Daily Surface Ozone data for 1995-1997 Eastern US
These data are used in several publications developing statistical methods for spatial data and for extremes. There were originally obtained from William Cox USEPA through the AIRS data base although these data can be reconstructed by obtaining from the hourly measurements from US EPA AirData and choosing the link to the Air quality system (AQS). ozmax8.rda is an R image object about 600Kb size) that contains daily ozone measurements and related station and date information over the period 1995-1999. See READMEozmax.txt for a description of the list components. The script work.R describes the manipulations of the dates from the original data formats, with original data files in this directory.
Sample R code:To attach the binary datra object in an R session:
attach( "ozmax8.rda")Code to draw the figure above. You will need the fields R package for this.
library( fields) load( "ozmax8.rda") ind<- c(125, 149) # two adjacent stations in Southern Indiana ind2<- years(ozmax8$dates) ==1997 stats( ozmax8$PPB[ind2,])-> look set.panel( 1,2) # nice image plot of seasonal means quilt.plot( ozmax8$lon.lat, look[2,],axes=FALSE, xlab="", ylab="", legend.shrink=.7) points( ozmax8$lon.lat[ind,], pch="o", cex=2, col="magenta") points( ozmax8$lon.lat, pch=".", col="black", cex=2) title( "Seasonal mean 1997") US( add=TRUE, col="grey") # time series plots to check for correlations for stations that are # close. matplot( ozmax8$years[ind2], ozmax8$PPB[ind2,ind], type="l", col=c(1:3), lty=1, ylab="PPB max 8 hour average", xlab="days") title("Two individual stations")