Ozone4H               package:extRemes               R Documentation

_G_r_o_u_n_d-_l_e_v_e_l _o_z_o_n_e _o_r_d_e_r _s_t_a_t_i_s_t_i_c_s.

_D_e_s_c_r_i_p_t_i_o_n:

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

_U_s_a_g_e:

     data(Ozone4H)

_F_o_r_m_a_t:

     A data frame with 513 observations on the following 5 variables.

     _s_t_a_t_i_o_n a numeric vector identifying the station (or line) number.

     _r_1 a numeric vector giving the maximum ozone reading (ppb) for
          1997.

     _r_2 a numeric vector giving the second-highest ozone reading (ppb)
          for 1997.

     _r_3 a numeric vector giving the third-highest ozone reading (ppb)
          for 1997.

     _r_4 a numeric vector giving the fourth-highest ozone reading (ppb)
          for 1997.

_D_e_t_a_i_l_s:

     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
     <URL: 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'.

_S_o_u_r_c_e:

     Data was originally provided by the U.S. EPA (<URL:
     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

     <URL: http://www.cgd.ucar.edu/stats/data.shtml>

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

_R_e_f_e_r_e_n_c_e_s:

     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.' <URL: 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)

_E_x_a_m_p_l_e_s:

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

