extRemes (version 1.61)

Ozone4H: Ground-level ozone order statistics.

Description

Ground-level ozone order statistics from 1997 at 513 monitoring stations in the eastern United States.

Usage

data(Ozone4H)

source

Data was originally provided by the U.S. EPA (http://www.epa.gov/epahome/ozone.htm), and can be obtained (daily maximum 8-hour average ozone for all five seasons from 1995 to 1999) from the Geophysical Statistics Project (GSP) at the National Center for Atmospheric Research (NCAR) at

http://www.cgd.ucar.edu/stats/data.shtml

along with the orignal longitude/latitude coordinates for the stations.

Details

Ground level ozone readings in parts per billion (ppb) are recorded hourly at ozone monitoring stations throughout the country during the "ozone season" (roughly April to October). These data are taken from a dataset giving daily maximum 8-hour average ozone for 5 ozone seasons (including 1997). The new U.S. Environmental Protection Agency (EPA) National Ambient Air Quality Standard (NAAQS) for ground-level ozone is based on a three-year average of fourth-highest daily 8-hour maximum ozone readings (see http://www.epa.gov/air/criteria.html).

For more analysis on the original data regarding the U.S. EPA NAAQS for ground-level ozone, see Fuentes (2003), Gilleland and Nychka (2005) and Gilleland et al. (2005b). For an example of using these data with extRemes, see Gilleland et al. (2005a). These data are in the form required by the rlarg.fit function of Stuart Coles available in the R package ismev; see Coles (2001) for more on the r-th largest order statistic model and the function rlarg.fit.

References

Coles, Stuart. An Introduction to Statistical Modeling of Extreme Values. Springer-Verlag, London, 2001.

Fuentes, Montserrat. Statistical assessment of geographic areas of compliance with air quality. Journal of Geophysical Research, 108(D24), 2003.

Gilleland, Eric and Nychka, Douglas. Statistical Models for Monitoring and Regulating Ground-level Ozone, Environmetrics, 16:535--546. 2005.

a) Gilleland, Eric and Katz, Richard W. Tutorial for the 'Extremes Toolkit: Weather and Climate Applications of Extreme Value Statistics.' http://www.assessment.ucar.edu/toolkit, 2005.

b) Gilleland, Eric, Nychka, Douglas, and Schneider, Uli. Spatial models for the distribution of extremes, Applications of Computational Statistics in the Environmental Sciences: Hierarchical Bayes and MCMC Methods Edited by J.S. Clark & A. Gelfand. Oxford University Press, 2005. (to appear)

Examples

data(Ozone4H)
str(Ozone4H)
plot(Ozone4H)
# See the extRemes tutorial (Gilleland et al. (2005a)) for a much better example (uses the GUI windows).