co2 <- function(url="ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt",
plot=TRUE,Temp=TRUE) {
# http://cdiac.ornl.gov/ftp/trends/co2/maunaloa.co2
#Mauna.Loa <- read.table(url)
#nrows.co2 <- length(co2.test) - 20
# 1958 3 1958.208 315.71 315.71 314.61 -1
Mauna.Loa <- read.table(url,
col.names=c("year","month","yymm","ave","interp",
"trend","no.days"))
#Mauna.Loa[Mauna.Loa<0] <- NA
co2 <- Mauna.Loa$interp
yy <- Mauna.Loa$year
# yy <- as.matrix(Mauna.Loa[,1])
# yymm <- sort(rep(yy,12) + (rep(1:12,length(yy)) - 0.5)/12)
yymm <- Mauna.Loa$yymm
years <- as.numeric(rownames(table(yy)))
ny <- length(years)
CO2 <- rep(NA,ny)
for (i in 1:ny) {
ii <- is.element(yy,years[i])
if (sum(ii)==12) CO2[i] <- mean(co2[ii],na.rm=TRUE)
}
use <- yymm > 1900
yymm <- yymm[use]
co2 <- co2[use]
yy <- yy[use]
if (plot) {
plot(yymm,co2,type="l",lwd=2,col="green",
main="Mauna Loa CO2",xlab="Time",ylab="concentration (ppmv)")
grid()
points(yymm,co2,pch=19,cex=0.5)
if (Temp) {
data(T2m.ncep)
i1 <- is.element(years,year.ncep)
i2 <- is.element(year.ncep,yy)
c <- cor.test(stand(log(CO2[i1])),T2m.ncep[i2])
print(c)
}
dev.new()
plot(yymm,stand(Mauna.Loa$trend),type="l",lwd=3,col="green",
main="Mauna Loa CO2 & NCEP T(2m)",xlab="Time",ylab="standardised",
sub=paste("Cor=",round(c$estimate,3),"p-value=",round(c$p.value,3)))
grid()
points(yymm,co2,pch=19,cex=0.35,col="grey")
lines(year.ncep,stand(T2m.ncep),lwd=2)
dev2bitmap("co2_t2m.png",res=150)
}
results <- list(year=years,CO2.am=CO2,yymm=yymm,co2=co2)
invisible(results)
}
Keelercurve <- function(
url="ftp://ftp.cmdl.noaa.gov/ccg/co2/trends/co2_mm_mlo.txt",
urlbg="http://www.realclimate.org/images/raffinery.jpg") {
#require(jpeg)
if (!file.exists("raffinery.jpg"))
download.file(urlbg,"raffinery.jpg")
img <- readJPEG("raffinery.jpg")
Mauna.Loa <- read.table(url,
col.names=c("year","month","yymm","ave","interp",
"trend","no.days"))
#Mauna.Loa[Mauna.Loa<0] <- NA
co2 <- Mauna.Loa$interp
yy <- Mauna.Loa$year
# yy <- as.matrix(Mauna.Loa[,1])
# yymm <- sort(rep(yy,12) + (rep(1:12,length(yy)) - 0.5)/12)
yymm <- Mauna.Loa$yymm
dev.new(width=10,height=8)
par(bty="n",xaxt="n",yaxt="n",mar=rep(0,4),fig=c(0,1,0,1))
plot(yymm,co2, type='n')
rasterImage(img, 0.999*min(yymm), 0.99*min(co2),
1.001*max(yymm), 1.01*max(co2))
lines(yymm,co2,lwd=11,col="white")
lines(yymm,co2,lwd=9,col="grey30")
text(mean(yymm),max(co2),"CO2 concentrations (Mauna Loa)",font=2,cex=1.75)
text(min(yymm),min(co2),"1958",col="white",pos=4)
text(max(yymm),min(co2),"1958",col="white",pos=2)
dev2bitmap("CO2.png",res=150)
}
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