. It is one type of the misdirections used by climate science that cause me to be distrustful of their results.
with my mea culpa out of the way...
Blogger gets hot and bothered over Nasa's climate data error | Environment | The Guardian
Jeff.Samano On Today's Issues: NASA: 1934 Hottest Year on Record
any reasonable person would admit that pre-1999 data have indeed been changed.
the emphasised portion above is for you edthecynic. it relates to your smear of Christie and Spencer
and for anyone who wants the actual data in numerical form-
http://data.giss.nasa.gov/gistemp/graphs/US_USHCN.2005vs1999.txt 1999vs2005
http://www.john-daly.com/GISSUSAT.708after Y2K corrections
You would think that after your sources burned you with the misdirection of their blink chart you would be at least as. distrustful of them as you are of climate scientists, but no you swallow their BS whole in your defense of Christy and Spencer.
The error from using the opposite sign to correct for diurnal satellite drift, an error that cannot be made by accident by an "expert" on satellite calculations as the pair bill themselves, was much greater than their error noted above. The numbers went from +.047 degrees C/decade to +.138 degrees C/decade.
I notice that you still haven't admitted that pre-1999 data were changed when the Y2K bug was fixed. Do you still deny that they were? I mean come on now. Even Gavin Schmidt says they were.
As to Spencer and Christie- start a thread, state your case, put up a few links and then we can debate it a while.
Why should I admit to something YOU know is not true!
And Gavin Schmidt said no such thing!
The pre 1999 data was changed long before the year 2000 error was found in 2007.
Data.GISS: GISS Surface Temperature Analysis (GISTEMP)
Some improvements in the analysis were made several years ago (Hansen et al. 1999; Hansen et al. 2001), including use of satellite-observed night lights to determine which stations in the United States are located in urban and peri-urban areas, the long-term trends of those stations being adjusted to agree with long-term trends of nearby rural stations.
Current Analysis Method
The current analysis uses surface air temperatures measurements from the following data sets: the unadjusted data of the Global Historical Climatology Network (Peterson and Vose, 1997 and 1998), United States Historical Climatology Network (USHCN) data, and SCAR (Scientific Committee on Antarctic Research) data from Antarctic stations.
The basic analysis method is described by Hansen et al. (1999), with several modifications described by Hansen et al. (2001) also included. Modifications to the analysis since 2001 are described on the separate Updates to Analysis.
Graphs and tables are updated around the 10th of every month using the current GHCN and SCAR files. The new files incorporate reports for the previous month and late reports and corrections for earlier months. NOAA updates the USHCN data at a slower, less regular frequency; we switch to a later version as soon as a new complete year is available.
The GHCN/USHCN/SCAR data are modified in two steps to obtain station data from which our tables, graphs, and maps are constructed. In step 1, if there are multiple records at a given location, these are combined into one record; in step 2, the urban and peri-urban (i.e., other than rural) stations are adjusted so that their long-term trend matches that of the mean of neighboring rural stations.
Urban stations without nearby rural stations are dropped.
Data.GISS: GISS Surface Temperature Analysis (GISTEMP) -- Updates to Analysis
Several minor updates to the analysis have been made since its last published description by Hansen et al. (2001). After a testing period they were incorporated at the time of the next routine update.
The only change having a detectable influence on analyzed temperature was the 7 August 2007 change to correct a discontinuity in 2000 at many stations in the United States. This flaw affected temperatures in 2000 and later years by ~0.15°C averaged over the United States and ~0.003°C on global average. Contrary to reports in the media, this minor flaw did not alter the years of record temperature, as shown by comparison here of results with the data flaw ('old analysis') and with the correction ('new analysis').
RealClimate: 1934 and all that
1934 and all that
Filed under: Climate Science Instrumental Record — gavin @ 10 August 2007
Another week, another ado over nothing.
Last Saturday, Steve McIntyre wrote an email to NASA GISS pointing out that for some North American stations in the GISTEMP analysis,
there was an odd jump in going from 1999 to 2000. On Monday, the people who work on the temperature analysis (not me), looked into it and found that this coincided with the switch between two sources of US temperature data. There had been a faulty assumption that these two sources matched, but that turned out not to be the case. There were in fact a number of small offsets (of both sign) between the same stations in the two different data sets. The obvious fix was to make an adjustment based on a period of overlap so that these offsets disappear.
This was duly done by Tuesday, an email thanking McIntyre was sent and the data analysis (which had been due in any case for the processing of the July numbers) was updated accordingly along with an acknowledgment to McIntyre and update of the methodology.
The net effect of the change was to reduce mean US anomalies by about 0.15 ºC
for the years 2000-2006. There were some very minor knock on effects in earlier years due to the GISTEMP adjustments for rural vs. urban trends. In the global or hemispheric mean, the differences were imperceptible (since the US is only a small fraction of the global area).
More importantly for climate purposes, the longer term US averages have not changed rank. 2002-2006 (at 0.66 ºC) is still warmer than 1930-1934 (0.63 ºC – the largest value in the early part of the century) (though both are below 1998-2002 at 0.79 ºC).
