CRU Smoking Gun? Applying the Artificial Correction

Anthony Watts has located the active Fortran print routine, which is actually titled: "Apply Artificial Correction":

Snippit from: harris-tree/briffa_sep98_e.pro (see the end of the post for the full source listing)

;
; APPLY ARTIFICIAL CORRECTION
;
yearlyadj=interpol(valadj,yrloc,x)
densall=densall+yearlyadj
;
; Now plot them
;
filter_cru,20,tsin=densall,tslow=tslow,/nan
cpl_barts,x,densall,title='Age-banded MXD from all sites',$
xrange=[1399.5,1994.5],xtitle='Year',/xstyle,$
zeroline=tslow,yrange=[-7,3]
oplot,x,tslow,thick=3
oplot,!x.crange,[0.,0.],linestyle=1
;

I'm not fluent in Fortran, so any judgement I might try to make on this routine would be dangerous. Watts' claim is that the artificial correction is being applied to the data at the very last minute - as it is being printed.

If this is so, then the correction is not a true correction in the sense that individual data points are adjusted to compensate for specific individual failures of calibration, etc. This would be a case of compensating an entire data set in order to achieve a global, non-data-centric objective. In fact, here is Watts' plot of the adjustments being made to the data set as it prints.




Any Fortran experts out there? What do you see here?

Watts agrees that there is no information indicating that this fudge was used for anything important. It is another data point of interest.