agree with SSTs. This agreement between SSTs and air temperatures also works for Britain and Ireland. Australia is larger, but most of the longer records are around the coasts.
So, NZ or Australian air temperatures before about 1910 can’t both be right. As the two are quite close, one must be wrong. As NZ used the Stevenson screens from their development about 1870, I would believe NZ. NZ temps agree well with the SSTs and circulation influences.
Finally, geostatistics is being used somewhat in climatology. It isn’t being used in climate modelling – which is using GCMs and RCMs. You seem to have a broader definition of climate modelling.
At 07:39 31/03/2006, Sherrington wrote:
“Back to the early Australian data: I mentioned the other day that there are problems with the early Australian data. If you look at the pdf I sent earlier (Figure 2, panel f) you’ll see that climate models given SSTs can’t reproduce Australian land temps (the black line) prior to around 1910. The models can in other continents of the world. Most importantly for Australia, they can over NZ. etc.”
An important geographical difference between Australia and New Zealand is that Australia has a hot interior and New Zealand has a cold interior. If you consider weather stations near the coastline, the daily shapes of the weather logs (id examined say hour by hour) might well be different, so that an analysis of the maxima and minima might not reflect heat flux comparably in both countries. If the land and the nearby sea have different thermal inertias, this could well explain the differences you are reporting. But this is only a guess as I do not know your present detailed methodology. The same comment applies to all historical analyses based in maxima and minima, be they daily, monthly or yearly. They are merely indicators of flux and in the final analysis might all be inadequate for reconstructions.
Seems to me that there is a need to devise contemporary experiments that look at the hourly patterns, in places that geostatistics has established a probability of connectivity and predictability.
Phil Jones to Sherrington
I’ve found another paper you should look at. I can’t get the pdf as it has been back-scanned yet. It is a paper by Neville Nicholls et al. in the International Journal of Climatology, Vol 16, 705-710 (1996). This talks about the exposure of early Australian temperature data in the different states.
One of the most interesting of the comparisons of the screens (old and new) was undertaken at Adelaide for over 60 years. Whether Adelaide has an urban effect is irrelevant to this. The two screens are the same site. There is a plot (Figure 1) of the difference. The figure caption isn’t very clear but the text is. The plot is for the difference between the Glaisher/Greenwich stands which were common in most of Australia up to the 1910s and the Stevenson screen. For minimum temperature the difference is relatively small and has little seasonal cycle (Stevenson warmer by about 0.1 deg C). For the maximum though there is a marked seasonal cycle, with the Stevenson screen cooler by about 1 deg C in summer months, reducing to about 0.2 cooler in winter months. I realise this is just Adelaide, but this is the longest set of paired readings anywhere in the world. It clearly indicates the old screens are too warm. Maybe other shorter comparisons were made in other areas.
There are similar problems in Spain before about 1900. Here they just switched to Stevenson type screens between 1900 and 1910 (varying between sites) with no overlap. However, there are pictures of the old stands (based on a French model) with dimensions/instructions etc. So what a group has done is to build two new ones and install them at the sites of two stations (La Corunna and Murcia – opposite sides of Spain to get a little idea of differences in the different climates). The results from 2 years of overlap show remarkable consistencies between the two years and some similarities between the sites. The maximums are much more affected – also about 1deg C warmer in the rebuilt’ old screens compared to the conventional ones. Minimum temperature differences are on the opposite sign and much smaller – very similar to Adelaide.
Finally, if you don’t think you can compare Australia with NZ, then compare Tasmania with NZ. Many Tasmania records are near to the coast and they should agree with SSTs around the island, when averaged to annual or decadal values.
I’ll be away next week at a meeting in Europe. I’ll likely have some email but little time, so will only be answering the more urgent emails. I’ll be back to the normal the week after.
Finally Geoff sends the following response from Australia’s Bureau of Meteorology (Blair Trewin, April 2006 email)
“At last count there were 74 stations which have at least some digital temperature data (mostly monthly) available in 1890 (GS comment – this must be a typo meaning 1980), plus a handful of stations which had opened and closed before then. The data from these stations should be publicly available (and I can’t see any reason why any data that was available in the mid 1980’s would not be now – in fact the reverse would be true). It is likely that a number of other stations (possibly about 100) took at least some pre-1890 temperatures, but most of these records were probably short and of doubtful quality.
I think Phil Jones may have digitised some monthly data himself for the 1986 data set – I know this is true for Alice Springs as we only digitised the 1879-1924 data from there in the last couple of years.”