In 2007 I started monitoring a few GISS stations. Amundsen-Scott, Vostok, Halley, Davis in Antarctica. Then a few more over the years. It was just to check some of the claims of data changing. Also to see if I could plot the temps over time. Some small changes at first, but nothing of concern.
In 2008 I added more stations such as Nuuk, to check more claims. It is easy to save the temp files for each station. Picking a few stations at random points around the GISS globe, up to about 12.
Goddard was right. Past data points were changing. Usually small amounts on a monthly basis. Some station data did not change at all, but only the new monthly data were added.
In 2009 I was saving monthly data for 15 stations.Every month the most recent data is added to the end of each file. But, scanning past data it became apparent that some historical station data was being “revised” almost completely. That means that a time plot shifted by enough to notice on a temperature plot. Usually the “new” plot showed that the past became cooler. Small amounts, maybe one tenth of a degree. When I got to 20 stations, I noticed that one or two sets of data were being extensively revised every month. At the end of 2009 there was a sudden revision of more stations by larger amounts. Almost always the data before 1960 was getting cooler.
By 2010 I was up to 30 stations, plus the Antarctic four.
Akureyri, Bartow, Beaver City, Concordia, Crete NE, Ellsworth, Franklin, Gothenburg, Hanford, Honolulu, Hilo, Jan Mayen, Kodiak, Kwajaalein, La Serena, Loup City, Minden, Nantes, Nome, Norfolk Island, Nuuk, Red Cloud, St. Helena, St. Paul, Steffenville, Thiruvanantha, Truk, Wakeeny, Yakutat, Yamba.
Downloading 30 sets of temperature data to save. Then putting all data into an excel file to make plots. Then comparing time plots to see where individual data points had changed. It became clear that a regular revision of about 10 percent of all GISS stations was taking place on a monthly basis.
Every month in 2010, three of the 30 stations has changes to past data points that were visible by plotting. Looking at every point for every station is not possible, but scanning at random shows that many stations have small changes. 2011 was about the same, but at the end of 2011 was another substantial change to many stations.
In early 2012 my 10 year old hard drive died. I had a separate backup, but it was found to be virus infected to the extent that I could not save all data. I still have the drive and can open some files but can’t copy files to another drive.
In 2012 GISS began making larger changes to more past data. Some stations were showing monthly changes that could only be described as “erratic” with some large shifts for a couple months, followed by data returning to values from months earlier. Sometime in December 2012 was a very large change in past data for many stations. Some stations showed data that stopped in 2007 or 2008. In March 2013 those stations were suddenly “restored” and resumed showing complete data up to March 2013.
Every month GISS changes past data by small amounts to some historical data. Some stations are being selected for larger revisions at random times. For some stations, portions of data from decades ago vanishes completely. The numbers are replaced with “999.9″ indicating no data. Months later those same past data points re-appear, just as they were before, sometimes with small adjustments. If what is happening to a sample of 30 stations is any indication of the entire GISS data set, then I’d say that there is an Orwellian plot to manipulate the past.
There is no record of these past changes, it would be impossible to verify or reproduce those changes. Over the years, the past keeps getting colder.