2o14 adjusted (qca) data going missing late February:
2012 adjusted (qca) and unadjusted (qcu) data going missing, reverting back to 2008, with adjusted data first passing through 2011, reappearing sometime in January 2013:
January 2012 value first recorded as 1.95°C, with code “a” indicating one day missing in calculation of monthly mean, then as 2.28°C with no days missing. The missing day would need a temperature of at least 12.03°C to effect this change, but TMAX for January 2012 is only 7.09°C, the maximum TMAX for January is 8.28°C in 1932 (February also changes at the same time with no indication of missing days, March loses a day, April has a “suspicious looking” 9.99°C with one day missing, which later changes to 10.13°C, still with one day missing):
As I noted in a previous post I have noticed some GHCN data collection issues in the specific context of Irish stations. These include missing values, incorrect values, and past values going missing, being found (or changed), going missing again, being found again, …
For simplicity throughout this post I refer to GHCN rather than to NOAA or NCDC.
Such problems could arise at the originating stage, transmission of the relevant data from the Irish meteorological service. I have however, in one of the cases described below (Valentia Observatory), followed the data abroad to both GHCN and http://www.ogimet.com, and found that on the same dates the CLIMAT messages at Ogimet decoded correctly, giving the value recorded by the Irish meteorological service, whereas the corresponding values shown by GHCN changed from day to day, and were incorrect. This would seem to indicate that valid data was being sent out, and that the problem arose elsewhere. This ‘elsewhere’ may not necessarily be at GHCN – data is also provided through third parties. The end result however remains missing or incorrect data, wherever this may have arisen or gone missing. Continue reading
As completion of this post was long delayed, I’m posting the discussion part separately here as an ‘aside’ post so that it will show up as a new post for anyone who has given up waiting.
The most striking aspect of this Krasnojarsk adjustment study is the variation in the trend imposed on the urban record by the different choices made for adjusting rural stations. This is not unique to Krasnojarsk, but the number of stations being reclassified by the different choices is greater here than for other stations which I have examined. Continue reading
Paul Homewood has a post Cooling The Past In Siberia , where I commented. This post adds some further information to my comments, with images which I could not post inline at Paul’s blog, and more detailed information about the adjustment process involved for Krasnojarsk. For a detailed worked example of the Gistemp adjustment process, see my posts: Post 1 of 6 in GISTEMP example and following posts through post 4, and the additional example, Dublin Airport adjustment. Continue reading
Michael Mann has an op-ed in the NYTimes If you see something, say something. Closer to home, John Gibbons, at one time a regular Irish Times columnist, now an occasional one, recently re-tweeted on similar lines: Continue reading
GHCN monthly data (v2 or v3) may not always be quite what it seems. Consider Nitchequon (Canada: 40371826000), looking here at the five individual time series in GHCN v2:
Some missing years – but where’s the problem? Continue reading
This post is published now for “historic interest” as the issue is no longer relevant with the GISTEMP change to use GHCN v3 adjusted data as input. Some familiarity with GISTEMP STEP1 processing and log files is virtually essential to follow the detail below, although some idea of the difference in combined station time series which may arise as a result of different tie-breaking strategies may be gained by examining the two alternative series added after the e-mail to GISS included below. For this station, Palma, using an alternative tie-breaking strategy reduces the temperature in the early years of the combined record by 0.8 degrees when compared to the GISS GISTEMP combined record. As we approach the present both combined records will show the same values. In the case of Palma the alternative tie-breaking strategy reduced the temperature at the start of the combined record when compared to the standard GISS GISTEMP, but of course for other stations the alternative tie-breaking strategy increased as well as reduced early temperatures. Palma was selected for this e-mail (and post) as the station showing the greatest change from the standard GISS GISTEMP when using this particular alternative tie-breaking strategy. It is of course quite possible that a different alternative tie-breaking strategy might produce an even greater difference for this or some other station. Continue reading