##SEA ICAE
   		
  ##LOAD FRM NOAA 1979 to present 
     #ftp://sidads.colorado.edu/DATASETS/NOAA/G02135
	month1=as.character(1:12); y=nchar(month1);temp=(y<2);month1[temp]=paste("0",month1[temp],sep="")
	month0=c("Jan", "Feb", "Mar", "Apr" ,"May" ,"Jun", "Jul", "Aug" ,"Sep", "Oct" ,"Nov", "Dec") 
	hemi=c("N","S")
 
   seaice=NULL
   for(j in 1:12) {
     for (k in 1:2) {	
	url="ftp://sidads.colorado.edu/DATASETS/NOAA/G02135" #/Apr/N_04_area.txt"
	loc=file.path(url, month0[j],paste(hemi[k],"_",month1[j],"_area.txt",sep="") )
	fred=readLines(loc)
	year=as.numeric(substr(fred,1,4))	
	temp1=!is.na(year)&(year>=1978)
	fred=fred[temp1];year=year[temp1]	
	test=data.frame(year, as.numeric(substr(fred,6,7)),substr(fred,27,27), as.numeric(substr(fred,29,34)),as.numeric(substr(fred,36,41)) )
	names(test)=c("year","month","N","area","extent")
	seaice=rbind(seaice,test)
	}
	}
   	dim(seaice) #352 5 
	order1=order(seaice$N,seaice$year,seaice$month)
	seaice=seaice[order1,]
 	temp=(seaice$N=="N")
	X=seaice[temp,]
	names(X)[4:5]=paste(names(X)[4:5],"N",sep="_")
	X$area_S=seaice$area[!temp]
	X$extent_S=seaice$extent[!temp]
	seaice=X[,c(1,2,4:7)]
	seaice$time=seaice$year+(seaice$month-.5)/12
     	seaice$GLB=seaice[,3]+seaice[,5]  
		#GLB=area_N+area_S
	
     #GLB anomaly    
	m0=tapply(seaice$GLB,seaice$month,mean,na.rm=TRUE);m0	
		#      1        2        3        4        5        6        7        8        9       10       11       12 
		#19.76000 18.46933 19.93500 22.15200 24.15433 25.85241 26.24069 25.46414 25.49793 27.36828 27.39267 24.37621 
	seaice$norm=factor(seaice$month);levels(seaice$norm)=m0
	seaice$norm=as.numeric(as.character(seaice$norm)) #monthly average 
	seaice$anom.GLB=round(seaice$GLB-seaice$norm,2)
	plot(seaice$time,seaice$anom,type="l",ylab="GLB Area Anomaly",xlab="")

     #SH anomaly 
	m0=tapply(seaice$area_S,seaice$month,mean,na.rm=TRUE) #SH 
	seaice$norm=factor(seaice$month);levels(seaice$norm)=m0
	seaice$norm=as.numeric(as.character(seaice$norm))
	seaice$anom_SH=round(seaice$area_S-seaice$norm,2)

      #NH anomaly
	m0=tapply(seaice$area_N,seaice$month,mean,na.rm=TRUE) #NH 
	seaice$norm=factor(seaice$month);levels(seaice$norm)=m0
	seaice$norm=as.numeric(as.character(seaice$norm))
	seaice$anom_NH=round(seaice$area_N-seaice$norm,2)

##PLOT OF ANOMALIES BY HEMISPHERE TRIPARTITE
	nf=layout(array(1:3,dim=c(3,1)),heights=c(1.2,1.,1.3))
	par(mar=c(0,3,2,1))
	plot(seaice$time,seaice$anom.GLB,type="l",ylab="SH Area Anomaly",xlab="",axes=FALSE)
	axis(side=1,labels=F);axis(side=2,las=1);box();abline(h=0,lty=2)
	title("Sea Ice Anomaly (NOAA)")
	text(1979,-1.5,"GLB",pos=4,font=2)

	par(mar=c(0,3,0,1))
	plot(seaice$time,seaice$anom_SH,type="l",ylab="SH Area Anomaly",xlab="",axes=FALSE)
	axis(side=1,labels=F);axis(side=2,las=1);box();abline(h=0,lty=2)
	text(1979,1.2,"SH",pos=4,font=2)

	par(mar=c(3,3,0,1))
	plot(seaice$time,seaice$anom_NH,type="l",ylab="SH Area Anomaly",xlab="",axes=FALSE)
	axis(side=1,labels=T);axis(side=2,las=1);box();abline(h=0,lty=2)
	text(1979,-1.0,"NH",pos=4,font=2)

##PLOT OF AREAS BY HEMISPHERE TRIPARTITE
	nf=layout(array(1:3,dim=c(3,1)),heights=c(1.2,1.,1.3))
	par(mar=c(0,3,2,1))
	plot(seaice$time,seaice$GLB,type="l",ylab="",xlab="",axes=FALSE,ylim=c(10,30))
	axis(side=1,labels=F);axis(side=2,las=1);box();abline(h=mean(seaice$GLB),lty=2)
	title("Sea Ice Area (NOAA)")
	text(1979,18,"GLB",pos=4,font=2)

	par(mar=c(0,3,0,1))
	plot(seaice$time,seaice$area_S,type="l",ylab="",xlab="",axes=FALSE,ylim=c(0,20))
	axis(side=1,labels=F);axis(side=2,las=1);box();abline(h=mean(seaice$area_S),lty=2)
	text(1978,18,"SH",pos=4,font=2)

	par(mar=c(3,3,0,1))
	plot(seaice$time,seaice$area_N,type="l",ylab="",xlab="",axes=FALSE,ylim=c(0,20))
	axis(side=1,labels=T);axis(side=2,las=1);box();abline(h=mean(seaice$area_N),lty=2)
	text(1978,18,"NH",pos=4,font=2)