angech | July 7, 2014 at 10:59 pm | Reply
Judith, I and others I’m sure would like to do a more formal rebuttal of Zeke’s approach if allowed and only if well written and argued.
Mine would focus on 3 key points.
The first of adjustment of past temperatures from current ones.
The second of a possible flaw in TOBS as used.
The third on the number of what are referred to a Zombie stations
1. Zeke says this is incremental and unavoidable using current temperatures as the best guide and adjusting backwards.
“NCDC assumes that the current set of instruments recording temperature is
accurate, so any time of observation changes or PHA-adjustments are done
relative to current temperatures. Because breakpoints [TOBS] are detected through pair-wise comparisons, new data coming in may SLIGHTLY change the magnitude of recent adjustments by providing a more comprehensive difference series between neighboring stations.
When breakpoints are removed, the entire record prior to the breakpoint is
adjusted up or down depending on the size and direction of the breakpoint.
This means that slight modifications of recent breakpoints
The incremental changes add up to WHOPPING changes of over 1.5 degrees over 100 years to past records and 1.0 degree to 1930 records. Zeke says the TOBS changes at the actual times are only in range of 0.2 to 0.25 degrees. This would mean a cumulative change of 1.3 degrees colder in the distant past on his figures, everywhere.
Note he is only technically right to say this ” will impact all past temperatures at the station in question though a constant offset.”
But he is not changing the past 0.2 degrees.It alters all the past TOBS changes which cause the massive up to 1.5 degrees change in only 100 years.