GISS and BoM temperature adjustments
Click here for the raw GISTEMP data for the town of Esperance on the south coast of Western Australia. Note that GISS includes data from December of the previous year (2008) to calculate its meteorological year. Below is data extracted for the year 2009:
The missing September 2009 data raises questions about how GISS has arrived at its SON calculation of 17.5.
The correct average mean temperature for Esperance in September 2009 is available from the Australian Bureau of Meteorology. This is the GISS data source and there is total agreement between the GISTEMP and BoM databases for all months and locations.
So the September 2009 average mean temperature missing from the GISTEMP calculations is 13.2, which happens to be the third coldest September since their Esperance records began in 1969.
The correct SON 2009 average mean temperature can be calculated with this accurate September information:
SON = 13.2 + 16.5 + 20.1 / 3 = 16.6
The GISTEMP SON of 17.5 is almost a degree too high and the new Esperance annual average for 2009 is 16.87, not 17.1.
This shows a chilly September 2009 average mean temp at 13.9, meaning the Kalgoorlie-Boulder SON works out to be 19.4, not the 20.5 that GISS has calculated using the "missing" September data. So the annual mean for Kalgoorlie-Boulder in 2009 was 19, not 19.28 as calculated by GISS.
Chilly September 2009 mean temperture once again at 13.9, so the Perth Airport SON works out to be 17.2, not the 17.7 calculated by GISS from the "missing" September data. The annual mean for Perth Airport was 18.75, not 18.88 as calculated by GISS.
For example, Esperance August 2009 average mean min up from 8.3 to 8.8, max from 17.7 to 18.1; Kalgoorlie-Boulder August 2009 min up from 6.8 to 7.2, max from 20.3 to 20.7; and Perth (metro, not airport) min up from 8.8 to 9.3, max from 18.5 to 18.9.
The GISS data for Esperance and Kalgoorlie-Boulder in August 2009 is the BoM database bug-corrected data. August 2009 was the hottest August ever recorded in Australia.
The figures above are what was published on the web by GISS on Monday, October 4 2010, for Kalgoorlie-Boulder during 2009. Early on Tuesday, October 5 2010, the GISS adjusted all 2009 monthly figures for that location (possibly other years but these were not monitored by me the previous day).
Data for the 12 months of 2009 in Kalgoorlie-Boulder can be compared as recorded by GISS on October 4 and then on October 5 2010:
The BoM data proves it was actually 19, yet the GISS has adjusted its erroneous calculation up by a further .1 C, even though it is 10 months after 2009.
The GISS database records for Eucla show missing data for December 2009, but the BoM data for December 2009 shows the mean temperature was in fact 21.6 during that month. The GISS has calculated the Summer 2009/10 (D-J-F) mean at Eucla as 22.8 C, but with the accurate BoM December data included it turns out to be 22.7 C.
The GISS database records for Geraldton Airport show missing temperature for April 2010 but the BoM data for April 2010 shows the mean at 20.95, which means the Autumn 2010 M-A-M is 21.3 C, not 21.5 C as calculated by GISS.
The GISS database records for Port Hedland show missing temperature for May 2010 but the BoM data for May 2010 shows the mean at 25.2, which means the Autumn 2010 M-A-M is 29 C, not 29.1 C as calculated by GISS.
The GISS database records for Albany Airport show missing temperature for February 2009. However, there are no records in the BoM website archive for months before September 2009, so the correct temperature isn't known.
The GISS database is sourced via GHCN Monthly Version 2 published by the National Oceanic and Atmospheric Administration, which has error codes for the WA stations referenced on this page.
If GISTEMP adjustments to compensate for "missing" monthly temperature recordings in the Australian database are consistent for similar "missing" data in all countries, the GISTEMP analysis is corrupt and has a strong upward bias.
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