I have collated the Jones et al 1990 temperature data against annual average data from the TR055 data set, reviewing all 84 plots in the format shown below. Here is a plot for Shanghai. The Jones et al 1990 version was plotted first in black and the annual average from TR055 secondly in red. If the match is very close (as here), the second line overwrites the first line, which then doesn’t show. So I also plotted the Jones et al 1990 version with prominent points, emphasizing the identity of the two series in the area of overlap. The Jones et al version only goes from 1954-1983, while the TR055 is longer,beginning in the 19th century (not all of which is shown here) and continuing to 1990. Doug Keenan reports that the station history reports moves.
Here is another example from Qingdao, where the longer TR055 record shows a considerable temperature decrease from the early 1940s to the early 1950s, when Jones et al commenced their study – a change observable in other TR055 stations. The “trend” in this data is sensitive to choice of start and end points and, while I’m sure that there are “good” reasons for the period selected by Jones, it does seem a little opportunistic. Doug Keenan says that the station history is inconsistent.
Here is an example from Chengdu, again showing high values prior to the start of the Jones period; Doug Keenan reports that the station history indicates moves.
In only one case was there a material inconsistency between the TR055 version and Jones et al 1990: Wulumuqi, as shown below. It’s pretty hard to figure out what Jones is doing here. The Jones version (uniquely in this case) lowers the values, perhaps on the basis of an inhomogeneity around 1960. OK, but then their later values from 1973 are identical to the unadjusted values. If the values in the middle were adjusted for homogeneity, shouldn’t the later values be as well? Of course, that would pretty much eliminate the trend, and, as I recall, this was the station with the largest trend in the urban group. Ah, the Team!
I also browsed through comparisons of the TR055 version to the GHCN v2 version. What struck me immediately was just how stale the GHCN v2 data is. Many of the stations have not been updated since TR055 around 1990. Here’s a plot of one Jones station comparing the TR055 version to the version currently at GHCN v2. They are identical. If they aren’t updating this data, what is the money earmarked for updating being spent on?
This is not to say that none of the series are updated. However, the updates in a quick pass often show an alarming lack of continuity. Here’s a typical example. To take an annual average, I required all 12 months to be available. Why would the record through the travails of the Great Leap Forward and the Cultural Revolution be continuous, only to become erratic in the 1990s? Are there inhomogeneities lurking here?
Here’s another example in which later values in GHCN v2 are erratic and again, one wonders about homogeneity. The data on file does indicate relative warmth in the late 1930s-early 1940s, something that one sees in other places. Of course, this is pre-CRU adjustments.
A comment in the most recent CRU survey notes that undocumented homogeneity adjustments may exist in national data prior to CRU handling. If one ever wonders about the potential scale of adjustment, take a look at this spectacular example. So someone has to guess at how to adjust for this.
BTW the documentation for the NOAA gridded data says that they use the “raw” GHCN v2 data (which is what’s plotted here).
In conclusion, I guess what surprised me the most was how stale the data was in GHCN v2. In answer to Willis’ FOI request, the University of East Anglia said that all the Jones station data was available online at GHCN v2. If that’s the case, is CRU also using stale station data? With so much stale data, I wonder how many series are actually driving the temperature results in this area.