Playing hide and seek behind the trees

Still Hiding the Decline

by Steve McIntyre

Even in their Nov 24, 2009 statement, the University of East Anglia failed to come clean about the amount of decline that was hidden. The graphic in their statement continued to “hide the decline” in the Briffa reconstruction by deleting adverse results in the last part of the 20th century. This is what Gavin Schmidt characterizes as a “good thing to do”.

First here is the Nov 2009 diagram offered up by UEA:

Figure 1. Resized UEA version of Nov 2009, supposedly “showing the decline”. Original here ,

Here’s what UEA appears to have done in the above diagram.

While they’ve used the actual Briffa reconstruction after 1960 in making their smooth, even now, they deleted values after 1960 so that the full measure of the decline of the Briffa reconstruction is hidden. Deleted values are shown in magenta. Source code is below.

Figure 2. Emulation of UEA Nov 2009, using all the Briffa reconstruction.

R SOURCE CODE:

##COMPARE ARCHIVED BRIFFA VERSION TO CLIMATEGATE VERSION

#1. LOAD BRIFFA (CLIMATEGATE VERSION)

 # archive is truncated in 1960: ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/n_hem_temp/briffa2001jgr3.txt”

loc=”http://www.eastangliaemails.com/emails.php?eid=146&filename=939154709.txt”

 working=readLines(loc,n=1994-1401+104)

 working=working[105:length(working)]

 x=substr(working,1,14)

 writeLines(x,”temp.dat”)

 gate=read.table(“temp.dat”)

 gate=ts(gate[,2],start=gate[1,1])

#2. J98 has reference 1961-1990

 #note that there is another version at  ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/jones1998/jonesdata.txt”

loc=”ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/jones2001/jones2001_fig2.txt”

 test=read.table(loc,skip=17,header=TRUE,fill=TRUE,colClasses=”numeric”,nrow=1001)

 test[test== -9.999]=NA

 count= apply(!is.na(test),1,sum)

 test=ts(test,start=1000,end=2000)

 J2001=test[,"Jones"]

#3. MBH :  reference 1902-1980

 url<-"ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/mann1999/recons/nhem-recon.dat"

 MBH99<-read.table(url) ;#this goes to 1980

 MBH99<-ts(MBH99[,2],start=MBH99[1,1])

#4. CRU instrumental: 1961-1990 reference

 # use old version to 1997 in Briffa archive extended

 url<-"ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/n_hem_temp/briffa2001jgr3.txt"

 #readLines(url)[1:50]

 Briffa<-read.table(url,skip=24,fill=TRUE)

 Briffa[Briffa< -900]=NA

 dimnames(Briffa)[[2]]<-c("year","Jones98","MBH99","Briffa01","Briffa00","Overpeck97","Crowley00","CRU99")

 Briffa= ts(Briffa,start=1000)

 CRU=window(Briffa[,"CRU"],start=1850)

 tsp(CRU) #  1850 1999  #but starts 1871 and ends 1997

 delta<-mean(CRU[(1902:1980)-1850])-mean(CRU[(1960:1990)-1850]);

 delta  #   -0.118922

 #used to get MBH values with 1961-1990 reference: compare to 0.12 mentioned in Climategate letters

#get updated version of CRU to update 1998 and 1999 values

 loc="http://hadobs.metoffice.com/crutem3/diagnostics/hemispheric/northern/annual"

 D=read.table(loc) #dim(D) #158 12 #start 1850

 names(D)=c("year","anom","u_sample","l_sample","u_coverage","l_coverage","u_bias","l_bias","u_sample_cover","l_sample_cover",

 "u_total","l_total")

 cru=ts(D[,2],start=1850)

 tsp(cru) #  1850 2009

#  update 1998-1999 values with 1998 values

 CRU[(1998:1999)-1849]= rep(cru[(1998)-1849],2)

#Fig 2.21 Caption

 #The horizontal zero line denotes the 1961 to 1990 reference

 #period mean temperature. All series were smoothed with a 40-year Hamming-weights lowpass filter, with boundary constraints

 # imposed by padding the series with its mean values during the first and last 25 years.

 #this is a low-pass filter

 source("http://www.climateaudit.org/scripts/utilities.txt") #get filter.combine.pad function

 hamming.filter<-function(N) {

 i<-0:(N-1)

 w<-cos(2*pi*i/(N-1))

 hamming.filter<-0.54 – 0.46 *w

 hamming.filter<-hamming.filter/sum(hamming.filter)

 hamming.filter

 }

 f=function(x) filter.combine.pad(x,a=hamming.filter(40),M=25)[,2]

## WMO Figure at CRU

 #http://www.uea.ac.uk/mac/comm/media/press/2009/nov/homepagenews/CRUupdate

 #WMO: http://www.uea.ac.uk/polopoly_fs/1.138392!imageManager/1009061939.jpg

 #2009: http://www.uea.ac.uk/polopoly_fs/1.138393!imageManager/4052145227.jpg

X=ts.union(MBH=MBH99+delta,J2001,briffa=briffa[,"gate"],CRU=cru )  #collate

 Y=data.frame(X); year=c(time(X))

 sapply(Y, function(x) range(year [!is.na(x)]) )

 #      MBH J2001 briffa  CRU

 # [1,] 1000  1000   1402 1850

 # [2,] 1980  1991   1994 2009

smoothb= ts(apply(Y,2,f),start=1000)

xlim0=c(1000,2000) #xlim0=c(1900,2000)

 ylim0=c(-.6,.35)

 par(mar=c(2.5,4,2,1))

 col.ipcc=c("blue","red","green4","black")

par(bg="beige")

 plot( c(time(smoothb)),smoothb[,1],col=col.ipcc,lwd=2,bg="beige",xlim=xlim0,xaxs="i",ylim=ylim0,yaxs="i",type="n",axes=FALSE,xlab="",ylab="deg C (1961-1990)")

 usr 1960

 points( c(time(smoothb))[temp],smoothb[temp,"briffa"],pch=19,cex=.7,col=”magenta”)