bomsoi {DAAG} | R Documentation |
The Southern Oscillation Index (SOI) is the difference in barometric pressure at sea level between Tahiti and Darwin. Annual SOI and Australian rainfall data, for the years 1900-2001, are given. Australia's annual mean rainfall is an area-weighted average of the total annual precipitation at approximately 370 rainfall stations around the country.
bomsoi
This data frame contains the following columns:
Australian Bureau of Meteorology web pages:
http://www.bom.gov.au/climate/change/rain02.txt and http://www.bom.gov.au/climate/current/soihtm1.shtml
Nicholls, N., Lavery, B., Frederiksen, C. and Drosdowsky, W. 1996. Recent apparent changes in relationships between the El Nino – southern oscillation and Australian rainfall and temperature. Geophysical Research Letters 23: 3357-3360.
plot(ts(bomsoi[, 15:14], start=1900), panel=function(y,...)panel.smooth(1900:2001, y,...)) # Check for skewness by comparing the normal probability plots for # different a, e.g. par(mfrow = c(2,3)) for (a in c(50, 100, 150, 200, 250, 300)) qqnorm(log(bomsoi[, "avrain"] - a)) # a = 250 leads to a nearly linear plot par(mfrow = c(1,1)) plot(bomsoi$SOI, log(bomsoi$avrain - 250), xlab = "SOI", ylab = "log(avrain = 250)") lines(lowess(bomsoi$SOI)$y, lowess(log(bomsoi$avrain - 250))$y, lwd=2) # NB: separate lowess fits against time lines(lowess(bomsoi$SOI, log(bomsoi$avrain - 250))) detsoi <- data.frame( detSOI = bomsoi[, "SOI"] - lowess(bomsoi[, "SOI"])$y, detrain = log(bomsoi$avrain - 250) - lowess(log(bomsoi$avrain - 250))$y) row.names(detsoi) <- paste(1900:2001) par(mfrow = c(1,2)) plot(log(avrain-250) ~ SOI, data = bomsoi, ylab = "log(Average rainfall - 250)") lines(lowess(bomsoi$SOI, log(bomsoi$avrain-250))) plot(detrain ~ detSOI, data = detsoi, xlab="Detrended SOI", ylab = "Detrended log(Rainfall-250)") lines(lowess(detsoi$detrain ~ detsoi$detSOI)) par(mfrow = c(1,1))