I did not expect to be looking at these again until the beyond the end of this month, but a friend pointed out a curious change that has happened yet again to these figures. This relates to my provious post 1880 IS getting colder!
Just to refresh your memory this is the data I am looking at:
Bear in mind that when the temperature data has been changed off that page there does not appear to be an archive. The version that I pasted into my One Note pages is dated and timed 17 November 2012 23:53 (UTC by the way)
I have created a copy of it here: GLB.Ts+dSST_20121117-235300.txt
Just six days later, pn the 23rd November the file looks like this:
That one is saved directly from the web page exactly as it appears there.
The change is very small – I am looking the the figure for 1880 here, but nevertheless it is a change, and as usual a change downwards. I have not been able to find a satisfactory explanation of these changes. I accept that the very latest back a few years may change, but NOT the very earliest NOR in a period of 6 days!
Bear in mind that the NCDC site says of how often the data is updated:
10. How often and when is the global average temperature dataset updated?
The dataset is updated every month. Data for a month are typically made available by the 15th of the following month.
As you can see the change is very small, and does not affect the annual 1880 anomaly figure this time, but across the whole spread there is again a very minute adjustment downwards to earlier figures. This is the chart for the data of the 17th and the data of the 23rd compared – Annual mean anomalies. The differences are all before the 1951 and are very slight but are ALL downwards.
Bear in mind that where blue appears above red the anomaly has been increased (lowered in temperature).
I shall be keeping a close eye on this over the next few months!