Temperatures in Victoria

The size of the 2007 anomaly prompts the question: ‘what (on earth) was going on in Victoria in 2007?’. The second chart (over the fold) shows some ‘outliers’ that may account for the high mean in 2007. The ‘May’ outlier is from that year. The outliers in June (winter in Victoria) are from 1991 and 1957, while the July outlier is from 1975. All were otherwise rather cool years.click for larger image

R coode for the time-series plot

# Go to http://www.bom.gov.au/cgi-bin/silo/cli_var/area_timeseries.pl
# Using the instructions there, define a grid covering Victoria
# (Hint: start by clicking at Lat:142E and subsequently at Long:40S)
# Generate the time series and copy the table to a text editor
# (unfortunately this data set does not seem to be available via ftp)
# Save the table to a text file and move to R
# Read the text file ('file')
# file<-"/bom_data.txt"
# Table 'f' should have 14 Vectors of monthly mean anomalies and an annual anomaly mean
f<-read.table(file,skip=9,fill=FALSE, row.names=1, col.names=c("Year","Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec","Annual"))
# Create a time-series of the annual mean anomaly. Don't include the last (incomplete) 2008 series
anomalies<-ts(f["Annual"],start=c(1950,1), end=c(2007,1))
# plot them using a 'stair step' plot
plot(anomalies, type="S", col="darkorange", lwd=2, xlab="", ylab="degrees c", main="Mean Temp Anomalies (Victoria)", sub="Source:BOM, Grid=142.50: 150.50E, 35.50: 39.50S", cex.sub=0.8, font.sub=3, cex.axis=0.8)
# add a center-line for ease of reference
abline(h=0.0, lty=3, col="darkseagreen", lwd=2)
# add some tick marks -- assumes Hmisc library is loaded

R code for the box-plot (using the same data set)

boxplot(f[1:12], col="darkorange", pch=16, notch=TRUE, boxwex=0.6, cex.axis=0.8, ylab="anomaly, degrees c", main="Mean, quartiles and outliers of monthly records (1950-2007)")<br/> #

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